m30 swap questions

[cheapshot]

I have a couple of questions as I am preparing to do an m30 swap. I have been weighing my options between doing a super eta, m50, or m30 swap and think I have settled on the m30. However, I am still open to suggestions on which route to go. I have an 86 325e and have sorted out the suspension and am ready to move on to making more power. The reason for settling on the m30 above the others is the ability to make more power, tons of torque, and cheap purchase price. I have located a 735i motor, harness, and dme for cheap with good miles but it has an auto trans. Will my m20 trans work with the m30? Also, with my car being an eta, pre 86 build date, what issues might I expect to run into with wiring the car? I see that with some harnesses all that it is needed is to lengthen a few wires, is this possible with the eta or should I splice in the harness from the donor? Sorry for the seemingly simple questions. I have read and researched quite a bit over the past week and would like to address these two things before making the purchase. Thanks!

[Jean]

No, your m20 tranny won't work with M30. You didn't read any of the long threads on this swap did you? This is one of the MAIN/BASIC components of the swap you shouldn't even be asking about if you are about to do the swap imho....

Here you go - http://www.r3vlimited.com/board/showthread.php?t=163724

[cheapshot]

Yes, I did. I did not say that I was about to do the swap, I said I was preparing. I thought, from my research, that it would not work but while talking with an older BMW guy this morning he said he thought it should. It does however look like a m10 tranny will work? The reason I am asking this specific question is I have not been able to locate a m30 manual trans locally. I just wanted to clarify. Also, can you address my question on the harness issue? I have done 4 different swaps over the years but never in a BMW. This is definitely something I can tackle, just want to make sure I have my ducks in a row before begining. Thanks in advance for your help.

[Jean]

You can make the m20 harness work, you can also make an auto m30 tranny work. But the 'ideal' harness would be one from the manual m30 car.... in terms of "fitment on the engine" (not requiring extending anything) and not having to remove or clean up automatic tranny wires.

You can go either way for wiring.

Yes, some have used m10 tranny, as it's bellhousing matches the m10/m30 vs the m20.

[Good & Tight]

You will also need engine mounts fabricated to bolt in the engine.

[cheapshot]

I just saw in your sig that you make the mounts? Can you tell me how much they are and lead time? Also, if I use the m10 tranny should I also get the driveshaft out of the same car? I was able to source one today, just have to go and pick it up. Is the m10 tranny strong enough to handle the power of the m30? The reason I ask this is that I know a lot of m10 guys switch to the m30 trans when they are making serious power. I am planning on doing a fairly mild NA motor, 225-240 hp at the crank.

[Good & Tight]

I just saw in your sig that you make the mounts? Can you tell me how much they are and lead time? Also, if I use the m10 tranny should I also get the driveshaft out of the same car? I was able to source one today, just have to go and pick it up. Is the m10 tranny strong enough to handle the power of the m30? The reason I ask this is that I know a lot of m10 guys switch to the m30 trans when they are making serious power. I am planning on doing a fairly mild NA motor, 225-240 hp at the crank.

M30 B35 mounts are $270 shipped. They have two mounting positions which the farthest set back position will allow the a/c compressor to clear the radiator. Lead time is within two weeks delivered to your door.

IMO your better off getting a M30 trans. Yes the M10 will last for a bit but getting a clutch to handle the power offsets the initial costs if you go with the M30 trans from the start.

[stinkydriverx]

get good and tights mounts. I have them, they work. They are priced great. You have no excuse.
Go to junkyard and source a trans out of an early m30 powered manual e28. everyone can correct me if they feel like im wrong. But the g260/6 trans is the one I chose to go with, due to many people on this forum.

[Jean]

E34 535i is the tranny to get, late model g260/6 with the horizontal fins. But the e28 535i will work as well!

[LowR3V'in]

e28s have the 260/6 too.

[Jean]

e28s have the 260/6 too.

Yes, thats why I mentioned E34 535i as well.... :) IIRC e28 535i had an early and late g260 vs e34 only obviously having a late one.