B8 Suspension woes... - The Unofficial BMW M5 Messageboard (m5board.com)

Adam · 28th November 2005, 14:01

Dear All,

My B8 handles like absolute rubbish at the moment

Its hard to describe it, but i would say that the steering wheel feels like it is connected to the wheels via rubber band. I ahve no confidence at high speed, the car kind of just wallows and reacts slowly.

I replaced the tyres in the front with Michelin PS2's 235/40's. Does anyone think this could cause the car to handle so badly? I then almost immediately took the car in for a service (drove 10miles or so) to the BMW dealership where they replaced shocks and bushes. Got the car back and then realized that there was something wrong. I immediately thought that the suspension settings were all out, not so, as i took the car to another dealer...and they said all was fine.

Should i replace the front tyres? What are the Alpina recommeded sizes? I know these are impossible to get, but perhaps i could source this size in continental sport contact 2's...

thanks for any help,

adam

DaveW · 28th November 2005, 16:04

Hello Adam,

First of all don't stress - unless you have some serious and previously unreported chassis damage, then all your problems can be solved!

Now, you mentioned this before in one of your mails, tyre pressures are very important and at this time of year when temperatures drop, it's entirely possible that tyre pressures need to be checked and altered.

Second - tracking. British Roads are awful and that's being polite. Just driving the Bi-Turbo along some sections of the M25 can make you feel like the front end is disconnected from the back - the wheel ruts caused by heavy lorries just grab the steered wheels and make the car move all over the place. That is however, because I have a very neutral steering setup with very little toe-in. Have your tracking checked and see if they can 'dial in' some stability.

Third - How are your bushes? If your pressures are ok, tracking is ok and BMW say nothing is falling off, how are the actual bushes at ride height? Most cars will sit differently while travelling at speed to when parked up and stationary - get the car checked at ride height - a geometry check at ride height will probably show up worn bushes as the measurements will 'move around' as the test progresses.

Other - Just a process of eliminating wear - streering uj's, steering component mounts etc.

Overall, I can't believe your B8 has a problem that is not going to be simple to fix - the hardest thing might be the diagnosis!

Cheers,

Dave.

Adam · 28th November 2005, 22:43

Dave,

Thank you very much for your informed answer

, much appreciated

all the best
adam

Stevie · 28th November 2005, 23:54

Quote:

Originally Posted by Adam

Dear All,

My B8 handles like absolute rubbish at the moment

Its hard to describe it, but i would say that the steering wheel feels like it is connected to the wheels via rubber band. I ahve no confidence at high speed, the car kind of just wallows and reacts slowly.

I replaced the tyres in the front with Michelin PS2's 235/40's. Does anyone think this could cause the car to handle so badly? I then almost immediately took the car in for a service (drove 10miles or so) to the BMW dealership where they replaced shocks and bushes. Got the car back and then realized that there was something wrong. I immediately thought that the suspension settings were all out, not so, as i took the car to another dealer...and they said all was fine.

Should i replace the front tyres? What are the Alpina recommeded sizes? I know these are impossible to get, but perhaps i could source this size in continental sport contact 2's...

thanks for any help,

adam

235/40 17 is the correct Alpina size for the fronts, only the rears are difficult to obtain. As for PS2, only a Rosso is on par, and don't even try a Conti. Definetly 2nd rate....

I'd check all bushes, or just replace them if you havent allready. If you want the front wheels kept in place better use new alloy "banana's" from an e30, they have one less rubber mounting. There are also some improvement available rubberwise, especially helpful if you're hard on brakes. Consider E30 M3 rubbers for to hold them, but press them in with the excentric hole facing downwards, or you'll lose too much steering-feedback with the big heavy motor up front. You won't mind the extra camber, but avoid the extra castor. That means turning it 90degrees from the e30-M3-intended fitment arrow.

As far as I can remember there was a huge thread about B8 suspension about a year ago, I'll see if I can find it for you.

Edit: Here you go: Brakes and Suspension for B8 4.6

m5 killer · 29th November 2005, 02:06

Quote:

Originally Posted by Stevie

235/40 17 is the correct Alpina size for the fronts, only the rears are difficult to obtain. As for PS2, only a Rosso is on par, and don't even try a Conti. Definetly 2nd rate....

I'd check all bushes, or just replace them if you havent allready. If you want the front wheels kept in place better use new alloy "banana's" from an e30, they have one less rubber mounting. There are also some improvement available rubberwise, especially helpful if you're hard on brakes. Consider E30 M3 rubbers for to hold them, but press them in with the excentric hole facing downwards, or you'll lose too much steering-feedback with the big heavy motor up front. You won't mind the extra camber, but avoid the extra castor. That means turning it 90degrees from the e30-M3-intended fitment arrow.

As far as I can remember there was a huge thread about B8 suspension about a year ago, I'll see if I can find it for you.

Edit: Here you go: Brakes and Suspension for B8 4.6

stevie i got you wrong on the contis mate they are way better than the ps2, im using them on the bi-turbo now and they are good.

Adam · 29th November 2005, 13:03

We run Conti sport contacts on most of our cars and they are really superb,

thanks for the input, really appreciated.

all the best
adam

m5 killer · 30th November 2005, 01:17

Quote:

Originally Posted by Adam

We run Conti sport contacts on most of our cars and they are really superb,

thanks for the input, really appreciated.

all the best
adam

adam if your having trouble with getting tyres, i can get you the b8 sizes in london.

BlackB8 · 1st December 2005, 23:50

Just as a note, the last time I changed to new tyres I did feel a difference at first from my old tyres - but this was mainly due to the fact that the old tyres were pretty worn and the new ones obviously had a couple of millimeters more tread. The feeling wasn't as strong as you described it but maybe in your case it is just a combination of a lot of things at the same time.

Cheers, Alex

by the way, did you also check your suspension in the rear (bushes, shocks, etc)

Adam · 2nd December 2005, 00:59

Yep suspension was checked alround, its really puzzling me, i have a quite a long motorway trip tomorrow, and will report back...

cheers for the heads up m5 killer too

all the best
adam

Tinker · 3rd December 2005, 16:38

Adam, soory to hear about the car.

From what you say you've changed all the bushes and tracked the car ... then can't see what is wrong ... does the steering wheel vibrate when braking/straight ahead?
Have you curbed a wheel?

As has been said before it is just the rears you can't get anymore (well you can in the UK, but they are no longer in production), I have been recomended by Alpina to put 245's on the rear, don't know if anyone has done this.