M5 engine swap... questions

[myred318i]

Help me out here... My friend has an '87 535 (e28), he's interested in buying a rebuilt M5 motor to swap into it.

Has anyone done this before? Do you know if it's a straightforward swap, or are there other changes necessary that would make the project more of a PITA than it's worth.

Thanks for any input you can give! :

[Kos-motate139]

I doubt it would be that hard to slap an S38 in there...just that those engines are kinda expensive to get parts for.

[JamesM3M5]

He will need an M5 computer, wiring harness, and the whole engine from air filter box to exhaust manifolds. He would also need to relocate the battery, because the M5 airbox lives where his battery is. There are other a few other little changes, like wiring and miscellaneous bracketry, that will drive you crazy if you're not expecting them.

He will also need a Getrag 265 or 280 to bolt up to it. The 1986+ Getrag 260 may not handle the power and torque of the M5 engine for long. The M5 came with a bigger diff (same as the later V8 and V12), the massive Getrag 280, and a free-flowing, quiet, but heavy exhaust.

If he wants better power and performance, get a Jim C chip, LW flywheel from Metric Mechanic, and a 3.73 differential. Screw the M5 engine swap. It will cost more than the car is worth!! If you want a lot more power, you can always find an E34 535i engine with 208HP Stock easily chipped to 230+. They are a direct bolt-in to any E28 with manual transmission. You will need to fabricate the passenger side engine mount, from what I hear. Total cost for that conversion is well under $2k.

JamesM

[myred318i]

Thanks, James... that's exactly what I'm looking for... some honest opinion about what could, should , or would he do to get the desired effects (increased power)

Thanks!!!