Need help on spring rates? quick?

[Mark]

Just ordered my suspension set up from Ground Control today for my '86 325. Jay told me that the 550lbs. front and 650lbs. rear are the way to go. I will be mainly running at Atlanta, Roebling and Daytona. I am sure I will be the minimum weight and am doing this for the first time so I have no idea. Anyway I saw some of your posts that said these rates were too high. Is this so and if it is what are you all useing?
Thanks, Mark

[zracer22]

STOP!!!! They recommended the exact same for me last year. They were too stiff. I just bought a second set from them, 450 front and 550 rear. I don't want to go any softer, because shocks may bottom out at 5" ride hieght. If the tracks you run are smooth as glass, 550 front 650 rear may be OK, but on a rougher surface, the rear end will skate all over in the corners.

[zracer22]

Mark,
Did you get the entire suspension package from Ground Control? What shocks?

[Mark]

So, do you recommend 450-550? Can I email you? I really need some help. Do you have I.M.? [email protected]

[zracer22]

Send me an email at [email protected]

[Mark]

I got the Koni shocks, camber plates, spring kits, rear schock mounts and the tabs for the M3 front sway bar. I hope I can catch him in time tomorrow. Do you think I should try to change or get some extra springs for the bumpier tracks?

[zracer22]

call me, I just emailed my number here at work I'll be here for another 5-10 minutes

[chuck baader]

mark, you mentioned the M3 front sway bar mounts..if you plan to adjust ride height to around 5", you need to shorten the front strut tube. to do this, you must mount the sway bar mount lower on the tube, which moves it too far from the sway bar. you end up with a cantilevered bolt to attach the linkage, and that is not rigid. bmp makes some neet sway bar mounts for the stock position that work very well. good racing

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Chuck Baader
SEDIV ITS #36
E30 BMW

[Oldmacd]

I thought that running M3 swaybar links and their respective attachment points was illegal on an E30. Is there something I am missing here?

Scott

[chuck baader]

i asked the question directly to svend pruitt and his iterpertation of the rule was that it was legal. moot point, although, see my last post.

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Chuck Baader
SEDIV ITS #36
E30 BMW

[James Clay]

I think the spring rates depend on whether your shocks can control the energy. Stock Bilsteins can't damp 500# springs effectively. Advanced Designs can, Konis may - Jay would know. We run over 1000 now on all the East coast tracks, including Sebring and Roebling, times are faster than the rates previously (about 500). We use the AD shocks.

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James Clay
http://www.bimmerworld.com
Engineered BMW Performance
BMWCCA/SCCA Racecar Rental
Genuine OEM and Used BMW Parts
(540) 639-9648
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[BMW e30 racer]

I am currently building my 87 325is car for ITS racing/daily driver. I did not want to spend the time to convert the strut to go the ground control route. So I chose TMS race springs that are 680# in front and 1026# in rear. I don't see how 550-650 could be to stiff as my car is driven on the street with this set-up. From what I've read about chassis tuning the spring rates they recommend to you would cause horrible understeer

[zracer22]

1026# on the rear at Nelson's, you would have to brake and downshift just to get throught the kink without feeling like a Frisbee sliding accross a concrete parking lot. All I know is that the fast E30s are running rates in the 450#-600# range front and rear. Ed York ran 450 or 475 on all 4 corners and was a consistent winner at Summit Point and holds the Nelson Ledges track record in his E30 that he ran a couple of years ago. I spoke with guy who owns that E30 now, and he runs it the same way.

[CrunchyFrog]

As these last two posts point out, spring rate is very track dependant.

Personally I sway to softer set ups when I can.