R8 steering
Author
Discussion

moley78

Original Poster:

3 posts

216 months

Wednesday 29th October 2008
quotequote all
hi guys, just bought a used R8, wondering if some mild juddering of the steering is normal on full lock? any r8 drivers notice the same thing? almost feels like something is rubbing? apparently this is normal.

cheers

VAG1

784 posts

219 months

Wednesday 29th October 2008
quotequote all
yep thats normal. happens to a porsche cayman uswel. must be some sort of feature for some reason. oh and congrats on the purchase

Stig

11,823 posts

314 months

Wednesday 29th October 2008
quotequote all
Are you sitting comfortably?....

The "Ackerman Angle" allows the front wheels to turn by different amounts so that the tracks of the two front wheels are not the same. This allows the inner wheel to track at a smaller radius that the outer wheel. It is necessary to prevent excess tire scrub. The the car's "track" will mandate the amount of difference. In driving very tight "circles" it will become obvious. On a race course where `full lock" is rare it is not as critical.

Named after it's inventor Rudolf Ackerman, this angle defines the correct angle that steering wheels must have to effeciently negotiate a turn. In a standard turn, the wheel on the inside of the turning radius must follow a more severely curved line than the outside wheel. By setting steering arms, one can successfully adjust the turning angle so that the inside tire turns at a larger angle than the outside. This results in better traction around the turn.

Ackerman angle is the angle of the king post which holds the hub, the angle is the verical displacement of the top of the king post rearwards, the inside turning wheel will effectivly move in a smaller radius than the outside wheel, this angle also helps in the self centering of the steering in a straight line.

It was originally patented by Rudolph Ackerman in the late 1800's as a way to reduce the stresses on horse drawn wagon wheels which used a center pivot front axle. The stresses involved were responsible for premature breakage of the spoked wheels used at the front of the wagon.

Here endeth the lesson smile

VAG1

784 posts

219 months

Wednesday 29th October 2008
quotequote all
what he said^^^ haha

Dr G

15,987 posts

272 months

Thursday 30th October 2008
quotequote all
laugh

I did not know that!

moley78

Original Poster:

3 posts

216 months

Monday 3rd November 2008
quotequote all
wow stig, impressive. loving the car guys, its a beast. had some issues though. the brakes where constantly squeky, which i didnt notice at test drive. went back to audi 5 times, they suggested deglaze but eventually resorted to changing the front discs and pads and rear pads to get rid of it? how bizarre! it had only done 11k.

VAG1

784 posts

219 months

Tuesday 4th November 2008
quotequote all
i hope you didnt pay for that?

moley78

Original Poster:

3 posts

216 months

Tuesday 4th November 2008
quotequote all
no way, amazingly they did try and charge me initially though. a complaint to my dealer (maranello ferrari in egham) and the audi uk MD soon nipped that in the bud!