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Tuning cars, driving cars, testing parts, and complaining about everything. It's my job, and a the majority of my non-work life too...
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THIS STRANGE LOOKING INLET MANIFOLD HAS WON PIKES PEAK AND A WHOLE LOT OF RALLYCROSS EVENTS...12/29/2017
Since I created the StavTech YouTube Channel (Click here!) I planned to put everything on there from now on, as unlike here, there's money to be made, and I need to make a living after all, BUT some things just work better as words, so I've decided some things will be on the website regardless (plus Facebook and Instagram), so here we go... A few weeks ago I saw a post where a bunch of retro-rallycross fans were confused about the strange 'loop the loop' inlet manifold in the above picture (by rallycross photography legend Eddi Laumanns), and were discussing what the hell it was all about. I replied and explained exactly what it was, but I got the feeling they didn't really believe me. It was only once someone posted a clearer pic that proved I wasn't talking out of my arse that they finally seemed to accept it. BUT the whole situation made me think it's ideal as a cool bit of tech for you lot, so here it is! This funky looking inlet manifold is used only on certain variations of one engine, the XU8T, which is the 16 valve turbo race engine version of the PSA (ie Peugeot + Citroen) XU series of engines that are found in countless production cars, and was first used (unless very late spec 205 T16 Evo2 Group B engines used the same? If so I've never seen one!) on the 1987 Pikes Peak 205 T16, ie this one... It was then used the year after in the 1988 Pikes Peak winning Peugeot 405 T16, the world famous car driven by Ari Vatenen which starred in the famous 'Climb Dance' video. In fact, here's a few pics of this inlet as fitted to the 405 T16 Pikes Peak winner... The next time this inlet was seen on a car was in Matti Alamäki's 205 T16 E2 rallycross monster in 1989, which made well over 550bhp from it's 1760cc (I understand? Slightly less than the GrpB versions for some reason?) engine... Soon after this it also found it's way in to Jean Luc Pailler's Citroen BX4TC rallycross monster... And after a good few years Jean Luc Pailler pretty much swapped the engine and running gear in to the BXs replacement in the production car world too, the Xantia, where it was used for the number of years in the 1990s... ANYHOW! Enough of the history lesson... What the FUCK is that crazy looping inlet all about then? Well, it's actually a lot more 'normal' than you might think...! As crazy as it looks, all this inlet really is, is a variable length inlet manifold like a lot of production cars have these days, albeit a super trick one running two sets of individual throttle bodies, really long runners (which should have a far greater effect than typical ones), and a boost-operated (rather than rpm) switchover point. Variable length inlet manifolds are quite common these days, used on everything from MX5s to Ferraris. As you probably know, in conventional inlet designs, longer inlet runners tend to improve low rpm performance at the expense of high rpm performance, short runners improve high rpm at the expense of low rpm performance, but a good variable length inlet should be the best of both worlds. The common myth is that inlet length makes no difference to turbo engines, hence why it's rare to see factory turbo cars with them, but in reality it makes a difference no matter what; it's just turbos are so good at making a wide powerband, and masking flaws in an engines powerband, that they're rarely used on boosted engines. Rarely used or not, it doesn't take Sherlock Holmes to work out that if Peugeot, who were one of the world leaders in turbocharged motorsport at the time, used it on multiple Pikes Peak cars, including an outright winner, and then it was used for about another decade in high end rallycross, it's fair to say it had a very worthwhile effect- They didn't fit stuff for fun or just guessed at that level, that's the stupid shit road car tuners do, not them! The main reason they fitted this inlet to these engines was to improve low rpm performance via the long runners, which has the positive side-effect of spooling the turbo faster, while also having the switch-over to short runners, shorter than most typical non adjustable inlets, for maximum high boost high rpm power. The engines this inlet was used on were as small as 1760cc and up to only about 2.1ltr, but all made somewhere between 550 and 800bhp depending on the application; we're talking really big turbos that needed all the help they could get to spool, especially for the tight and twisty rallycross and Pikes Peak events they were used in. So, what are we actually looking at here? Well the top-down shot of it mounted in the Citroen BX is a good one to check out... Follow the boost pipes! The air comes from the filter (bottom right), through the Kevlar inlet pipe, and in to the turbo compressor housing (top centre). It then leaves there and enters the chargecooler (top right), then heads down to a centrally mounted plenum as part of the inlet manifold this feature is about (middle right). Just to the left of the central plenum are 4x individual throttles, one per cyl, but these aren't the engines main throttles, these are simply to block the short inlet runners, forcing the air to go around the long looping runners you see exiting the right hand side of the centre plenum. The aforementioned throttles are opened at a set boost pressure via the turbo wastegate style actuator you can see painted black on the right hand side of the inlet, near the air filter outlet. The engine itself also has 4x conventional throttles, one per cyl, but they're mounted VERY close to the inlet ports, and are pretty much invisible in the above shot, but you can see the the springs and rods that operate them on cam cover. For a MUCH clearer view of both sets of throttles, which will also easily show you how the inlet works, check this pic out... This style of inlet isn't seen in modern motorsport anymore, mostly as modern anti-lag systems are so effective at spooling turbos, which makes setups like this a bit redundant for most race works race engines which have pretty unlimited budgets.
