m30 or m50

[DanThe]

the only readily available gearbox is the E30 318i M40 box

That's for the M50? Just out of interest, what flywheel and clutch combo is that using?
I read on here somewhere that the M50 clutch and flywheel can be used with the M40 box, but wasnt sure if that's right or if you get the same problem of the gearbox rotating like with the M20 box.

It may all fit together but like anything else its only an idea until someone has actually done the conversion and run it IMO.
Personally I wouldnt use a 318 box on the back of a 200hp engine

[jmc330i]

the only readily available gearbox is the E30 318i M40 box

That's for the M50? Just out of interest, what flywheel and clutch combo is that using?
I read on here somewhere that the M50 clutch and flywheel can be used with the M40 box, but wasnt sure if that's right or if you get the same problem of the gearbox rotating like with the M20 box.

It may all fit together but like anything else its only an idea until someone has actually done the conversion and run it IMO.
Personally I wouldnt use a 318 box on the back of a 200hp engine

m-dtech on here has used the 318iS box on an M50 conversion, not sure if its running though.

[Jhonno]

iirc some people have run some big power through M40 boxes... Plus its not power that kills boxes its torque and think of Malcoms turbo's cab and Chris'.. Prob running more torque than an M50/52

[clubfx2]

What other boxes can be used?

[reggid]

M30 is the one to go for 215ish bhp 220ish ft/lbs - cheap as chips to buy a new engine as well - can be tuned to give 230+ bhp without too much £Â£

The M50 produces less torque at 4000rpm than an m20! By contrast, I had my 335 dyno'd the other day and it was producing 165ft/lbs at 1500rpm!!!

The M50 makes more torque than the M20 at any engine speed becasue of vanos. The M20 has no torque and is not a torquey engine.

I am not a fan of the M50 swap becasue the engines are 12-15years old now plus the advanatge over a m20 is about 10-15% across the board and thats if the engine is in good nick, so a good 2.7 is faster and better IMO. The M52 is a better allround engine though and much torquier and potentially powerful with an M50 manifold swap and bolt ons so its the one i'd be going for even if its more troublesome than the m50. A built M30 has huge potential but the M52 would be my pick if a swap was mandatory.