Welcome to my world, my world of turbos, tyre smoke, and tuning...
Tuning cars, driving cars, testing parts, and complaining about everything. It's my job, and a the majority of my non-work life too...
IF you're going to take influence from something when tuning your own engine, I always say don't just copy other tuned road cars, or even tuners demo cars, as they're usually massively flawed, no matter how quick and expensive- Take influence from race cars. When I mean race cars I don't mean just some random persons race car, I mean world class, best there is, race cars. They've got the best budgets, and the best people, so if they're doing something, and it's not JUST because the rules say so, it's fair to say it's good, and it's strong.
The problem is, most modern stuff is shrouded in secrecy, is heavily restricted by rules and regs, or is so out there that it's just not relatable to our own tuned cars.
So what do you do? Well I go back in time a bit. While electronics and so on have improved, the basic principles of tuning are still the same as the 80s, and 90s, in fact there's a lot of stuff from the 70s that's fucking genius compared to what we think of 'top' tuned engines these days, 40 odd years later.
This is still a big issue, as a lot of old race technology was just as secret back then, so nobody ever knew, and by the time it wasn't such a secret everyone had forgotten about it, so the true details are next to impossible to find on paper, but luckily, we have EYES and the internet has PICTURES, and those my friends, are able to put words in our brains, we call them thoughts and ideas and plans.
As any of you who've read my shiz before probably know, I love turbos, and boost, and anti-lag, and frankly anything to do with turbos, and for that reason, despite there being not much legit detail about them, and having zero interest in later N/A ones, I LOVE the Formula One Turbo engines of the late 70s and early 80s.
These engines were totally ground breaking, "inventing" and using many turbocharging methods that are even today only ever used in "Groundbreaking" turbocharged cars, well over thirty years later, and many that were used would be slated in a "WTF, that won't work" way by the typical internet bedroom tuners of today if they saw someones project car with it on, despite it being technology twice as old as some of these dickheads are.
ANYHOW, because of this, I've decided to do occasional features on certain mental turbo race car engines from back in the day (F1, GroupB, Rallycross, IMSA, and so on), as they are often VERY relevant to today's tuning, the info out there is practically zero, and frankly, they're cool as fuck.
What this WILL be though is me explaining what I see via pics etc, as almost none of the stuff I'll talk about is mentioned anywhere on these old F1 pages with engine details etc, which is a shame, as these mental engines are never done any justice due to this- They just talk about power and boost and that's it.
The one I'm going to start with certainly isn't the most famous or sucessful, but it's one of the most oddball, coolest, and most changed over the years, the Ferrari twin turbo V6 from the 126 series of F1 cars...
Right from the start of it's life in 1981, it was a 1496cc 24V V6, which had a tiny stroke of just 48mm. That's really small as these things were built to REV and make POWER rather than potter around at low rpm- A typical production 1.4-1.6ltr engine tends to have a stroke somewhere between 75 and 90mm.
Compression Ratio was LOW, about 6.5:1, despite running the most det-resistant fuels known to man, plus water injection, massive intercoolers, and more, and for a good reason too- to get BIG bhp per litre you need BOOST- These ran, at their peak, over 3bar (~45psi) in race trim (~660bhp), and over 4bar (~60psi) for batshit crazy qualifying 850bhp mode.
This is the equivalent of a 2ltr engine pushing out over 1100bhp (qualifying) or 880bhp (race trim), and to lasting not just a couple of hard laps, a quick squirt up the street, or 8seconds up a drag strip, which is enough for most tuned road cars today to crap their pants, but 1.5 to 2 hours fucking flat out pedal to the metal full revs full boost full anti-lag racing. People can argue about this all day long, but you think even with modern ECUs and sensors you'll easily get an engine with that much bhp/litre lasting 2hr flat to the mat at 9.5/10.5/11.5:1? I don't. A lot of mappers can't keep engines together running 1.5bar and 8.5:1...
Anyhow, on to the cool shit you can see in pics...
First up, as above, at first the thing wasn't even turbocharged! It was "Sort of" supercharged, and what I mean by "Sort of" is it ran a Brown Boveri Comprex Pressure Wave supercharger. Those things are very odd, like a mix between a turbo and a supercharger, but in fact neither. They're rare, and a bit flawed, but very cool. The Wikipedia page about them is HERE. It was only tested like this, in 1981, and never raced, as you know what's better? TURBOS!
Despite the big deal about a few modern BMW and Mercedes Vee engines with the exhausts inside the Vee and the inlets on the outside, it's far from new, and this Ferrari engine ran like this, as the pic of a very early version above shows.
Twin KKK K26 (Possibly K27 compressor side) turbos, and a single, but fucking massive, external wastegate.
Note the pre-turbo throttles, which was a very early way of helping combat turbo lag (put your hand over the vacuum cleaner inlet and listen to the rpm increase, same thing...).
Also note the inlet plenum design, which is basic, but done in this cone shape as a way to equalise airflow- The furthest away cylinders get the MOST air in a boosted application, which is another reason all these aftermarket 'high flow' box/blob inlet plenums are shite.
Another pic from a fairly early version show the less then sexy, but clearly fine, air filters, but most interestingly, how the wastegate is pushed open- Not by boost pressure like 99% are these days, but by EXHAUST BACKPRESSURE!
(follow the pipe from the bottom port of the wastegate to the turbine housing inlet)
This is actually VERY clever, as pre-turbine backpressure is key to power and reliability, more so even in my eyes than the pressure everyone knows, boost pressure.
