E36 KW V3 on E85 Z4M

[Mangozac]

I've been considering some coilovers for a while and have come across a used set of E36 KW V3 for a good price. My understanding is that the rears are identical and fronts are almost identical other than the strut length being slightly longer on the E36.

Given that I don't intend to slam the car on its guts (legal requirement is at least 100mm ground clearance but I doubt I would go that low), can anybody comment on the suitability of the E36 coilovers on my E85 Z4M?

Thanks!

 

[BTZ461]

The valving on the E36 kit would be quite different I would image, are the rear numbers the same for the E36 as the Z4M?

Edit: Just checked, the part numbers are quite different. Do you at your risk own risk.

 

[GuidoK]

They are completely different.
The e36 v3 systems are on the front linear (like for the z4m clubsports are) and on the z4m v3 they are progressive.
Also the rear spring is very much different.

It doesn't mean they won't fit but balance would be very different. Different doesn't mean bad. Linear springs have considerable advantages on track.
Also for the e36 I see that there are currently 3 v3 systems, one for the e36 m3 and 2 for the non m. (and this is for the 2nd gen e36, there are of course 2 gens e36)
Not really clear what the differences are.

It could be that they're internally all the same, just as it is between z4 and z4m V3 struts, and on the z4, the V3 dampers and Clubsport dampers are also the same. The fronts are of course a different mounting between z4 and z4m, but valving is the same. They just correct the different weight and springs (V3, clubsport) by giving different basic default dampening setting for the different cars&systems.
With KW, a different number on a shock doesn't mean that its physically a different shock. It can also mean that it came from a different set.

But how the e36 fits in all of this I dont know. What strikes me as different is that V3 sets for the e36 are a lot cheaper (all 3 designs are the same price and cheaper), and the z4 sets are considerably more expensive (z4m the most expensive). The difference between an e36 v3 set and a z4m v3 set is 600 euro in the KW webshop.

If I would estimate is that the front springs on the e36 V3 sets are suitable for the z4m. They are of the same stiffness as the z4m clubsport kit, only the pretension spring is a little bit stiffer on the e36 kit.
But the rear springs are a different shape, and have different spring perch sizes, so there might be a chance that the rear springs wont fit.
E36 rear axle and suspension arms are different from the e46/e85.
Rear shock differences between e36 and e46/e85: I really dont know what to expect.

 

[Mangozac]

Thanks guys, you've made some very good points about the valving on the two applications. It seems there would be a few too many unknowns further than simply fitment to make it worth the risk.

But how the e36 fits in all of this I dont know. What strikes me as different is that V3 sets for the e36 are a lot cheaper (all 3 designs are the same price and cheaper), and the z4 sets are considerably more expensive (z4m the most expensive). The difference between an e36 v3 set and a z4m v3 set is 600 euro in the KW webshop.

That may be because they have to customise the height of the front shock solely for the Z4M application?

 

[GuidoK]

That may be because they have to customise the height of the front shock solely for the Z4M application?

I really don't know. The springs that they use are of equal lenght.
Could be that the z4m has a different lenght shock body than the e36. But piston length is I think the same, as the spring lenght is the same.
I don't own either of the cars so I can't compare it. But strut lenght is probably more of a risk than valving. Valving is 2 way adjustable (thats the slow valving), and I think that the speed valves are shimmed relatively the same and is more of an importance in little bumps/comfort, and less on roadholding around corners.

If its's a really cheap set it might be worth the risk and sell it on if it doesn't fit properly.
That would shine a lot of light on this matter. Now its mostly guessing.
No one takes the step of actually fit&try
I say go for it, but it's not my money and time put into it

But be prepared to at least buy a different set of rear springs. That stuff is also expensive at KW I suspect.
And as those are progressive springs its difficult to match them up to cheaper springs from other tuningmanufacturers.

I also don't know why they made the V3 set for the z4m progressive in the front where all other V3 sets, for e36, e46 and normal z4 are linear sets, just like the z4m clubsport set is linear.
Linear sets are less comfortable as little bumps are compliant wiht the same spring tension as bigger bumps, but the way the car dives in corners is so much more predictable imho. From a performance pov a linear spring setup is a gain imho.

Maybe linear in the rear even better too. I always thought that the rear axle is the weak spot on the e85 chassis. Especially stock its like a dog dragging his bottom over the grass, and stiffening rear springs, arb and bushings made it more solid, but when and when not it breaks out/sets a step to the side is still fairly unpredictable. The front suspension/trackarm setup is way more predictable.

 

[Mangozac]

If its's a really cheap set it might be worth the risk and sell it on if it doesn't fit properly.
That would shine a lot of light on this matter. Now its mostly guessing.
No one takes the step of actually fit&try
I say go for it, but it's not my money and time put into it

I know what you mean but unfortunately they're not cheap enough for the risk, especially given they've come off a track car and would probably want to be rebuilt too :?