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 just want to smoke your tyres, do skids, burnouts, and powerslides, fuck yeah, have all the power you want and forget the rest, and that can be a whole lot of fun in a RWD car, mega fun.
But massive wheelspin in a FWD is pretty much super gay and not fun at all, and with 4wd your car is either insanely powerful or something's set up very wrong.
Fact is, if you want to actually go fast, it's about way more than just power, and a lot of people don't seem to be able to grasp that fact.
I'm not on about handling and stopping either, that's a whole different subject, I'm purely on about getting this power to the ground- Traction!
You see a lot of people, a hell of a lot of people unfortunately, really chuffed with their car, saying how 'fast' they are, as they smoke the tyres in 4th or whatever just by going full throttle.
But, err, if your car is wheelspinning, it's not going to be that fast until that stops, and in a lot of cases cars with half the power but decent traction will be leaving you for dead.
I'm not sure if these people truly believe their car is quick and have never actually raced or timed it to realise that their wheelspinning mess is actually nothing special, but practically everyone with a tractionless mess act like their cars are rapid when they're not.
One of the most common things you see is people really proud that their engine spools fast and smokes the tyres constantly, while also slating cars with with similar power but far less torque and low down power (due to bigger or no turbos, less capacity, more rpm, etc) as 'dogs' at lower rpm just because they haven't got a ton of torque.
But the fact is, thanks to the more sensible/usable torque levels they have for the amount of grip they have, these 'dogs' are often far faster in reality.
FWD and tuned diesel owners are worst for this, but grip affects almost everyone with big power on road tyres.
The bullshit talked about grip, or lack of, works the other way too, as the people constantly say FWD cars are useless with more than 200bhp/250bhp/300bhp (depends who you're talking to) are wrong as well.
Yes FWD is useless even at 200bhp with tons of torque, shit tyres, and an open diff, but even with 500bhp+ I've experienced road legal FWD cars that put all the power down from 2nd gear on, and with rear wheel drive cars you've got even less excuse to have no grip. Fuck, if you've got 4wd and big traction issues then you either need to sort your shit out or something is broke.
So yeah, having no traction means your is gonna accelerate slow no matter how powerful your engine is, and here's the various ways to help fix that...
The number one way to improve your traction is tyres. And as blatantly obvious as that is, people still ignore it, and I'd say there's far more big power cars on skinny normal road tyres wheelspinning everywhere, than ones running decent tyres and actually going fast.
The difference in traction under acceleration between the same size tyre, one a normal but decent brand road tyre, and one a road legal semi-slick, is massive.
I've experienced, many times, cars go from wheelspin in 4th with good 'normal' tyres to full traction most the time even in 2nd with a set of semi slicks of the same size.
This, providing there's no standing water, is actually the same in the wet too; it's only standing water when semi-slicks can be a bit crap.
People's reason/excuses for not running decent tyres like this is always stupid too; either that they're rubbish in the wet, which I don't really agree with anyhow, or that they don't last long, which is a false economy when they instead have a powerful car that's a complete waste of time and not actually very fast as it has no grip.
Tyre size is another big one- People rarely even fit the widest tyre they can get under their standard arches, never mind go as far as modify their arches to fit wider ones for decent traction.
This is also usually ridiculous as they end up spending ten times the money doing that will cost on other pointless upgrades. In fact it's that daft that people will fit the biggest wheels they can fit under the arches as they think it looks cool, but then fit way skinnier tyres just to help wheel fitment! You can't have it all, and what do you want? People to think your car looks cool, or for it to be as fast as you tell everyone it is?
Finally, tyre pressure- It can make a big difference to traction, and as long as your car isn't hugely heavy you can often run lower than the typical 30-35psi most people have theirs set at.
It's certainly worth looking at, especially as it's pretty much a free mod, and in drag use people often run barely 10psi depending on car and tyre type, and while this has an adverse effect on handling, on some lightweight cars some people still run under 20psi on the road and circuit, so it's worth some experimentation to see what suits you.
