M-Coupe suspension onto E36 M3?

[rader]

So eventually I want to get a coilover kit for my '01 M-Coupe. Being that I am a total cheapskate and the M-Coupe dampers have only 25k miles on them and shocks on my E36 M3 Sedan are very tired with 100k miles I am thinking about swaping the M-Coupe shocks over to the M3. From what I have read the front suspension on the E36/8 is grafted from the E36. Of course on the rear the Coupe has rear-trailing arm suspension, but the shocks on both cars mount on-axis with the wheel hub so I assume the damping rates are similar. The mounting locataions and mounting hardware look identical. I have not yet measured the length of the shock to see if they have the same operating range but I would assume so. Different part numbers in ETK for the dampers, but then again the s52 and s54 M-Coupes have different part numbers and we know those are interchangable.
Also in some recent posts I read that the aluminum Z4 front control arms are interchangeable with E36, E36/8. How about swapping Z4 control arms onto my M-Coupe, and then replacing the M3 control arms with the less tired ones from the Coupe?
Any reasons not to try the above? If not I may just get both cars up on jackstands and try it out.

[Johann]

M Coupe rear suspension is not at all like the rear suspension of the M3. The M Coupe uses a trailing arm rear suspension, carried over from the E30 and E36 318ti. The M3 uses a multilink rear suspension.

If the shocks fit, its likely they won't be the correct damping rates, due to the differences in suspensions, spring rates, and weights between the M3 and M Coupe. Besides, OEM shocks are a cost-driven item... at 25,000 miles, the M Coupe shocks likely don't have the same damping characteristics as new.

I would imagine companies like BMW do some frequency analysis to determine shock damping rates, then companies like Sachs/Boge build them to those specs.

Sell them for whatever you can get, and buy yourself a set of nice Bilstien Sports or Koni Yellows for your M3. You'll thank yourself.

Jonathan

[rader]

The main reason I am trying to cheap out on the M3 is because the car is for sale. If I was keeping it I would go for Biltein's no question, but if the car sells soon there is no way I would ever recoupe the cost of the shocks either in resale or from my own use. I am not seeing to much action on the car right now and I honestly don't expect to sell it until spring/summer so I would like to drive it in the meantime.
What I want to acheive is an improvement in ride for the M3 over the 100k shocks on there now. I know the rear suspension is totally different on both cars, but the shock attaches directly to the wheel hub which implies a 1:1 wheel rate for damping. Both cars are 50/50 and within about 10% in weight and about the same stiffness on suspension with the edge going to the Coupe. I understand also that the damping factor will change as the shock compresses and the M3/M-Coupe are probably different in this respect. With my experience with adjustable Koni's I've found that it isn't really important to have the damping factor perfect especially for street driving. You just need to get it in the range where you don't get oscillations from underdamping or wheel hop from overdamping. The only way I am going to find that out is by actaully swapping them over and driving. The reason I asked this on the board is to find out if there is some fatal mistake I am overlooking. Like if I swap the shocks over will the subframe on the M3 self destruct as soon as I lower the car off the jackstands?