Touge Tuning Guide *Updated!*

Skinnier tires on the front help road FEEL and turn-in response, but that's more an issue in real life I've found. Unless it's to the extreme - you'll notice on the muscle cars that with their 255/305 combination in place, they tend to push very badly right from the gate. I have it easy though, I only need to apply tires to one end of my car.

Get the max tire width you can on both the front and the rear, it doesn't matter if it's unbalanced. I can't stress enough how important this is. The wider tires you have the better you're going to drive.

Me? As it is my rear tires barely hit temp - I actually got rid of the mildly wider rear tires I had for the stock width, dropped the PI to let me pick up 4 extra hp and drop several pounds. I see no upside to wide rear tires on a FWD car, and if there is, T10 needs to get their shit together big time for FM5.

T10 doesn't need to get any shit together.
If you don't see an upside to wide rear tires on FWD, then you don't understand FWDs well enough.

Tell that to the Touge/Auto-X/Time Attack drivers and builders who use 275-345 width front tires, poor schmucks have it all wrong.

We're talking about rear tire width, not front. The benefit comes in the suspension tuning. Tweaking the setup towards oversteer induces better turn-in and less understeer. The only way to keep a FWD car with an oversteer-inducing tune from actually oversteering is to have wide rear tires...

And this is Forza, not real life. I think the Auto-X guys are better off racing on actual tracks.

Well, that's what I mean - by keeping smaller rear tires, I not only keep PI for other areas, but that in itself INDUCES oversteer, so the rear suspension can be set with softer springs/shocks and a smaller bar, which in turn keeps the car from hopping over bumps.

BeamierMoth wrote:

Well, that's what I mean - by keeping smaller rear tires, I not only keep PI for other areas, but that in itself INDUCES oversteer, so the rear suspension can be set with softer springs/shocks and a smaller bar, which in turn keeps the car from hopping over bumps.

Well I do get what your saying

By not putting the bigger rear tires, you are sacrificing a little handling, but if you can control that, then you can put more power.

Bigger tires on the back may be beneficial to the handling, but overall, using the PI for power might have better results like what you use now. But I think from a pure handling aspect, bigger back tires could be better.

But I thought rear tires on FWDs don't even increase the PI?

They might, it depends on the car - Most FWDs with race tires are going to be limited by their front grip, and if that's the case, what do wider rear tires accomplish? Now yes, when I'm driving/tuning a car on street or sport tires, the rears are able to come up to temperature and aid with overall grip when set to the same width as the fronts - but with a 245 rear, for example, on my Koup, I'd have to set the rear suspension to "iron bars" for the tires to ever reach temp/be ready to slide if needed.

Now yes, on a car with very small stock tire widths, you're going to be adding at least SOME rear tire. The Kia already comes equipped with 225's though - more than wide enough with slicks.

They do, Kraze - not much, but even 4 PI is a racing flywheel, or, in my case, street fuel tuning.

I'm not going to pretend I know what i'm talking about when it comes to FWD, but I can say without a doubt for AWD and RWD cars you're shooting yourself in the foot without the widest tires possible on both the front and rear.

Oh absolutely.

Does anybody know about Gear tuning?

You want 'em nice and short. Ideally, you want to be in 5th/6th gear on the straight and in 1st/2nd gear in the hairpins. But it's all preference really.

Thanks.

This is awesome. Thanks a lot peeps.

Yeaaah !! that's what i'm talking about

The only thing i wanted to find, thanks a lot for your work and keep going ^^

Thought i'd add that my earlier post about max tires size front and back in RWD and AWD doesn't exactly hold up anymore. I've used uphill setups on an FD with smaller front tire size that felt great and was faster than my old best time.

And I've done setups for the Supra and S2000 that have max front tire width but only moderately sized rear tires (either same size as the front or slightly wider) which makes room for more PI and doesn't sacrifice much grip at all.

This is the result of a good balance i think, if we look at the S2000 the front grip have a 225 or 235 size and rear 275

If i'm not wrong, when a car have too much grip in the rear at the acceleration it would loose grip in the front and make the car unstable when you suddently turn
For the S2000 with a spoiler and a full tire size the car suddently oversteer sometimes, i can't explain it but it's real, and it's sure that a good grip balance into the front and the rear could help to make the car more stable

If you're referring to me having a tire size offset with my S2000 tune then that's because the rear tires go to 265 but the front tires only go to 225. Since the S2K can't be fully upgraded while in B class you need to compromise with the tune. Because I'm running stock power (247hp) there is no need for 265s in the rear so I upgraded *most* everything and then slightly upped the rears to maybe 235 I think.

So it's not like that because big rear tires cause understeer, it's because they take up a lot of PI.

This guide helped me a lot. Been working on my FC all day and couldn't get the right setup going, read this and I just got my FC to break under a 50. Ran a 48 but hey, its a start. Loving the grippy feel I have going for this FC.

Question: with all the expert tuners on the union, guidelines and even tips for springs on a race suspension haven't been updated?

With a lets say 2000 lb car i wud set my spring rates between 420 and 350 in the front and 310 to 375 in the rear. The heavier the car the stiffer i make my springs the lighter the car the softer the springs