Having said that, this style of inlet makes no noise, adds no engine stress or heat, and is purely mechanical, so for us road car based people, indeed for race car people without a works race team budget, variable length inlets do potentially have a worthwhile use on turbo cars, despite what many people think...! Or do you (think you!) know better than Pikes Peak winners...? (Hint- You don't!) I was all set to do a big feature on the fact that, while low down and mid-range torque makes a car nice to drive, easier to drive fast, and is handy if you got the traction to use it, it's mostly BHP that makes a vehicle fast. That's providing you can stay in the powerband in your BHP car of course- And if not, it's not torque winning races, it's because you've got a massively flawed setup that's losing you races. BUT it turns out I did one of those features about a year ago! If you've not already read that, check it out first, as that covers 99% of the points so no need to repeat myself. Check it out HERE- bhp-sells-cars-torque-wins-races-total-bollocks.html ANYHOW, I found some performance data from when I timed some tuned Turbo Diesels at Bruntingthorpe Proving Ground some years ago, and I think it explains my point well. Of course, the results are just as relevant to low rpm low BHP high torque V6 and V8 petrol engines too, so that's what Part 1.5 is all about. Basically, torque FEELS fast. Even my 1.9TDI PD100 Skoda Fabia daily driver FEELS quite quick, as it's got 180lb/ft at barely over idle, so you put your foot down, turbo spools, and it accelerates very hard at low rpm. Try that in something like a typical performance 2ltr car, say a EP Civic Type-R, and it will accelerate slowly and not feel fast at all. But does that mean my Fabia is faster than a Type-R? Fuck no. Not unless the Type-R driver doesn't know how to change gear and is driving around at low revs. Even though at peak torque a Type-R is a good 30lb/ft down on my shitbox Fabia, it's got about 200bhp, so, as long as the driver is in the ~6000rpm+ rev range, it will leave me for dead like I'm not moving. Diesels often SEEM like they're faster than a lot of cars when on the road too, and that's because cruising rpm and maximum performance rpm are about the same. You're pottering along in 6th in your tuned TDI, getting your great MPG, and you see a something quick you want to try and race come up behind you. All you have to do is put your foot to the floor, and fuck me, off you go in a cloud of smoke and big torque, and next thing you know you've 'won the race' and you're screaming "No smoke no poke bitches! Black smoke racing! WOOOOOOO!" to yourself like a fucking lunatic and you've left the bird in the S2000 wondering what the fuck just happened. Why'd you leave the other car for dead so easy? Because unless they'd already dropped 2 or 3 gears (3 for anything N/A with a small high rpm rev range) ready to race you, which is unlikely, fuck, even less likely as most typical car drivers wouldn't even realise they'd need to do that to go fast, you've left them for dead before they even realise they're in the wrong gear. But what would happen if they were in the powerband? Well, if you've got similar or more power to weight, you will likely win, but if you've got a torquey diesel but making less power, you're still gonna lose a 'fair' race. When it comes down to it, it's your POWER, more specifically POWER TO WEIGHT, that is the big key providing the cars are in the rev range. Saying a diesel is faster as it's faster up to 4000rpm is like saying some hunk of shit 1ltr petrol car is faster than a quick diesel just because it's faster from 5000rpm on. Unless your car hasn't got gears, or you don't know how to drive, neither are excuses. ANYHOW, ON TO THE DATA I WAS ON ABOUT... Back in 2010 Redline did a 'Diesel Special' issue, and one thing we did was time 3x Seat Ibiza TDIs in different stages of tune. We did this to see, or prove even, if it is worth tuning diesels. I think we all know the answer to that, and it's FUCK YES. Diesel tuning gives massive gains over the original performance, and unless you go totally spastic you keep your drivability and economy too- In fact as a daily tuned car, esp if you do a lot of motorway driving, a tuned diesel makes the most sense of all- Great all-round fun daily cars. The thing is, what this feature ALSO shows, is how fast, without any bullshit like both cars starting from 1500rpm in 6th, how hard these cars, all with huge amounts of torque, accelerate. And the answer is pretty much what I said in Part 1 of this feature, and indeed in this 1.5- Only about as fast as a petrol one with the same BHP PER TON would... Ignoring standing start times, which are never going to be good for 2wd cars with tons of torque unless you've got drag tyres, let's look at the most real world, not traction limited, and easy to compare times, 60mph, to 100mph. So, let's start with a stock PD130 Ibiza 60-100mph time (real time, not bullshit speedo time)- It's over 20 seconds. Not fast, 230lb/ft of torque or not. An EP Type-R, with only 145lb/ft, is 9.6sec, in fact other similar hot hatches like Clio 200s and R53 Mini Cooper S's also do it in the ~10sec range. A late spec Mazda 3 MPS is 8.2sec, but has over 50bhp more. So what about with some minor mods, to 145bhp and a pretty huge 270lb/ft- About the same torque a Ferrari 360 has, and that does 60-100mph in a touch over 5sec, and is over 150kg heavier than an Ibiza TDI! Well, 60-100mph time is 19seconds now, very noticeably quicker, but still, nowhere near as fast as the similar weight cars with more BHP. In fact, it's about as fast as other similar weight cars with 145BHP, funny that... So what about when we do about the most common level of tune for TDIs, ie a remap, intercooler, and exhaust? In this state of tune they have around 180bhp and a bonkers 310lb/ft, the same power as the 1.8ltr 20V turbo petrol Seat Ibiza Cupra model, and that does 60-100mph in about 12sec, but the Cupra has 130lb/ft less torque than this, so... Oh fuck me, lo and behold, it's WAY faster than the less tuned one, it's a legit quick car, but despite mental torque, it's 60-100mph acceleration is almost identical to a 180bhp Cupra. A 180bhp car is as fast as another 180bhp car? Surprise? Well, no. Last, and deffo not least, as it was legit rapid, a semi-stripped Ibiza TDI with 245bhp and 410lbft! An Audi R8 V10 has 20lb/ft less torque than that, and weighs about 500kg, half a ton, more, and is 60-100mph in about 4.5sec. SURELY, IF torque wins races (Spoiler alert! It fucking doesn't!), surely being half a ton lighter and having 20lb/ft more would make you way faster, right? AND THE RESULTS ARE! Well, unsurprisingly, it's about as fast as a 245bhp ~1100kg car would be! It's rapid, it's mental fast vs the stock car, but it's 60-100mph time was 8.8seconds- Much faster than hot hatches with ~40bhp less, and, lo and behold, what a similar BHP PER TON hot hatch does. Funny that! I raced him in a Lexus IS-F (A fucking fast car- I did 60-100mph in 6sec in it that same afternoon) afterwards, and it was bizarre only being able to pull away from what looked like a Mum's school run diesel from 30-120mph fairly slowly (destroyed it beyond 120 as TDI ran out of gears, but to be that close is still a FAST car), but it wasn't the torque that made it that fast, it was the fact it was a pretty light (IS-F is 1700kg!) 245bhp car! I think we all know diesels can be CRAZY fast, fuck me, the Darkside Developments Seat Arosa TDI runs 9sec quarter miles at ~150mph! But it ain't the torque as such (But power IS torque and rpm combined), it's the fact it weighs nothing and has well over 500bhp! Check it out, it's fucking mental.... I think between what was said in PART ONE, and the results from this one, says it all.
Torque is useful, torque is enjoyable, torque is fun, torque feels fast... ...But does TORQUE WIN RACES? FUCKING FUCK NO, BHP WINS RACES! ACTUALLY... Torque and RPM combined win races, because... Torque x RPM ÷ 5252 = POWER As we all know and have experienced, the car world is a hive of bullshit and excuses, as people can never admit anything is their fault, so either blame the car or someone else. From people blaming poor performance on a misfire when it's actually shit driving or them lying about how quick their car really is, to companies not honouring a warranty by making some kind of excuse to blame it on user-error- Excuses are a 'car thing'. The inspiration for this mini-feature was hearing one of the most ridiculous excuses I've ever heard, and something that I'd not heard for about 15 years, and even back then it blew my mind someone supposedly respected had the balls to claim this... Step back to 15 or so years ago, and the first example of this was about the Skyline GT-R RB26DETT engine, and most notably the ceramic turbine wheels the turbos have, which are known to snap off the shaft or shatter to many pieces. While the above is an unfortunate and common fact, one of the big name tuners of the time used to convince their followers they needed an engine reubild as soon as this happened, as bits of the turbine wheel will have been 'sucked' in to the engine. Some of you right now might be thinking "Well can it?", and some others are thinking "WTF?", so let's break it down in to a way even a tuning novice can understand...
