M42 turbo dyno results

[e30pq]

That's a bummer. Is it a gearbox / diff failure? I'm only saying that because the noise was consistent while you were rolling in neutral.

It was a transmission failure. We put that trans in a couple months ago to test it (it was a spare). The first time we tested it we were having some miss-shift issues so we were planning on pulling it out in favor of the good trans we had in there previously. We didn't get a chance to make that change before this last test.

Rob pulled the bad trans out of the car last night. We plan on taking it apart just to see how bad it looks in there.

We we got back to trailer after that session the only gear I had was 4th. Everything else including reverse was gone.

[e30pq]

Coming from an American V8 background with big displacement/big power (a Nova in the high 9's) seeing this makes me all sorts of giddy! I have to say I'm really excited to see big power coming out of small packages these days. Thanks for sharing!

Thanks for the kind words.

Did you notice the 2 E46 M3's that tried to follow me after I got around those Mustangs?

The M42 tends to be overlooked in favor of S14's or S or M50/52's. The S14 is a great engine but it's very expensive to build.

We noticed a Euro S50 for sale on Bimmerforums. It was built and it was making 333hp on the dyno before it was pulled for sale. They were asking $10.5k.

We could build an M42 turbo and sell it for that price. We could probably ship it with an E30 wrapped around it.

[e30guydownunder]

It was a transmission failure. We put that trans in a couple months ago to test it (it was a spare). The first time we tested it we were having some miss-shift issues so we were planning on pulling it out in favor of the good trans we had in there previously. We didn't get a chance to make that change before this last test.

Rob pulled the bad trans out of the car last night. We plan on taking it apart just to see how bad it looks in there.

We we got back to trailer after that session the only gear I had was 4th. Everything else including reverse was gone.

It was the G240? And I think you were in second gear? They have a habit of falling apart even behind an S50 in a swapped E30. I picked up a G260 pretty cheap so going to run with that (also given me room for the 240mm clutch).

[e30pq]

It was the G240? And I think you were in second gear? They have a habit of falling apart even behind an S50 in a swapped E30. I picked up a G260 pretty cheap so going to run with that (also given me room for the 240mm clutch).

Yes it was a G240. It blew up in 3rd gear but 2nd gear was difficult to get on downshifts.

[gearheadE30]

On an interesting note, the transmission that I blew a gear in also killed third, and 2 of the 3 transmissions I've had now had the difficult downshift to second.

[rob_e30]

I dropped another spare in today and took it for a test drive... grinds on 2nd gear downshift (at least when cold). I think we're going to open up at least 3 of the 4 we have here to see if we can build one more solid tranny.

[Supadave]

Why don't you throw a zf behind it?

[e30pq]

We have considered it be we really want to stay with a G240. A couple of reasons why we don't go ZF:

1) If we go with a ZF we need to invest in another built diff with a ratio that works with the ZF. We already have a 3.65 LSD that is built up which works for either a G240 or G260. That amounts to another $1k plus for a new diff.

2) ZF is stronger but they still break. ZF's are more expensive used vs. used G240.

They also say the ZF weighs more than a G240.

[Supadave]

Ya the 240 is one of lightest trans out there.

[rob_e30]

We did a time study on the swap last weekend and confirmed that we can jack the car up, swap transmissions, and have it back on the ground and driving in between 2 and 2.5 hours. We can shorten that some if we don't have to swap the guibo and shift linkage. If we rework the exhaust we could likely shorten that time up some more.

Rob.

[Supadave]

Wow, that's pretty fast

[Supadave]

Are doing any thing to make the the trans stronger this time?