best course

Post Tue Jan 07, 2014 8:18 pm

in the process of stripping out from the rear of the gear box back of my drive train on my 1990 m20b25 auto cabby 127000 miles on the clock. ive owned it over 7 years and done the beam bush's in the past and the cam belt. the idea is to re fresh everything underneath front to back bu8t also want to fit a manual box. here in lies my dilemma. with fitting the manual box and removing the engine to do so do i go for a m50/52 conversion cause its out anyway or stick with the original. not afraid of a bit of graft. i work on my brothers 1983 mk1 golf gti and my old mans 1987 320 more door as well as his 1954 all steel ford pop running a 4.6 rover block.

Post Tue Jan 07, 2014 9:16 pm

Converting to manual is a walk in the park, as you're just bolting on parts that were meant to go together in the first place. But when it comes to going M5x, you're looking at custom exhaust manifolds alongside the sourcing of specific non-BMW parts. The M5x swap is well documented and there's plenty of help out there for you, but it will cost you plenty in either time or money, or both, whereas the auto/manual swap can be done in a weekend for relative pennies.

The wiki has plenty of info on both topics to help you out.

Post Tue Jan 07, 2014 9:32 pm

got all the wiki pages saved that i need. was just thinking if the block is out would it be worthwhile.

Post Tue Jan 07, 2014 9:48 pm

I wouldn't want to dissuade you since I don't have an M50 engine myself, but a) you've already got a 2.5 lump so going to an M50 engine won't really be a massive power boost, just a more refined drive, which may not justify the expense of the conversion and b) you've got a cabby, which is the bodyshell least prepared to deal with increased power due to its weight and overall floppiness.

If you were going from a 1.6 Touring I'd heavily stress you do the engine swap, but as it stands, I don't really think it's worth doing to your current car.

Post Wed Jan 08, 2014 2:44 pm

the bodyshell thing was mentioned. its not so much disuading me, i was more so throwing it out there seems as i would have the engine out anyway with a gear box swap. i like the auto but after all this time it doesnt feel like either the box or maybe the diff isnt locking up so will do the gear box and diff as well as the whole underside of the car. i'll never get rid of it so may as well spend a few quid on her.

Post Wed Jan 08, 2014 4:10 pm

I guess it also depends how long you can live with it off the road, and if you have the space to do it? I'm 25% of the way through my M52 conversion (old M10 engine out and M52 about to go in), but the E30 is not my daily driver but my 3rd car, I have a double garage where it can sit in pieces, and it's gonna be a nice power hike from the M10 engine.

Good luck if you do decide to go for it.

Post Wed Jan 08, 2014 7:24 pm

currently driving round in my brothers mk1 golf gti. my bm is in his double garagein pieces but still has the engine and gearbox in place. the bm is my daily with a commute from cov to solihull and back min 5 days a week. the golf is knowhere near as refined as my bm and i want it back asap.