Fast forward to today, and I heard a very similar thing, used as another bullshit excuse, but actually even more far-fetched in my eyes. The basic story is an engine has severe pitting (IMO severe detonation, but that doesn't matter for this) on the squish/quench pads on all cylinders on a turbocharged engne, and on the exact same opposite areas on the pistons too. No marks anywere else- Untouched bores, untouched centres of pistons, untouched valves, untouched combustion chambers- Basically only the areas most affected by det. Certain people (And to make it even more stupid, these people AREN'T the tuner either! This is honestly people just trying to defend him off their own back, despite it not being strictly blamed on him- Retarded or what) flatly refuse to see it as detonation, and claim it's FOD (Foriegn object damage), and back that up by the fact ONE of the cylinders has broken a piece of valve guide off in an inlet port. My comment was "Even IF somehow it can only damage areas either side of the piston/chamber without touching the center or the bores, how can FOD in one cylinder account for the same damage in all the others?" The reply was "Doesn't matter which cylinder was damaged, if one goes they're all going to get damaged as the metal will travel back up the inlet manifold and in to the other cylinders" Again, some of you are already thinking "WTF", as it's probably even more far fetched than the first, despite being said by a bit of a hero of the tuning scene, so let's once again break it down...
So yeah, more utter shit. The WORST thing about all this kind of crap is though, is that this isn't words of random idiots, the 2nd example wasn't even from a tuner making an excuse either- This is coming from RESPECTED names in the modified car world, 'FAMOUS' names some might say, and because they're "Somebody", people blindly believe them, despite it being insanely far fetched.
My question of it all is, do they BELEIVE what they're saying, or are they LYING? Either way it is REALLY fucking bad considering they're influential, aspirational, whatever the fuck you want to call them, names, in this stupid hobby we all have. And this is exaclty why I'm hugely skeptical of what even 'Big' names say, partly by being untrustworthy, partly by not knowing as much as you think (or they'd like you to think) they'd know. It's terrible really, being a skeptic or having trust issues isn't a good thing, and it'd be amazing if this tuning world was just people being honest and helping, but instead the kind of people and the kind of advice in the tuning scene is a big reason why so much of it is fucking awful and so slow progressing. You have 2 choices, you can either listen to these people and be one of the crowd getting ripped off or having mediocre stuff, or you can take everything you hear with a pinch (ok, a fucking huge road gritter full) of salt, and fact check stuff from even supposed big and trustworthy names, which should, while it's a lot of work, get you a seriously good car. While it's popularity and media coverage is increasing in recent years (Yet it was on prime time TV on in the 70s and 80s- A long way to go before it's back at this level!), Rallycross is, in my eyes anyhow, the most under-rated motorsport there is. And more than under-rated, it's genuinely fun to watch, and by far the most relevant to UK tuning fans of any motorsport. Formula One is world famous and has the biggest budget of any motorsport, but is it exciting to watch? Not really. And it's all so secret that any possible relevance to the tuning we all do we either won't know about for decades, or never will. WRC cars in 2017 will be the most powerful than they've been since the GroupB days, but it's still not a great spectator sport, despite being hugely famous and featuring wild cars. BTCC is hugely popular in the UK, and as circuit racing goes, it's pretty badass, but in my eyes it's not even a patch on Rallycross, and strict rules make things quite samey too. I've seen people talk about Rallycross like it's fucking Grasstrack oval racing, in fact I've seen the same people go "If you want to see a real mans sport, check out BTCC". FUCK knows what they've been watching, but it sounds like they've never seen Rallycross in their lives. If you haven't watched any before, go check some out on YouTube or something. 600bhp 700lbft 2ltr flame throwing anti-lagged 4wd turbo cars door to door, sideways everywhere, on a twisty track which is a mix of tarmac and gravel. As the races only last 5 laps (It was usually 2.5 laps in the 80s/90s), so unlike most racing, it doesn't have boring parts where they're trying to save the car, or tyres, or engine- It's flat out from the start to the end. Anyhow, as I love tuning (and presumably if you like Stav-Tech you love tuning too), the main reason I love Rallycross is the insane acceleration of these things, and that's because the engines are fucking MENTAL... In recent years engines in the top class are restricted to 2ltr (turbo, of course!) and with a 45mm inlet restrictor, which keeps power back to around 600bhp and 700lbft of torque, though previously there was no restrictor as such, but instead different minimum weight classes depending on engine capacity. Things did vary country to country, year to year, but for example, in the late 80s early 90s in the UK, the 4ltr class, which mostly consisted of 2.3ltr turbo engine cars (turbo or supercharged meant a multiplication factor of 1.7, and 2.3x1.7 is a touch under 4ltr), had a 1100kg minimum weight limit. Cars in this class were things like Will Gollop's Metro 6R4 which was the V6 de-stroked to 2.3ltr then twin turbos added, giving it 750-800bhp, and other similar crazyness, such as the 4wd Turbo E30 BMW M3 of Arild Martinsten which also had 750bhp+ Due to the various weight vs capacity classes, it was common to see 1.4ltr to 3ltr+ cars all in the same race, and due to the lighter weights and the fact almost everyone had BIG turbos fitted, everything was, just like it is now, fucking mental fast. You'd imagine maybe that everyone would be aiming for the 2.3ltr turbo engine for the maximum power, but this wasn't actually the case, as these were days before seriously effective ALS systems, so power was always a trade-off with lag, and also, when it boils down to it, on a slippery gravel surface with few straights there's not much grip or opportunity to use big power. It was often said that around 550bhp was the maximum usable power, and many ex-GrpB cars either stayed at, or were even de-stroked to around 1.8ltr, which was enough for their 550bhp power goal, but allowed them to be much lighter than the 2.3ltr turbo cars. Having said this, there were some cars with MUCH more power, 750bhp+, but if you watch old Rallycross videos on YouTube it was spectacular but unless they were in the lead it was very little use on the twisting tracks, and usually have about a 2second oppertunity of full power per lap! Here's a few older rallycross engines. I say a few, as despite the wonders of the internet, it's not a time machine, so despite some pics being uploaded from the 80s and early 90s, there are literally NO pics around of some of the greatest, wildest, and most interesting rallycross engines ever made. Gollops twin turbo 6R4 lump? Nope. Martinsetens F1 Turbo M3 lump? Nope. All the countless Group B 205 T16s, Delta S4s, Audis, etc made better than ever that ran in Rallycross? Nope. Unfortunately there's very few pics out there on internet land, which really annoys me, but here's a few... In the 80s Renault Gordini turbo engines (Which are, in essence, the Renault 5 GT Turbo engines, but with a better, crossflow, cylinder head), from 1.4 to 1.6ltr were popular and used in both Renault and Volvo rallycross cars, often pushing well over 350bhp, and as they were fitted to cars that weighed well under 900kg, it's fair to say they went like hell. Another mega successful and popular engine in the 80s and even 90s were