E36 M3 Throttles

[s13b]

Basically I have a set of the above mentioned throttles that I was going to use as part of an M50 turbo conversion sitting in my lock up...

Do these fit or is it worth trying to fit these to the M20?

Adapter plates and ECU mapping is no problem, just wondered if there is any value in doing this? I am planning on either 2.8 m52 stroker for the M20, or just the m50 turbo swap...

BTW I actually like the m20 engine and would probably prefer this option in the long term if decent power and torque gains can be made.

Thanks

[basketweave]

I don't think it is worth doing, IMO the throttles are too big for the 2V M20. If you ran the throttles far enough away from the head you could taper down nicely to match the intake port, but you are limited with room to do this.

40mm throttle butterflies are ideal.

Who has done a bike carb setup?

[HairyScreech]

Forget bike carbs, it will be a loss of response and economy for a small top end gain.
Might be worth it if the runners are done to correct lengths and diameters and the car is intended for quite a narrow operating range but very fairly is this the case.

The e36 m3 throttles have been documented on here many times, the results are mixed to poor due to the size of the throttles, i think i worked out elsewhere that a 2.8 would be best off with around a 38mm throttle per cylinder, which is rare to find.
Certainly few off the shelf kits have correct throttle size (all 40-45mm+ ) as they all use standard webcon/jenvey etc style throttles.

Our 2.5 and 2.8 cylinders are only similar in capacity to a 1.6-1.8 4 cylinder so throttles need to be sized with the capacity per cylinder in mind.

Obviously highly tuned m20s will differ from these points but they are few and far between.


What do you consider decent power and torque gains?