Suspension Set up

decoupe · Jun 30, 2011

One of the driver instructors that taught for BMW advanced school here took my car out for a drive - enlightening and lots of fun. He said the car was very nicely balanced for a street car but suggested that I try to reduce the oversteer that he described as predictable but correctable. He also said that unless I do address the understeer - I should not add more power with out a lot of track time to learn what to do with it.

Suggestions included any or all of: reduce air pressure in rear by a couple of psi, wider wheels (currently 16x8 rear), downforce and heavier front sway bar (currently 25mm front and 23mm). He did not recommend coil overs without a lot of chassis and cage work for fear of shaking the car apart (currently has ST lowering springs and HD shocks).

Ireland has a 28.8mm and 22.5mm set (much heavier bias in the front) which sound more like what the car "needs" for a street track set up without turning the ride into something too harsh (as in coilovers and sport shocks) so I'm inquiring if they will sell just the front. Otherwise I'll be selling what I have now to help offset the change.

Wondering what others have done or suggest - Essex brothers? What does the Pumpkin run?

Doug

shanon · Jun 30, 2011

Hi Doug,

Are you considering coming over to the 'dark side' ;-)

The Pumkin runs Ireland's coil-overs for the E9 with 550lbs springs up front with Bilstiens Sports with 500lbs springs in back. Urathane bushings everywhere. 19mm (?) Adjustable rear sway bar in back 22mm (?) up front. Don't remember exactly off hand, but all i need.

handling is awesome on track, HWYs & good tarmac, a bit harsh on crappy roads. You can always lower the spring rate (400-450lbs?) to reduce the harshness for crappy roads if you like and then put the stiffy's back in for the track.

You can read all about the set-up & ride in June 2010 issue of BIMMER magazine where my car was featured.

HTH,
-shanon

BarryG · Jun 30, 2011

Nice plug.. Shanon

I have Ground Control camber plates
Koni 2 way adj / 2.5" 440 lbs Eibach up front
Bilstein sports / 550 rear 8.5" hypercoil in rear

My next thing to do is ireland's sway bars. That should set me up just right.

The Dark side is a good place:twisted:

Barry

decoupe · Jun 30, 2011

With the heavy frost/winter expansion taking it's toll on the asphalt I think the sway bars would be the next step but good to know some starting points on the spring rates if coil overs become an option. That and the continued weight reduction program.

With respect to "dark side" I'm thinking of a trackable street car rather than the other way around. The nearest road course is an hour away, full of frost heaves and potholes, and will be shut down at the end of this season. A new one is just under construction near Edmonton which is 3+ hours but will be a much nicer facility.

Shannon - I saw the issue but will have to see if Bimmer has articles archived since it is long gone to recycle land. Quick ratio steering box - think I asked but can't remember your response.

Thanks,

Doug

shanon · Jul 1, 2011

Had a manual steering box as a paper weight for a long time. It went to a CSL.

Drove a buddies with a manual box conversion. I liked the space/weight saving concept but the car sure was a bear at low speeds/parking etc. Couldn't justify the hassle of the conversion. My brother and I raced/tracked with power steering, no complaints at all, BMW power steering is very good, and its easy on the arms for a big, heavy car (das boots!). Decided to well enough alone keep some civility for everyday life.

...and the ladies will appreciate it when you let them drive.

Probably the most cost effective go fast bit is a track LSD: 3:91 or 4:10. (I am not gonna get into track tires, those are amazing but are $$ consumables.) you won't loose your daily ride comfort but you can sure squirt outta the corners and down the straight! Swapping LSDs is fairly easy and straight forward (a couple hrs?)

have fun and post some tracks pics! Just arent enough E9s out on track.

decoupe · Jul 1, 2011

shanon said:
Drove a buddies with a manual box conversion. I liked the space/weight saving concept but the car sure was a bear at low speeds/parking etc. Couldn't justify the hassle of the conversion.

.

You can have the best of both world's - quick ratio and easy parking. I have a pdf of the install in a 2002 but can't attach it. It isn't cheap either.

http://www.ezpowersteering.nl/index.php?p=2

John Buchtenkirch · Jul 1, 2011

decoupe said:
One of the driver instructors that taught for BMW advanced school here took my car out for a drive - enlightening and lots of fun. He said the car was very nicely balanced for a street car but suggested that I try to reduce the oversteer that he described as predictable but correctable. He also said that unless I do address the understeer - I should not add more power with out a lot of track time to learn what to do with it.

Suggestions included any or all of: reduce air pressure in rear by a couple of psi, wider wheels (currently 16x8 rear), downforce and heavier front sway bar (currently 25mm front and 23mm). He did not recommend coil overs without a lot of chassis and cage work for fear of shaking the car apart (currently has ST lowering springs and HD shocks).

Ireland has a 28.8mm and 22.5mm set (much heavier bias in the front) which sound more like what the car "needs" for a street track set up without turning the ride into something too harsh (as in coilovers and sport shocks) so I'm inquiring if they will sell just the front. Otherwise I'll be selling what I have now to help offset the change.

Wondering what others have done or suggest - Essex brothers? What does the Pumpkin run?

Doug

Some drivers master and actually embrace oversteer, others not nearly as much. How many people remember the Sam Posey written story in “Road & Track” back in the seventies where Sam admitted to being shocked by how much Hans Stuck threw the tail out on his coupe in turns and he also admitted to not being able to keep up with him in his identical factory car ? ~ John Buchtenkirch

Suspension Set up

decoupe

(deceased)

shanon

Well-Known Member

BarryG

Well-Known Member

decoupe

(deceased)

shanon

Well-Known Member

decoupe

(deceased)

John Buchtenkirch

Well-Known Member