M30 swap

[Jean]

B35 stuff fits, not much needed in terms of modifications. Tight, but fits.

[sacse30]

I was advised that for clearance purposes, it's better to use the b35 exhaust manifold and downpipes. That's what I bought and will be installing in the next couple of weeks.

[Jean]

No. Ecu will mount in the stock location, but only using 2 out of 4 bolts, with the harness plug facing the firewall.

[CorvallisBMW]

I think so

[LowR3V'in]

Do you need to run the ecu in the engine bay with the b35 harness?

[Jean]

So I have a wire harness from an 87 325i convertible and one from a 88 e32 automatic which came with the engine. Which one would be easiest to fit? I'm leaning towards the 325i harness.

The e32/e34 obviously fits the engine better and looks cleaner than the e30 harness, if it's from a pre 91 car it will have a round 20pin c101 as well so no splicing needed. But you can use either one :)

[CorvallisBMW]

Thanks Darin how's the car running? My battery is the trunk so I will probably will have some issues there but should be workable.

Car's running great, I haven't gotten to work on it much this summer since I've been traveling for work a lot. It's getting new suspension (again) when I get back next weekend, I'm still not happy with how it handles.

The battery being in the trunk shouldn't be an issue, just keep the factory battery wire exactly where it is.

[1987E30project]

wire harness

Definitely use the e30 harness. You'll need to lengthen your TPS wire, but other than that it should be a straight plug-and-play operation.

Thanks Darin how's the car running? My battery is the trunk so I will probably will have some issues there but should be workable.

[CorvallisBMW]

Definitely use the e30 harness. You'll need to lengthen your TPS wire, but other than that it should be a straight plug-and-play operation.

[1987E30project]

Two harnesses which one to use

So I have a wire harness from an 87 325i convertible and one from a 88 e32 automatic which came with the engine. Which one would be easiest to fit? I'm leaning towards the 325i harness.

[1987E30project]

bump. im actually looking to do my exhaust as well, but i will use e34 downpipes and graft it to the i exhaust.

and bump for good info.

That is what I'm doing. But the downpipes are from an e32. I'll be posting more pictures soon.

[bataangpinoy]

bump. im actually looking to do my exhaust as well, but i will use e34 downpipes and graft it to the i exhaust.

and bump for good info.

[1987E30project]

Cutting the M30 downpipes

So I took off the insulation of the downpipes and then cut them a little long. Its going to take several cuts I think to get them to fit the 325i exhaust but I will be screwed if I leave them too short.


The horror, the horror



For now I will be using the 325i exhaust but somewhere down the road I would like a nicely done system.

[wildstoats]

interesting.
My oilpan is about 1/8th of an inch from the steering rack and the e32
downpipes were still way too short.

They would go right into the firewall. :(
Can you take some pictures?

Sure thing. Next time I get the front end up in the air I will snap a few. The only contact point I have is a tiny bit on my control arm lollipop. Nothing I'm terribly concerned about though. My exhaust definitely falls into the category of "quick and dirty" haha.

[e30m3s54turbo]

I like what you doing to your e30.