turbo'd versions of Ford BDA lumps, often built by Zakspeed, from 1700cc upwards, and pushing out well in excess of 500bhp. Beetles were popular in 80s rallycross too, with all kinds of specs, including 4wd turbo versions, like this one that's still around to this day... Most interesting about this one is the engine, which is still a VW block, but as Rallycross rules allow any heads to be fitted, it's got Subaru heads... One thing I'd like to know, and I've yet to see pics or info confirming it, is turbo position on this Beetle. Going by what I can see, I'd say it's mounted inside the car, where the rear seats would normally be, which is pretty cool. In fact I 'think' you can just about see it through the hole in the bulkhead on this pic... Rallycross gave a new lease of life for the Group B cars after they were banned from rallying too, showing what they could have been like with more development, making them wilder than they ever were in rallying. Check out this Citroen BX4TC. They were rubbish in GrpB due to lack of development, a total disaster, but in rallycross it got it's chance to be as mad as it should've been, and they were fucking weapons... If you're wondering how batshit crazy fast these cars were, even in the mid 80s, check out this article from 1984. No it's not in English, but enough of it is written in words we understand to get the rough idea of the 1984 spec of Rallycross legend Matti Alamaki's Porsche rallycross car... So this is 1984, and this Porsche 930 has 4 wheel drive, a twin turbo 3.2ltr flat six pushing out 750bhp and 6200rpm, and weighs, well, 1130kg I think? Check out the old-skool timing gear wheel on the back in the main pic too! Now page two... 0-62mph in 3.1sec (so 3sec dead to 60mph), 0-100mph (160kmh) in 5.7sec, and 10.5sec quarter mile time. And this is 1984, 32 bloody years ago! EDIT!!! You might think the above acceleration sounds mad, and it is, but according to one of our helpful Finnish readers (who can read the above words, unlike me lol), those times were not only done in the WET, but the cars stop speed is 206kmh and hit it by just 260m, so did the last 140m just bouncing off the rev limiter in top, no more acceleration! So if it had the gearing for it, and a dry surface, that car is easily in the 2s to 60mph, 4s to 100mph, and running 9second quarter miles. In 1984, and not remotely a straight line drag car. Crazy shit right there. Rallycross is also where you see the engines that, while we all NOW know are massively tunable, have often been tuned to 600bhp+ for decades already. But as most people don't notice race engines, and just look at tuner cars for inspiration, people never realise. Like Saab lumps... Or the Opel/Vauxhall C20XE... Peugeot/Citroen XU... Rallycross is amazingly unknown by tuning fans in the UK, and to me I find that fucking bizarre, as frankly, the engines are THE most relatable to the shit they do of any motorsport; just usually way, way better. I mean, look at all these engines so far, they are ALL stuff you'd recognise from typical big power tuned engines we love to see in road/drift/timeattack cars, but frankly, these are usually done far far better, and cleverer, by people who know what they're doing rather than just pretend to. Not many parts on Rallycross engines are bits you recognize as the big money off the shelf tuner parts everyone likes to fit to their road cars though, as funnily enough, despite the hype, those bits are rarely, if ever, the best designs. That to me is a big reason why I love Rallycross- The engines are something I know, understand, relate to, agree with the design, and more to the point, they're my inspiration when tuning- Not some nobhead with a lockup who calls himself a tuner. THESE are the engines you should look up to in my eyes, not some shiny shit you see on FB, but more on this later... ANYHOW, moving on to the '00s to present day, Rallycross top classes around the world mostly changed to a 2ltr turbo class with an inlet restrictor (This was in 1997 if I remember right in Europe, and maybe 2003 in the UK?) to hold back power to vaguely sensible levels as things were getting ridiculous (and frankly, with today's tech, a 2.3 non-restricted turbo engine like the old days, would now have about 1200bhp, and costs would be fucking insane), though this 'vaguely sensible' level is still about 600bhp and 700lbft, which frankly is insane fast, like '0-60 in sub 2sec on tarmac' sort of fast. This is the usual 45mm turbo inlet restrictor fitted... Though at least once a twin turbo setup was attempted, which meant two smaller restrictors instead... One other big advantage the newer (and by that I mean in the last 15yr or so) engines have, despite less power than some of 80s ones, is fucking everything has something very noticeable fitted, usually a setup made Swedish company Tibuc... What the above is, well, the 2 blue hoses coming from the box on top of the plenum to the box after the throttles, is the electronic adjustable air bypass valve, a fucking big air bypass too, for the anti-lag system. And ALS is, if you speak to most Rallycross drivers these days, is THE most important part of the engine. The engine performance difference ALS makes is an incredibly hard thing to imagine unless you've experienced a really seriously good working system yourself, but the difference between it being on and off is like two different engines, and the difference between being competitive and not in Rallycross. Realistically, the 2ltr turbo engines of current cars, without ALS activated, are going to have a powerband of 4000rpm+ and not the most responsive things when on and off throttle either, as the turbos fitted are BIG. A small high rpm powerband and poor throttle response is NOT ideal for Rallycross, which is incredibly close and tight, on and off throttle constantly, and where a whole lot of the cars steering done with the gas pedal rather than the steering wheel. Basically, if you switch the ALS off on a Rallycross car they will get left for dead by the other cars with it active; you just can't compete without it. With ALS on (and Rallycross ALS is mental, like full boost all the time regardless of revs and throttle position style, proper fucking mental), the cars are totally different animals, like driving an 12ltr+ naturally aspirated engine that somehow also revs really high, rather than a typical 2ltr big turbo engine- Basically you get BIG torque and instant response constantly, regardless of revs. Some more pics, all with Tibuc ALS setups, as almost everything had/has it... As the above pics might hint, Cossie YB engines dominated Rallycross from the late 90s until recent years, as despite what the Jap fanboys etc like to think, if you wanted a 2ltr engine that could bash out 600bhp/700lbft and win you races, the YB was the one to have. How many SR20s have you seen in Rallycross? I can think of one tbf, in Finland, in a Mazda RX7.. But again, variety has always been key, I mean, here's a Mitsubishi 4G63... And here's a VW lump... Going bang up to date now to the present day, while the engines are the same principle, some of the ALS systems are even more advanced, more like mega power versions of current WRC engines, and now the airflow bypass isn't just past the throttles (though it usually is too, via fly-by-wire throttles now though more often than not), but it's direct in to the exhaust manifold via a valve and a series of pipes, which is more efficient. This particular ALS system isn't actually new though, the earliest versions of this were used on the Audi Group B rally car in the mid 80s. This ALS system is the valve at the front by the exhaust manifold on the below pics, and the small bore pipes from it is feeding air to each exhaust runner. Anyhow, regardless of age, the fundamentals of turbo Rallycross engines hasn't changed in 30odd years, and they're still fucking awesome and even the oldest ones should be the inspiration to most of us tuning turbo cars in my eyes.
