I have heard that the S4 (V-8's) has a bit of an understeer. I'm not super savvy in cars so I would be interested to hear what is the best way to fix the understeer in these cars. I searched for the topic and could not find anything.

Do you consider the understeer to be a major issue or only under certain driving conditions?

Thanks.

 

Just generally speaking you can reduce understeer by doing anything that makes the weight have a tendency to shift to the front (thereby biasing grip loss to the rear). You can do this with stiffer rear spring rate or rear sway bar, for example.

 

nearly all cars come from the factory with designed mild (some more mild than others) understeer as it is safer than a car that oversteers...unless you notice it plowing through corners or you are going to track it, I wouldn't worry about it...you can increase front tire pressure by 2.5 pds or reduce tire pressure in the rear 2.5pds and reduce understeer but only slightly

 

IMHO, the understeer sucks in the S4. It is it's biggest downfall. But it's an easy fix.

Do what a lot of people do. Buy a new rear sway bar. The one from the RS4 ($250) bolts right on and will change the handling dynamic for the better. Just be careful because oversteer is a lot trickier to deal with than understeer.

 

Get the shims for the Quattro AWD to send power 80% rear.

 

No. The RS4 already has this increased bias.

 

Are you sure hotsauce? I could've sworn that only the R8 had 80% bias. Stasis Engineering is where you can find this.

 

Voids the warranty...

 

Does adding the rear sway bar create a oversteer or pretty neutral? Thanks.

 

Well the handling is relatively neutral (unlike say a Camaro = Consistant Oversteer or a Honda Accord = Consistant Understeer), but when you push it the car hard it will oversteer rather than understeer. You're just shifting the limit to the other side. Rather than have the nose push out, the tail will get loose.

Off throttle oversteer (backing off the throttle mid corner, and having the tail step out) will become more noticeable in high speed corners, but there shouldn't be a whole lot of that in every day street driving.

 

Thanks, that helps.

So is the rear sway bar something you think is a must on the S4 for a daily driver as I do not plan on taking it to the track. It sounds like a cheap modification and one that enhances the driving.

 

You don't "have to" but for the cost it validates itself in my driving experience. $250 is a cheap fix... And it's OEM parts.