Suspension forensics

viphoto

viphoto

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Ok guys I need your collective knowledge to figure this out. Trying to figure out if my car has tuned springs or maybe just cut stock ones?.... Also will new bilstiens help cure excessive body roll?
Details :
1970 2800 cs
16 inch wheels 205 / 55 tires
26 mm front bar 22.55mm rear bar
KYB shocks

So I am trying to figure out if they also did the springs, which I would assume they would have done when they did the bars. Comparing my car to DeQuincey's suspension measurements in his post (see below) it seems like it did get some springs (but I did see a paint stripe on one which leads me to believe they may be cut original BMW ...Carl said they are no paint stripes on his...not sure about other kits). The car corners great but the body roll seems pretty substantial. Planning on installing new bilstiens but wondering if a set La Jolla springs would be worth the investment. I have to disclose I do have a warped sense of what is acceptable body roll after driving my 308 GTB recently...(apples to oranges I know and a decade newer car) but the coupe is such a joy to drive and would be more so with out the excessive body roll.

I saw DeQuincey's post http://www.e9coupe.com/forum/thread...all-and-not-so-small-bits-around.14519/page-5
It's post #86
I did the same measurements and came pretty close to his numbers for the "After" version which leads me to believe that the car was lowered....
My Measurements
Center of wheel to bottom lip of fender F 13 5/8ths" R 14 1/8th"
Top of tire to bottom lip of fender F 1" R 1 1/4th "

Any input from those of you that have been down this road is appreciated.
CS susp.jpg
 
Shocks aren't going to help with your perceived excess body roll. If your springs are cut, they will be stiffer than stock. A readily available aftermarket front swaybar with a 28.5 mm diameter would be about 45% stiffer than your 26 mm piece.
 
Cut springs will have fewer coils than stock. The performance aftermarket springs I've seen have always had the same number. I don't know the number of stock coils offhand... usually 5.5 or 6.5 turns for the front I think.
 
Layne said:
Cut springs will have fewer coils than stock. The performance aftermarket springs I've seen have always had the same number. I don't know the number of stock coils offhand... usually 5.5 or 6.5 turns for the front I think.
Click to expand...
Doing my best Homer Simpson.... Doh! Thanks Layne, that's a great idea. I will count them and go from there. Anybody out there with a stock set of springs off the car that can c0unt the coils?
Cheers
 
Ok, I'm going to need Chris or Steve to tell me which rear springs are for the 71 2800 and the 74 3.0 CS but I rarely throw anything out (because I no longer pay attention to my wife). But here is a picture with measurement of the front off the 71 2800 CS.

I can only make a suggestion regarding body roll in that you need to determine if it's coming from the rear, front or both. I have rear toe/camber adjusters and the excessive toe in on the left wheel caused a very unsettling rear dip in corners, Drew and SF Don were both instrumental in pointing out the possible issues and Ray at Munichauto in Austin put it on his :) NEW:) alignment machine and set it up correctly, the difference was immediately noticeable and at that point I put the IE heavy rear sway bar on to match the front. I am also running 225/45/16 all around and the ride is stiff but comfortable- especially on the highway. With the rear sway bar installed I can now "slide" the rear end around corners, which may not be the fastest way to get from point A to point B, but I can feel the sidewall flex before they break lose and I'm very comfortable with that. I am also using CN springs and Bilsteins, new perches and all new bushings, also poly bushings on the sway bar links. IE makes some rear sub-frame bushings that will also eliminate flex substantially from what I understand. I have them on My 320IS and I love the feel.
stock springs.jpg
 
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