2.9l M50 SCed E30 build....

[turboeta]

Hey whats going on guys, figured I would post about my upcoming E30 build..

Anyhow, here is my list so far..

M50 block w/ s50 crank and cams
Dinan Powerdyne supercharger w/8psi pulley <-- Not my first choice, but it was cheap
28lb injectors
Ported stock manifolds for now, no cats
Sachs HD clutch and PP
Still haven't decided on tuning, thinking MS..but will probably just go with some dinan or NickG software

Thats my list for now, with everything else associated with a M50 swap.


Pics when I get my motor :)

[PiercedE30]

You may want to also throw a set of pistons in there aswell.
With my 2.9, using OEM parts (s50 crank, M52 rods, M50TU pistons) my piston crowns were 0.031" above the deck of the block. I had to use a 0.120" MLS head gasket to drop my compression ratio down to 11.7:1.
High compression + boost = BOOM!!!

[Ray Smoodiver]

You may want to also throw a set of pistons in there aswell.
With my 2.9, using OEM parts (s50 crank, M52 rods, M50TU pistons) my piston crowns were 0.031" above the deck of the block. I had to use a 0.120" MLS head gasket to drop my compression ratio down to 11.7:1.
High compression + boost = BOOM!!!

Not really, high compression + boost = not so shit off boost. Most boosted motors these days run "relatively" high compression ratios.

I would have no problem boosting a 11.5 or 12:1 motor as long as the tuning was spot on, there was definitely some knock sensing going on and maybe water injection.

[BrandC]

High compression + boost = BOOM!!!

An auto teacher of mine recently told me about a guy who has consistently proved this wrong. The point this "tuner" was trying to make is that engine management is super important for any application.

He took a B18C on stock compression (relatively high from factory) and boosted it with 28psi, just with a composite multi-layer headgasket and ARP head bolts. He dynoed it 200 times with an aftermarket ECU/stand-alone, not one hiccup from the motor. He then dynoed it with the stock engine management and KABOOM.

Lesson: It's not compression and boost that kills the engine, it's cheapasses who do. GO MEGASQUIRT.

[mops]

dont confuse static compression with dynamic compression. with wilder camp you drop dynamic compression and that allows you to get away with boost... but turbo on a wild cam engine it's whole another story...

[Ray Smoodiver]

dont confuse static compression with dynamic compression. with wilder camp you drop dynamic compression and that allows you to get away with boost... but turbo on a wild cam engine it's whole another story...

Typically, turbo cams are longer duration with less rise, no?

[PiercedE30]

Alright, alright, alright.
Key here is: TUNING and ENGINE MANAGEMENT.

[Farbin Kaiber]

Typically, turbo cams are longer duration with less rise, no?

yep, longer durration to let the turbo blow thru the exhaust valve to empty the combustion chamber of burnt gasses, let the turbo clear the chamber, in essence anyway.

[dark89e30]

Turbo cams usually have more lift and longer exhaust duration but have less overlap to prevent the turbo from blowing a/f mix through the chamber. The lack of overlap is to keep your boost up and to keep your turbo from working too hard. And there is a reason that Porsches Turbo cars run no more than 9.0:1(997). You can get more power out of lower compression and higher boost. Plus its alot safer.