Impact of OBD2 US Exhaust on Power Output

[nick325xit 5spd]

Has anyone seen what he actual effect of running the OBD2 manifolds and midpipe on the S50B32 are? Are we talking about a mild power loss of a few hp, or does it plug the motor up horribly?

[kovrol]

why are you want to mount those up on an S50B32??? I think it can dramaticaly decreese the whole powerband, cause the M52 manifold has different input holes then the euro engine output holes (oval vs circle).
Mounting up the euro manifold onto the M52 is a different way cause the euro manifold has larger input holes and the overall space for the exhaust gas is nearly the same...i have a shematic drawings from this, I can load up within 7-8hours when I get home and you will see what I'm talking about.

[nick325xit 5spd]

why are you want to mount those up on an S50B32??? I think it can dramaticaly decreese the whole powerband, cause the M52 manifold has different input holes then the euro engine output holes (oval vs circle).
Mounting up the euro manifold onto the M52 is a different way cause the euro manifold has larger input holes and the overall space for the exhaust gas is nearly the same...i have a shematic drawings from this, I can load up within 7-8hours when I get home and you will see what I'm talking about.

I'm curious is why. I know that the dimensions on the OBD2 manifolds are different, and I have the correct headers as well. I'm largely curious here, although the reality is that using the euro headers will require cutting them up a bit, which I don't exactly love.

[MauiM3Mania]

Have you tried this combination yet?

[nick325xit 5spd]

Nah. I just pulled the motor out of the M3 today. I'll be pulling the S50US out of the "330" tomorrow and shoving the engine in then. I'm currently debating between porting out the eBay header set that I have (and have fixed the massive flange leak in) and just fixing the damned euro set. The much greater than expected pain in the ass factor of putting the OBDII manifolds into an E30 ruled that out. They don't solve any of the issues that I had hoped they would.

[nick325xit 5spd]

Ended up porting out my old set of ebay headers from the S50US. It'll be interesting to see how it dynos. I just got it running last night, but have a bit more work to do before it's drivable.

[MauiM3Mania]

Into which car are these headers/engine going?

[nick325xit 5spd]

Into which car are these headers/engine going?

An E30. Hence the reluctance to do the butchering required to make the stock euro headers fit properly. (And it's a lot of butchering if you aren't willing to run eyeball arms.)