I'm not saying copy them exactly, as I dunno about you but I sure as shit can't afford to build a 700bhp/700lbft 4cyl turbo crazy thing, but what I mean is check them out, check out what they do and often DON'T do, as you can be sure as shit they do or don't do it as they know what's best. Not sure what I mean? Well... For example, people often get all giddy and excited telling the world about their amazing boost pipe clamps that cost them about 50quid each, and those same people tell the world jubilee clips are shit and don't hold under high boost, etc etc, usually despite the person saying this having a car that don't even run a lot of boost. WELL, let's look at some Rallycross engines shall we? Money is NOT an issue for them, they are mega spec, the best of the best. The engines often run 3bar+ peak boost. But what holds the vast majority of their hoses on, from the early 80s to the present day? Yep, that's right, normal Jubilee clips. YES, shit twisty soft Chinese shit fake Jubilees are junk, but proper ones are strong as hell, can be done up mental tight, and hold a fuck sight better than most the wide Mikalor etc etc ones people like to shout about loudly on the internet. What about massive fuckoff inlet plenums like so many people pay big bucks for on their tuned road cars with barely 200bhp per litre? Well, these Rallycross cars are 300bhp/litre+ and do they have massive plenums? Fuck no, as there's nothing good to gain from it at all, and plenty to lose in response. A better than standard plenum? Yes. But IMO 80%+ of aftermarket plenums are just some badly designed, often oversized, shiney shit that does no good barring lighten your wallet. I've mentioned it in the past, but what about big cone filters in the engine bay? If you listen to internet car experts, they suck in hot air and kill ruin performance, seemingly oblivious to the fact ENOUGH air matters 100 times more than COLD air. Thankfully Rallycross people aren't keyboard tuners, and as the pics show, they put a massive air filter where ever it fits best. Oh, here's a good one you can see in these pics that everyone in the tuned road car world ignores, fucking TURBO HANGERS. On the internet you can't fail to read people constantly crying as their turbo manifold has cracked, or the bolts have worked loose, for the 20th time this month. What gets me is peoples solutions, or advice, are all kinds of crap, such as fancy bolts and fasteners, different exhaust designs, even fucking welding the turbo straight to the manifold like they're auditioning for fucking Roadkill or something. But despite all this, never do they have the sense to look at pretty much ANY proper race car and notice they fucking ALL run turbo hangers, taking the weight of that bloody turbo off the exhaust manifold, off the exhaust system, off the exhaust nuts, and bolts, and studs, and gaskets, and everything else that fucking breaks. And lo and behold this stops them breaking. Dunno if I ever mentioned it before on here, but on my old Cossie (they have a form of turbo hanger fitted as standard, nothing fancy, but they have them) I ran 2 years no issue at all without anything blowing, leaking, cracking, anything, despite 30psi boost, anti-lag, and serious abuse. THEN my turbo hanger got a bit tired looking so I removed it to sort it out, presuming it'd be fine without it for a bit (this was like 2002, I knew no better), and within a WEEK it was blowing at a join due to loose bolts, and from then on it would loosen bolts or blow an exhaust gasket within a few days of doing them back up. Refitted the hanger a week later and it never happened again. That taught me a lesson for sure, but despite telling people for about 15 years since that their issues would be solved with a turbo hanger, does anyone listen? Do they fuck, you still never see 'em. And the above are just a few examples of the many many many things just checking out some proper race car engines, and ignoring typical shitty tuner cars, will teach you. And ignoring teaching you anything, go watch some fucking Rallycross, it's mental! There's tons of 80s, 90s, and current Rallycross all over Youtube, and in fact, if you wanna see the craziness of modern ALS on Rallycross cars, find some vids of the Gymkhana Grid Championship finals in Greece from last weekend (ie end of October), there was various Rallycross cars in that, most notably Liam Doran's Citroen. The finals was at night, so it's flames galore, and by the end of a 1min run the entire exhaust, right to both tailpipes, was glowing red hot- Properly amazing looking. So yeah, Rallycross is awesome, and Rallycross engines are surprisingly educational AND awesome. Check them out... AYRTON SENNA'S FIRST F1 ENGINE- THE HART 415T. TINY ENGINE, TINY BUDGET, BIG TURBO, BIG POWER!10/19/2016
Brian Hart isn't a name many know of these days, but from the 70s to the 90s he was a bit of a legend in the UK tuning world, especially the Ford world, and this feature is about the wildest engine he and his small company produced, the Hart 415T. While Cosworth famously initially produced the legendary Ford BDA engine, what most don't realise is that is was Brian Hart that made is the success it was, producing the 2ltr BDG version that dominated the World Rally Championship (and practically every other rally worldwide) in the 1970s, and it was also him who developed the full crazy Group B rally version of the RS200 BDT engine, the BDT-E. Anyhow, what was known in the Ford Motorsport world as the BDG was initially developed by Brian Hart as a Formula 2 engine, firstly as the 420S, then in full developed, kick ass, practically nothing left of the original BDA (not even the block) version, as the 420R. Hugely powerful for it's size and weight, and there's versions right up to 3ltr that's been made, and still are to this very day. The Hart 420 kicked ass Formula 2 from 1976 on, and it was so good that the Toleman F2 team agreed in 1978 to help finance development, which clearly worked, with the engine taking Toleman to a 1-2 in the 1980 championship. And this is where shiz gets interesting, as for 1981 Toleman decided to step it up a notch, and despite being a small team vs the big manufacturers, they decided to enter Formula One, which by now allowed either three litre naturally aspirated engines (the Cosworth DFV still powered most F1 cars by then, though Alfa and Matra both had versions too- 14 out of the 17 teams used non-turbo engines), or 1.5ltr turbo engines, which Renault, Ferrari, and Toleman chose to use in 1981. As Brian Hart