FWD handling

[GZE016]

Hi Guys, i know i might be considered the enemy here coz i drive a Toyota but i’ve come to the home of FWD’s for some handling advice.

Looking for some advice on setting up a fwd for club sprints, car is a 90mdl Corolla with a 4AGZE engine (supercharged import) and lsd gearbox which makes it quite heavy up front with 65% of its weight there. Suspension is coil over with 355lb/in springs in the front and 250lb/in in the rear with koni yellow shocks, whiteline swaybar in the rear on the hardest setting and no swaybar up front on the advice of a guy who races a corolla in an IPRA series. Alignment settings – 3deg neg camber on the front with 2mm toe out and 1.5deg on the rear with 1mm toe out.

Car handles well and is predictable but pushes through the tighter corners so i suppose i’m looking for a bit more steer from the rear.

[quangsuke]

rear bushings would always be the most noticeable, rear struts to make it more stiff and responsive.

[GZE016]

Nolathane used front and rear and rear shocks have been revalved to suit harder springs, i usually wind them up to the hardest setting.

[quangsuke]

could weld in a cage to stiffen up the car aswell as safety =D

[GZE016]

probably a good idea

[chargeR]

What tyres are you using? What is the suspension architecture like on one of those corollas? Strut front and multi link or beam rear I am guessing? I feel like you could get away with a lot more rear spring rate and possibly use staggered tyre sizes to get it to turn a bit better and then perhaps use a wing if it is too oversteery at high speed.

Did you try it with the front bar still on? Is it possible that in the slow speed stuff you are rolling into positive camber at the outside front which is resulting in your understeer.

[GZE016]

Tyres are Toyo R888 and suspension is strut front and multi link on the rear.

Someone else has suggested a higher spring rate in the rear, does that sound right?

Sit's flater with the front bar on but also get more push.

3 deg neg camber and about 4 deg caster so i doubt i'm rolling into positive camber, also scuffing the tyres evenly across the face.

[chargeR]

Tyres are Toyo R888 and suspension is strut front and multi link on the rear.

Someone else has suggested a higher spring rate in the rear, does that sound right?

Sit's flater with the front bar on but also get more push.

3 deg neg camber and about 4 deg caster so i doubt i'm rolling into positive camber, also scuffing the tyres evenly across the face.

More rear spring would be a start I think and perhaps fiddle with the alignment a bit. Given that you have a Macpherson strut at the front with a motion ratio of around 0.9 or more and the rear multi-link will probably have a motion ratio significantly lower, perhaps 0.7 or less, your spring rates are probably fairly front stiff at the moment even with the larger rear anti-roll bar. Not sure what other advice to give, perhaps trade the car for something rear wheel drive? :p