So many “Oh my God my car is soooo fast, my wheels are spinning in 9th gear” type people are wrong. Only one of their wheels are spinning, and their car isn't fast at all, as it's got an open diff or a really crap factory LSD.
Just like decent tyres, the massive difference a decent LSD makes to traction over an open diff is hard to imagine unless you experience it. It really is night and day, and in my book worth every penny. A hard used performance car with an open diff, even a pretty low power one, is not for me; I hate it.
There are lots of performance advantages of a decent LSD, but we're talking about getting your engines power down in this feature, and that's where a limited slip diff really is most obviously felt.
With an open diff power just goes to the wheel with the least grip, which means one wheel quite easily spins up while the other has no power going to it all, and the end result of that is no forward movement and just pretty much sitting there spinning one wheel like a dick.
With a decent LSD, power is forced to both wheels regardless of what has the most grip, which not only of course massively increases traction for that reason, but even WHEN the wheels are spinning, especially with a plate-style LSD, as both still have the power going to them rather than just one, there's still a lot more traction and therefore forward movement even when wheelspinning.
It's hard to imagine unless you've experienced it, but the amount of acceleration even when wheelspinning hard when you've got a good aftermarket limited slip (or locked/weldeds/spool) diff can be pretty incredible on some cars.
Please bear in mind though I saw a 'GOOD' LSD, as quite a few factory LSDs are barely better than being an open diff, especially once they get older, so don't just think because your car has a LSD as standard that it's effective- Often far from it!
YOUR SUSPENSION GEOMETRY
When it comes to getting power down, maximising tyre contact patch is key to making the most of what you have.
The most obvious factor here is to minimise camber on your driven wheels, BUT if you're really serious about putting the power to the floor it gets a bit more complex than that.
Most suspension designs have dynamic camber change, ie when your suspension lifts or squats, the camber angle changes. Some suspension designs change more drastically than others, so exactly how much you need to cater for this depends on your cars own setup, I can't advise you on exact numbers, but if you're serious about traction, you got to take this in to account.
Upon acceleration, a cars front end naturally lifts, generally reducing the camber angle of the front tyres, and the rear end squats, increasing the camber angle of the rear tyres. Because of this, on FWD cars a small amount of negative camber is often no bad thing as it can turn to zero camber as the front lifts slightly, and on RWD cars, zero camber, or even some positive camber, is often used on cars looking for maximum straight line grip, as this counteracts the natural negative camber increase that happens as the back end squats.
YOUR WEIGHT DISTRIBUTION
As mentioned in the geometry bit, when accelerating, the front lifts and the rear squats, and of course, you want to have as much weight over your driven wheels as possible, so why not do something about that?
Thanks to the rear end naturally squatting, RWD cars have it easier when it comes to grip, as the whole car is pushing down on the driven wheels, but regardless of this fact, moving any weight you have to the rear end is never a bad thing to help maximise acceleration grip; unless your car has so much rear end grip it instead does huge wheelies and tries to flip over that is...
On FWD cars the weight distribution issue can be much more important. The front end of a car naturally goes light upon acceleration, which is the last thing you want when it comes to grip, so anything you can do to keep weight over the front wheels the better.
Obviously this is no easy task, as you're limited to what you can fit under the bonnet, but this is why many FWD drag cars fit the fuel cell up front, and some people have even tilted the engine forward a little to help with the weight distribution.
Weight distribution is more than front and rear though- It's left to right, and this can have a major effect on traction due to how much force is put on each tyre. I've seen cars get major improvements in traction my making the corner weights over each driven wheel to be as equal as possible, therefore equalising their grip; to the extent some have said it was more effective than when they changed from an open diff to a LSD!
This is something which can be done by physically moving parts around the car, as well as small changes to ride height if you have coilovers. To even remotely accurately do this you need a set of corner weights, but this is something many tuning shops have and are more than happy to do for you.
While in general adding weight is never ideal, if traction is your main goal and you're still struggling with other methods, adding weight to the very front of a FWD car via thick metal undertrays or weights behind the front bumper, or to the very rear of a RWD car, either with weights behind the rear bumper or added to the boot, is sometimes done to push the driven tyres as hard in to the road/track surface as possible.