showed his amazing talent for mental 4cyls, it was decided that was going to be the new format for their 1981 F1 1.5ltr Turbo engine. Bear in mind this is a small team, and a small tuner, producing his own engine from scratch, to compete against engines built by some of the biggest companies in the world. A serious David vs Goliath battle, it seems and insane plan, but they did it... The Hart 415T engine looked similar to the 420R, and they were both 4cylinder 16valve engines, but the 415T was another ground up development by Hart, a 1.5ltr purpose built turbo engine that was actually a monobloc, ie the head and block are cast as one piece- No head join = No head gasket to blow! According to an old issue of MotorSport magazine at least, until this engine Hart had never seen a turbo in the flesh, didn't understand intercooling (might explain the chargecooler- reality>theory!), and the original 1981 engines were NOT monobloc either, though how true that is I don't know (Maybe just test engines weren't mono? that'd make more sense, but I've not found that info out). Unfortunately, as with all this old F1 Turbo stuff, most the truth is lost because of both secrets and age... Anyhow, here's some bare engine pics you can click on to check out the construction of this all-alloy monobloc lump. Note no head to block join, 4x throttle bodies, and individual external water ports above and below each exhaust port. The 1981 and 1982 seasons used a single Garrett (I've heard KKK mentioned too, but never confirmed this to be true) turbocharger mounted on top of the engine, and an alloy chargecooler under the inlet manifold to help keep temps down. Here's a 1981 engine, which made a touch under 600bhp in the race, and I think 700odd in qualifying... This is a 1982 engine I'm fairly sure, much the same basic setup, but a nicer manifold, especially for the wastegate take offs. These were also, as per all F1 Turbo engines of the era, a little more powerful than the previous year, as development progressed. Here's a few more early spec 415T pics showing the chargecooler etc, before we get to the big change and where things get really interesting... ANYHOW, the 415T engine so far, while getting a lot of praise for being a pretty amazing and strong engine considering it was developed from scratch by a very small UK firm with an absolutely tiny budget (in Formula 1 terms at least), it was still down on power versus the others, and while it often showed flashes of it's potential, the results so far didn't really materialize. With bigger sponsors and therefore bigger budgets appearing for 1983, the layout changed a little, with the engine looking a bit more conventional; a big intercooler, and the turbo mounted to the side on a long runner tubular manifold. Power was up, and the car overall was better, scoring points in the last 4 GPs of the 1983 season- Finally starting to show what this clearly very strong and capable engine can do. And then came 1984, and the appearance in Formula One for the first time ever, of the now legendary, and then reigning Formula Three champion, Ayrton Senna. Unfortunately things did NOT go well for Senna or his Toleman teammate in the first race of the season in Brazil, as BOTH cars retired with blown turbos, a problem that has always held the team back from the beginning, Senna after just 8 laps, his teammade Cecotto 10 laps later. Senna was pissed off, everyone was pissed off, but they had a solution, and rather than write it myself, here's it straight from one of the team... In yet another fantastic example of "Most famous names sure as fuck don't mean the best stuff", they fucked off the Garrett turbos that had held them back all these years, and went to the Holset turbos that they only really knew about due to their sponsor using them on their trucks. Holset knocked them up some suitable spec turbos in FOUR DAYS (More proof, if you need it, that the BS about 'truck turbos' not being made of the right materials for cars is bollocks- You think they magically fashioned them some stronger custom stuff in 4 days? Not possible. They were 100% off the shelf Holset parts), and lo and behold suddenly Toleman's unreliable turbo days were over. In fact, from what I understand, the one time a turbo did blow (unsure if it was 84 or 85), once inspected it turned out it was because a bit of valve seat (supposedly a weak point on these engines) went through it. These 1984 Holset boosted engines made 800bhp at 4bar boost, pretty insane for a 1.5ltr 4cyl engine, and while only about 50bhp down over the top cars at race boost, they were still around 200bhp down on the top cars at qualifying boost, simply as they didn't have the budget for special grenade-spec qualifying engines like some top teams did. Aside from that though, if it was BHP per £££ spent, they would've been the top by miles. These engines were 6.7:1 compression and revved to 11,000rpm in 1984. The actual Holset turbo used I'm unsure, but looking at pics, especially the compressor side and the compressor back plate, it looks to be a HX50 of some description. Unfortunately, despite the engine finally showing it's full potential in 1984, with 3 podium finishes for Senna, the following season didn't go well. While the engine was no longer an issue, Senna left for Lotus, and as the Toleman team had a habit of pissing off tyre manufacturers, first Goodyear, then Pirelli, meant they could only use Michelin, which massively backfired when Michelin withdrew from F1 after 1984 too, leaving them with no tyres at all for the start 1985. They missed the first three races due to having no tyres, and by the end of 1985 Benetton fully took over the team, which then became the works Renault team, and that was the end of the badass little Hart 415T engine. The last thing worth mentioning is the majority of the modern pics in this feature have been taken at Geoff Page Racing, who is pretty much the god of Group B and Formula 1 turbo engines, and looks after pretty much every legendary car from that era you can think of. I'd love to go there and do a feature on the place, as there a whole crapload I've yet to learn no doubt, but as yet it's never happened. Christ, if I could go back in time (this time armed with a decent camera) to about 2000-2001 when Joe Stevens from Bluesprint built my Cossie engine, I'd be able to show you some amazing F1 Turbo stuff- That place, both the actual workshop and warehouse, was full of BMW/Hart/Zakspeed/etc F1 turbo engines, manifolds, wastegates, all sorts, it was pretty incredible.