As the pic below shows, the wastegate was piped up in the usual twin port way, with a typical vac line going to the top feeding it boost, allowing boost pressure levels to be controlled easier. Also note, below pic is later spec with full EFI.
Next up on the "Blimey, how interesting" list, the intercooler inlets and outlets...
The pic above in an early engine, but the design stayed the same regardless, simple as it's a good idea, and that's equal flow inlet and outlet designs for the (massive) intercoolers. 99% of intercoolers you see have a 3in (or less) round inlet and outlet pipe, but that isn't making the most of the intercooler at all, in fact a lot of the size is wasted. Having it as above makes sure the airflow is spread right across, massively improving cooling for any given size cooler. (also note, yet another different inlet plenum, but still smaller at the far end).
Look at the bottom right of this late spec version of the engine at the inlet plenum design. This is the "Twin Plenum" or "Equal Flow Plenum" style, used by Audi since the Group B days right through to modern LeMans etc cars, and often seen in Rallycross, WRC, and some tuned road cars. A quick google will find you pictures of the internals, but it basically directs air through a long but narrow slot the length of the main plenum, which gives far, far, more equal flow per cylinder than a traditional inlet on a boosted engine.
The more equal airflow per cyl, the easier a car is to tune for maximum reliability as well as power, and overall makes for a more efficient engine too. A BIG reason a whole lot of tuned turbo road cars blow up is because the AFR sensor signal they tend to be tuned from is an average from all the cylinders, but some cylinders get a LOT more airflow than others due to the unequal flow, so some run much leaner and much hotter than others, so while the average AFR might be 11.5, some might be 10.5, some might be 13+, so those lean cylinders pop head gaskets and melt pistons...
YET AGAIN, the above is something pretty ignored in the tuning world, esp in the UK, and when me and Zurawski Motorsport designed one for my RB20 engine, I got no end of shit, fucking pages and pages of it, from internet tuning experts (ie never built a good car in their life) telling me the design is shit, won't work, restrictive, etc etc, totally oblivious to the fact it'd been used on some of the worlds best engines for the last 30+ years.
Lo and behold my engine spooled amazingly well for the turbo size, made fucking mega power for a RB20 of that spec, and most importantly, was stupidly, hugely, det-resistant compared to most- Even 2bar on pump fuel there was no sign of it...
Next up, my favourite turbo thing in the whole world, and something rarely ever mentioned until cars of the 1990s, ANTI-LAG! I've never seen any info on it, but the pics clearly show it...
The type of anti-lag (ALS) used wasn't the basic throttle bypass ALS used on tuned road cars, most 90s rally cars, and still very popular in rallycross, but the better, albeit more complex version where the air goes directly from compressor outlet to turbine inlet, as per WRC cars and other current high-end turbo racers, the later versions of the legendary Audi Group B car, plus late Celica GT4 rally cars, and later Mitsubishi Evo rally cars.
Amazingly, and I'm still not 100% how it was done, but even on early mechanically fuel injected engines (as above) it was used. The above engines aren't the only mechanically injected F1 Turbo engines that ran it (See upcoming features), but from what I've guestimated from the pics, the increased fueling needed when the ALS was operational even with mechanical injection (rather than EFI, where the ECU has control over the injectors) was done via Hobbs switches and other basic sensors.
You may be thinking "What the fuck on the above pic hints at anti-lag anyhow?" well, that's the T-piece just after the compressor outlet with the green hose on it that disappears under the air filters. Logically that can only be for 2 things, a dump valve, or the above form of ALS. I was 100% sure they didn't run dump valves, but still, I'd like to see more pics before I was sure it was for the ALS. Luckily, there's this pic...
While the mechanics are busy swapping turbos, you can once again see the green pipe, but most importantly, notice one exhaust pipe running forwards, between the compressor housings, to what looks like a clamp, then a valve. That is 101% only one thing, the ALS valve, that lets the fresh air from the compressor outlets in to the exhaust pre-turbine.
EDIT- In fact, to double confirm it, I found this pic too last night, fairly clearly showing the ALS valve between the two turbo inlet trumpets...
The above picture shows a late spec engine showing a good view of most of what we've talked about. The equal flow inlet plenums, the equal flow intercooler pipework, the anti-lag outlet pipe, and also note, as this is a late spec engine, it's running EFI with 2 injectors per cylinder.
Also, look at the temperature sensor stickers, measuring not only compressor outlet temp, but temp at each inlet port, showing not only how good the intercooler is, but will help indicate how equal the flow is too.
Intercooler is made by Behr, who are about the best intercooler makers in the world, and made the standard Sierra Cosworth intercoolers too, which are amazingly good for their size too.
On a related note, the ECU setups on these were Weber Marelli ones with Bosch injectors, just like Cosworths, Integrales, Ferrari F40s, and many other legendary 80s and 90s turbo cars.
Finally for above, can you spot something else different from earlier engines?
Yep, late engines seem to have a different head design, with 2 exhaust ports per cylinder, ie one per valve. Some, albeit not many, road car engines have this, such as the 1.9ltr 16V engine found in the Peugeot 405 Mi-16.
Anyhow, that's about it for this time. Hope it's not just me that finds these fucking mental old engines really interesting. I really do hope it's not just me, as if more people took their design influence from these there'd be a whole lot cooler and faster cars out there in 2016...
PS- Here's a couple more random pics of this mental (albeit nowhere near the best F1 Turbo engine of its era) motor...
Hi, I'm Stav...
You may or may not have heard of me, but I've spent the last 15 years working full-time in the tuning scene, and the last decade or so writing for various car magazines.