Finally, weight transfer from suspension movement. As I've explained, you need to keep the weight on the driven wheels as much as you can, and that generally means allowing a RWD car to squat the rear and lift the front, and conversely trying to prevent a FWD cars front end from lifting and the rear from squatting.
For FWD cars this tends to mean stiff rear suspension to help prevent squat, and various clever ways to prevent front suspension lift (which unfortunately depend on your stock suspension design, so I can't list them all here).
While jacked up rear ends are also sometimes popular, most the fastest FWD people tend to agree it's no big benefit, if at all.
For RWD cars they tend to want to allow the front to lift without lifting the wheels clean off the ground, and allowing the rear end to squat. A fairly soft rear end is a clear start point, and on the front things like soft and relatively long travel suspension, often with no anti-roll bar, allows the front end to naturally lift but also can help prevent the car lifting its wheels, which, while looking cool as hell, gives you zero steering, and potentially massive problems when you come back down to earth!
LIMITING YOUR TORQUE LEVELS
Last, but DEFFO not least, I'm going to talk like torque is a bad thing. As sometimes it is!
This is probably the most ignored factor when it comes to traction, as who'd want to willingly give up performance? Only a mad man, surely?
Well there's two things here. Despite the myth diesel and V8 owners like to loudly shout at every opportunity, torque doesn't really win races, and if you're spinning you ain't winning, so you're better off having less torque, so less wheelspin, but more acceleration.
This tactic is common on modern turbocharged drag and track cars, and is part of the reason so many are so fast and controllable in recent years, with things such as boost by gear (ie lower boost in lower gears), boost by speed (similar to boost by gear but works it out with speed) and boost by rpm (ie mapped to the boost rises slower and more progressively than they naturally could, to prevent a big spike of boost spinning the wheels), all easily configurable on a good ECU, as well as clever traction control systems that can limit wheelspin by slightly lowering torque when wheelspin is sensed without killing the power and slowing the car down like many factory systems.
The thing is though, while you may think these are pretty hi-tech and extreme tuning methods, this is actually way more normal and common than you many think. Many factory turbo cars, even some that are 25 years or more old, come with boost by gear or rpm as standard. Yes, many cars have it set, from the factory, that their boost pressure is lower in lower gears and/or rpm to reduce wheelspin, all controlled via the ECU and factory boost solenoid.
Even without clever ECU tricks like boost by gear or other traction control methods, a good engine spec and a good mapper can massively improve traction simply by creating an engine with a good power delivery.
Huge torque, or just sudden increases in torque, when you've not got the grip to use the aforementioned, is pointless and will prevent you reaching your performance goals, but are easily avoided.
A big part of the reason Prochargers and Rotrex units (ie centrifugal superchargers) are so popular among V8 drag racers and FWD track cars, is because of the linear power delivery they give, with no huge torque spikes to spin the wheels, and a very progressive increase in power all the way to the rev limiter, making for a tractable, controllable, and predictable car with massive peak power levels but far less wheespin than a typical car of the same power equipped with a positive displacement supercharger, nitrous, or a typical turbocharged setup, purely as they tend to give huge and peaky torque curves.
Other engine spec changes can help this too on traction-limited cars. Increased capacity rarely increases peak power, but certainly increases torque, so should be avoided if you're already struggling for grip. Small turbos at high boost means big torque and eaiser to drive, but a bigger turbo at lower boost for the same power can often give a better power delivery for a grip limited car, which is also kinder on the engine too. Using rpm to make power means less torque needed for any given power level, which again can actually be a useful thing if you're struggling for grip.
And that's it for now folks! Hope you've enjoyed this feature and found it useful, and of course show anyone else you know who may get a use out of it too.
I've actually got about 10 other features in progress right now, just, thanks to life getting in the way (I have some very kind Patreon donators, but the total is still very low so I certainly don't make a living doing this, or even close!), I've just not finished the others yet, but I do these at any opportunity I can, so please, watch this space!
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.