Anyhow, that's all I know, I wish I knew more, but it's a pretty amazing story considering how much of a (in F1 terms) shoestring budget they were on! In the UK and Europe, the Ford Pinto was about the most popular Ford engine to tune in the 70s, 80s, and early 90s, and to this day powers loads of fast road and race cars. The Pinto has spawned loads of legendary variations, most famously the YB Cosworth engine, but also things like the Millington Diamond engines you see powering most top Mk1/2 Escort rally cars these days, among other things. The thing is, while the Pinto was cheap and common, let's be honest, it wasn't that great, and didn't exactly set the tuning world on fire. Granted, it can be made to push out decent performance, and the bigger bucks and much rarer YB/Millington/Warrior/etc headed versions can be pretty insane, but for your average Joe road car tuner, once the 80s and 90s came along with various other, better, engine options, it just didn't cut the mustard; especially as there was very little serious turbo development done by tuners or racers on the basic 8 valve production Pinto engines. In the USA though, they didn't get 'our' Pinto, but oddly, and on a similar time scale to our engines (ie early 1970s on), they got a very similar looking, but it turns out totally and utterly un-interchangeable engine, fitted to a car that was called the Ford Pinto. But the engine wasn't called a Pinto, the engine was the Ford Lima. It looks like a Pinto, with it's inline 4cyl 8 valve setup and iron block and head, but the Lima is, aside from de-stroked race engines late small bore versions, 2.3ltr, 0.3ltr more than the biggest production Pinto, which is a bonus for tuning from the outset. In fact it's even more of a bonus than it first seems, as thanks to the engine design, the capacity can be increased hugely with stroker kits, with high revving engines up to 2.9ltr (just under 400bhp N/A!) have been built from the Lima. Standard capacity is one bonus, but another is, like it or not, the Lima block seems to be a lot stronger than the production Pinto block too. Normal Pinto blocks are generally considered a liability above 400bhp (though more has been done, with some risking pushing the 205 block YBs beyond 500...), and beyond that it's generally the stronger (but interchangeable) YB Cosworth (4wd and RS500) blocks that are needed for the Euro Pintos. The Lima block though? Well, 1000bhp+ has been known... Another massive advantage is the Lima attracted a huge tuning and motorsport scene in the USA and South America, so unlike the Pinto, there's a large amount of tuning knowledge and parts out there enabling BIG power; especially with turbocharging them. Perhaps the biggest single advantage though from a road car tuner point of view, is, from 1979 to 1989, it was sold as a factory turbocharged engine on a huge number of vehicles. This means it was not the lucky rich few who got to play with them, but your average Joe had no problem affording one, as they were cheap and relatively commonplace. As always with road car tuning though, there's always the question of "Where IS the limit of this engine?" and without motorsport it's rarely found out. But just like the YB Cosworth engine we all know and love, the turbo Lima was used by the Ford Motorsport teams for their race engines too, which meant a whole shitload of expensive R+D the road tuners could never do was done for them by Ford, advancing the tuning scene massively... In the early-mid 80s XR4TIs in the USA kicked quite a bit of ass in IMSA GTU racing using 2ltr 400bhp versions of these engine, still using the factory iron heads etc etc, but then for the TransAm race series where more many more mods were allowed, the Lima engine went fucking mental... Bashing out 800bhp (allegedly 1000bhp+ wasn't an issue in dyno testing, but of course it needs to last full race distance) from the little 2valve per cyl turbo engine, while still lasting full race distance, these things were mental. Check out the small water lines from the head next to each exhaust port- Cool little mod to prevent steam/heat pockets in the head, which is one of the many reasons big power turbo engines shit out head gaskets and so on... Even Ford themselves considered making the engine even better, funnily enough about the same time Ford Europe turned the Pinto in to the YB Cosworth, by creating a twin cam 16V Turbo version. While prototypes were fitted to a few testbed cars, inc a Mk1 Sierra chassis (the B+W pic below), it never saw full production, which is a shame, as potentially it was a Cossie beater when tuned, considering how good the 8V head version is... Anyhow, after Ford themselves stopped racing it, the tuning scene and indeed the racing scene using these engines went from strength to strength, especially with US Ford 4cyl tuning gods Esslinger Engineering producing countless parts for them, from stroker kits to lightweight, high flow, and strong as hell, alloy heads and blocks. It's not like these 8 valve engines are only good with a ton of boost shoved down them either, as they're hugely popular in naturally aspirated form in midget racing (crazy single seat dirt track go-kart things, not small people with large heads), and often push out 375bhp from 2.6ltr versions revving to around 10,000rpm! In fact Esslinger are so confident in these things, they sell a sealed crate race motor, 2.6ltr, 340bhp, and 9400rpm, that is capable of over 30 races before needing a rebuild- Try that with a Pinto! So yeah, in my eyes at least, as much as the YB Cosworth is one of my, if not my favourite engine ever, it's a real shame Ford USA and Ford Europe didn't work together on engines, as if the Lima existed over here in place of our Pintos (woo, alternate future theories...), our tuning scene, especially the Ford tuning scene, probably would've been even more full of big power cars, and even earlier than it was...
A good few years ago I built a RB20 (2ltr 24V inline 6 with a stroke shorter than most 1ltr 4cyls) powered R32 Skyline with a Comp-R RS341 turbo from Compressor Racing, which was basically a slightly modified Holset HY35- A 600bhp turbo, but a fucking good one. I built the R32 purely as everyone liked to say RB20s are shit, don't make power, etc etc, plus the fact everyone thinks a 600bhp turbo won't spool well at all on a 2ltr; especially not on a super short stroke engine like a RB20. I did it to prove a point really, and I did, making a dyno proven 470bhp on a standard head and cams, making some boost below 3k, full boost by 4k, and making big power to 8k+. The mapper said with mild cams and more boost, 550bhp was highly likely even on pump fuel. The thing was a fucking weapon and reliable too, in fact it's still running the same engine and turbo to this day, about 4 years later. There's a couple of pics below, and a fair few vids on my YouTube channel... Anyhow, a big kickstart to the R32 project was the fact that Chris who owns Compressor Racing offered me the RS341 as a test/development turbo, for next to nothing (in turbo terms anyhow, a couple hundred quid), to prove what the turbo could do, and it's fair to say I jumped at the chance and proved it nicely. Fast forward to now, and one of my current projects is a Renault 5 GT Turbo Raider. I fucking love them, they were my 1st n 2nd cars when I passed my driving test, and despite all the mental cars I've owned, they're still one of my fave cars as they're mad fun. For the last year or so I've been helping a mate spec/build his one, and the result is fucking awesome. 