B8 A4 Allroad Understeer

[the_ace1982]

Hi folks, as much as I love the handling of my 2011 A4 Allroad I miss my old BMW and it got me thinking there must be an anti roll bar upgrade or similar to improve the understeer of these cars. I don't want to lower it, would be nice to reduce the understeer if possible

 

[desertstorm]

I have a 24mm H & R rear bar on my car and that certainly helps understeerr. The best bang for buck mod I ever made though was a home made front strut brace with a piece of aluminium box section and an hour of fettling. I suspect the A4 allroad may have the same L shaped piece of tin as my car had which does very little to stiffen the car.

 

[the_ace1982]

Interesting, did the strut bar help with understeer or just sharpen the steering up?

 

[spartacus68]

Darkside do RS4 rear anti-roll bar upgrade (22.5mm) for £180. https://www.darksidedevelopments.co...pgrade-kit-8k0511305s-8-x-bolts-2-x-nuts.html

 

[desertstorm]

Interesting, did the strut bar help with understeer or just sharpen the steering up?

It does both. If you fit a thicker ARB it reduces the maximum amount of grip at that end of the vechicle. So to reduce understeer you need to reduce rear end grip or push that the rear generates. Go too far and the car will be tail happy and potentially dangerous for people not expecting it. If you look at this video it's me in my car at Curbrough sprint course quite a few years ago now. You can see that occasionally the car is tail happy when provoked, and on acceleration you can get the rear breaking free a bit. This helps rotation and is a more interesting way to drive. The B8 quattro is a 60/40 torque split rear to front. The chirping noise from the exhaust was because of a mod I made to the DPF. Doesn't do that now.

 

[the_ace1982]

It does both. If you fit a thicker ARB it reduces the maximum amount of grip at that end of the vechicle. So to reduce understeer you need to reduce rear end grip or push that the rear generates. Go too far and the car will be tail happy and potentially dangerous for people not expecting it. If you look at this video it's me in my car at Curbrough sprint course quite a few years ago now. You can see that occasionally the car is tail happy when provoked, and on acceleration you can get the rear breaking free a bit. This helps rotation and is a more interesting way to drive. The B8 quattro is a 60/40 torque split rear to front. The chirping noise from the exhaust was because of a mod I made to the DPF. Doesn't do that now.

Awesome! I came from an M3 so i'm comfortable with oversteer and think this A4 would be massively improved with less understeer. do you have pics of your strut brace by any chance? I'm going to order an RS4 rear arb and book it in for a good setup at Automek

 

[the_ace1982]

Update, i've got an S Line rear arb ordered. Going to get that fitted along with a proper alignment set up and hopefully the understeer will be tamed to an extent at least!

 

[the_ace1982]

I've bought the darkside rs4 roll bar kit after the garage I had it in couldn't change the rear arb as they couldn't get the bolts out! Taking the car to Automek in east kilbride where i'm sure they won't have any such issue

 

[the_ace1982]

I have a 24mm H & R rear bar on my car and that certainly helps understeerr. The best bang for buck mod I ever made though was a home made front strut brace with a piece of aluminium box section and an hour of fettling. I suspect the A4 allroad may have the same L shaped piece of tin as my car had which does very little to stiffen the car.

Did you feel a difference in the ride qualiity after the 24mm arb was fitted?

 

[desertstorm]

Did you feel a difference in the ride qualiity after the 24mm arb was fitted?

No difference in the ride quality with the uprated rear bar.

 

[the_ace1982]

No difference in the ride quality with the uprated rear bar.

Awesome that was my only concern as my M3 was a good bit harsher with the uprated arbs on

 

[the_ace1982]

RS4 bar is on finally! Feels much better in corners and ride quality is still beautiful so i'm delighted with this mod!