AU Falcon XR8 IRS Road/track setup

[atasr5]

Hi...

I have an AU Falcon XR8 series III V8 347 stroker with rear IRS. The cars suspension is stock and is mainly used for track days at wakefield, eastern creek and the dutton rally. I would like to improve the suspension, swaybars and lower the car. I also run proper tarmac tyres ie...yokohama AO48's and would like to greatly increase the front camber and whatever other suggestion you may have for better grip and turn in. This car is not generally a daily driver and was bought more for racing and motorkhana events. At the moment the front camber is set to 1.5 neg (thats its maximum) and the rear camber is 1.5 neg (can go to -2.5) . Whilst the standard suspension is fairly good for a stock car, she tends to lean hard on corners, gets nervous when switching from left to right when tackling close quarter turns, gets severe nose dip on hard braking, and the odd bit of understeer on the really tight stuff. The car weighs with me in it 1750kg's.

I would greatly appreciate any advice on suspenion setups, camber, castor, & toe setups. I'm well aware each track is different, but just need a ballpark guide to begin finetuning the car with a decent base to start from. Camber is most important to take full advantage of the tarmac tyres.


Cheers

[Wojtek]

Hi,

Firstly, I think you have a good base there being the IRS model with lots of potencial.

Due to your R'compund tyre choice and pure motorsport use, you really need fairly stiff suspension to match the tyres' grip levels. I am thinking of spring rates of around 500~700 lbs/in in the front and 300~500 lbs/in in the rear, with matching shocks and swaybars.

However, our lowering springs are rates at aproximately 350<>450 lbs/in (progressive) front and 290<>480 lbs/in (progressive) rear, but combined with sports rated shocks such as Koni Sports adjustables and uprated Whiteline swaybars 30mm adjustable front and 20mm adjustable rear, this package should still work very well for you.

You will also need a front camber and caster kit to be able to dial-in the correct settings. You shouldn't need to use more then -2.5 deg rear camber, so you don't need a kit there.

With respect to wheel alignment settings, I'd suggest that you start with -3.0deg front camber, max +ve caster, 0 or slight front toe-our, -2deg rear camber with ~ +1 rear toe-in per side. During your first test session, when you measure your tyre operating temperatures you will be able to fine-tune these settings much better.

Hope that this helps.

Cheers,
Wojtek.

[atasr5]

Hi mate....

Thank you very much for supplying that information. It has been very helpful.
Is their any chance you could list some part numbers for ordering. Or would it be better to simply come down to the shop for the guys to have a closer look.


Cheers

[Wojtek]

For a list of part numbers, best to check our catalogue. You can either use our Online Parts Catalogue, or download our complete catalogue from our website. If you're still not sure, check with our distributors.

Cheers,
Wojtek.