230bhp, revving to 7.5k, totally reliable on standard internals, and as it weighs nothing it's plenty faster than stuff like E46 M3s etc etc. But the main thing I like about them is the driving experience- Being a tiny light thing it feels 10 times faster and more fun than similar performance in a 'normal' car, and that's why I do cars- TO BE FUN TO DRIVE. Anyhow, despite shit tuners and retarded owners over the years giving them a bad rep for being unreliable, in reality the GTT C1J engines are strong as fuck when done right. Honestly. I promise! So the other week, despite having a totally different plan until then, I decided it's time to fit a man size turbo to one. I happened to have a pretty big spec GTT engine sitting in the shed waiting to be used, and like history repeating itself, Compressor Racing just brought out another new turbo, a Holset HX32 based turbo, which ticked the box as ideal for the big turbo I wanted (it's about Garrett GT30 size- 500bhp max). This time it was me making him an offer, and we agreed, considering all the good exposure my RS341 exploits got him, that I'd buy a turbo off him for a good price in exchange for a no-bullshit writeup on what I'm doing, plus some fitting/tuning info on Holset stuff in general (I get asked on an almost daily basis stuff on Holsets on tuned cars, I seem to have ended up with some kind of 'Holset guru' rep), so here it is... The turbo in question is THIS thing, their version of one of the 'Holy Grail' (ie fucking impossible to get) Holsets, a HX32. A HX32 is, basically, a HX35 sized compressor mated to a HX30 turbine wheel, which makes for a 400-500bhp capable turbo that spools like fuck, and is very highly rated by all of the lucky few that have got to use them. They come in a variety of specs, but what got me deciding I was gonna use one on my GTT is the fact this one has a 7cm (about A/R 0.50) T2 (T25, T28, whatever) turbine housing, which, in my experienced guestimation, I think won't spool up much/any worse than the 0.63 A/R GT28R on my friends GTT, but a whole shitload more power potential. Yesterday, the first thing I did once I had it, was do a mock up on my original/standard engine to see what needed doing, and once it's all laid out I'll take this engine out, put the fancy one in, and make some serious boost... So far so good, fits very nicely, looks fucking mega, and even my elbow/downpipe (from a Cummins engine, and I found it in my shed at home) fits perfectly, despite being 3.5in ID at the far end! Not sure where I'll route the wastegate pipe, but that's no issue. I'm gonna make a 3in (probably) custom side exit for the thing, but it's a shame it's not a drag car (and we live in a country that rains a lot), or I'd fit this straight out the bonnet, as it fits perfectly, and is fucking mega- An Inconel exhaust from a Cosworth engine Indy Car! Anyhow, back to the turbo setup- Here it is off the car. Basically I'm gonna be using the standard exhaust manifold (which is very good, 320bhp+ proven), a spacer/adapter to run a Turbosmart external wastegate, then the HX32 turbo, then finally a 2.5-3.5in cast elbow/downpipe which is a straight fit and makes my life easier as I don't have to fab one up from scratch now... The original plan (until I found the downpipe in the shed!) was to make my own downpipe, as a normal 2.5in V-band setup like you can find on eBay fits just fine. Barely 1mm out all round, but the wonders of v-bands means that's no stopping a seal- I've been about 5mm all round before and no issue sealing. Here's some pics with the 2.5in v-band clamp... Another thing that I needed to do, and something most people need to do when fitting turbos, but SO many people don't seem to realise they can, is to clock (ie rotate) the housings to suit the application. Almost all turbos you can rotate the housings 360deg to suit the application, and that's exactly what I had to do for the GTT, so to bits it came, a simple v-band type clamp for the turbine, and the typical Holset circlip for the compressor. Here's the first "Stav's Holset Tech Tip" for you actually- Compressor housing circlips! They are pretty fucking beefy as circlips go, so can be a struggle to remove, and some people find IMPOSSIBLE to refit, with the grips slipping off over and over again, but I've done SO many over the years I can usually do them first time, and here's how... First up, Molegrips are the tool to use, bigger the better, and ideally with a curved 'mouth' part, lessening the odds of them slipping off. Removal with them is usually pretty easy- Do up the molegrips to as tight as you can possibly fit them, then use the strength of He-Man to squeeze 'em shut, and that's usually enough to remove the circlip. Refitting it is a bit of a bastard though, but here's how... Yep, TWO sets of molegrips! Again, get the grips around the circlip as tight as you possibly can, but unless you're Superman there's no way that's enough that when you close them the circlip is compressed enough- Not even close. Instead, attach a 2nd molegrip tightly to the adjuster, and use that to (carefully!) wind the circlips closed with that (you've got no hope by hand unless you've a massive adjuster knob on yours), and THEN when you close them up, the circlip is fully compressed, and hey presto, job done. Oh, here's a mini-tip for you too- Keep the bloody plastic dust covers that come on the turbo, don't just bin them- They're fucking mega handy to stop shit getting in your turbo when you're mocking stuff up etc... The next issue is this turbo is INTERNAL WASTEGATE, and I wanted to run an EXTERNAL WASTEGATE. That's a big problem, right? Well, people seem to think it is, see loads of people go "I want to run that turbo, but I can't as it's internal gate) but it's not, at all, it's sorted in 5min by welding the fucker shut. Just like pretty much every Holset I've ever seen, the internal wastegate isn't that big, even Compressor Racing state they'd highly recommend external gate if using on a spark ignition engine, and considering the amount of people running Garrett GT2871s and GT30s with internal gates and serious boost creep issues, I wasn't taking the risk of trying it, and an external gate is a better design from a performance point of view anyhow. So, how do you do it? Well I've seen some people run a solid bar instead of the actuator, locking the wastegate arm shut, but I don't really see the point of that, so I do what 99% of people seem to do- Turn the MIG welder up to full blast, and BZZZZZZZZZZT. Yep, just make sure the wastegate flap is fully CLOSED (yep, seen some weld it without it being fully shut, then wonder why their turbo's laggy!), and weld the fucker in place. You could cut/grind the arm down too to make it look prettier, but I've left it for now as might use it as part of a turbo hanger to support the weight of the turbo when fitted. FINALLY, and another question I'm always asked about HX35s, HY35s, HX32s, HX40s, and everything else (think even HX55s are the same? I forget now), the bloody compressor outlet flange! Rather than a normal slip-on, it's a fancy v-band on most Holsets, so your options are, find what the fuck fits to it, or the most common solutions of grinding it down a little and using a normal hose on it, or TIG welding your own chosen fitting to it instead. Both of those solutions are easy enough, but you could make something fit, or indeed fit the proper thing. While the ID of the flange is 2in, it's bigger than a typical 2in v-band, and you need a 2.25in v-band and clamp to fit to it, but they do, nicely. BUT the ideal thing to do is just buy the right thing like they had from the factory, and that's this... That's the normal Cummins compressor outlet pipe, same thing fits 99% of Holsets with that v-band outlet. And is a 90deg bend ending in a 3in slip-on hose fitting. Ideal. Part number is as you see on it- 3918685. I think it's about £70 from Cummins mind, so prob cheaper just to mod it as above...! Oh yeah, here's another thing I'm always asked- Holset oil feed and returns. Feed is 12x1.5 thread, don't need a restrictor unless you got mental high oil pressure, but use a -3 line rather than bigger. Return is IMPORTANT! Almost anyone who cries about their Holset smoking has usually fitted some pissy small return. It needs to be like 19mm ID bare MINIMUM, ie huge. Even most so called 'huge -12 fittings' on eBay have ID of about 12mm, so nowhere near enough. Fuck the fancy fittings, a plain, but large bore pipe is all you need. AND THAT'S IT FOR NOW, I'LL UPDATE ONCE I'VE DONE ENOUGH NEW STUFF, THOUGH MINOR UPDATES WILL BE ON MY INSTAGRAM, HERE.
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Hi, I'm Stav...You may or may not have heard of me, but I've spent the last 20 years working full-time in the tuning scene, and the last decade or so writing for various car magazines. Archives
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