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...
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
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.