how much power from 2.9 stroker?

[backtrail69]

You've been driving 2002s too much...those are slow, thats why it feels fast. :P Get in my over 250 whp (don't have a real number yet) turbo m20, you will feel what a m20 feels like when it isn't breathing through a straw...

[winstontj]

Funny thing is I have no idea what is in this motor. I haven't even pulled the valve cover and before I started digging around here & e30tech I would have sworn up and down that it was a stock displacement motor because that's what the PO said.

Also I'm sure that I'm probably only getting ~150 to the wheels right now because the car runs like SH*T. I need to do a bunch of work on it. I'd love to just buy a bunch of parts (like vacuum hoses, spark plug arrangements, etc.) and pay for a dyno session and someone who knows how to tune these things to teach me what's up.

I also have stock exhaust (header but with stock cat & exhaust) so that's probably holding back more that the motor could put out. Even more funny is I only use the car to go to whole foods once a week and on weekends... other than that it just sits.

~200 at the wheels (NA) must be effing fast though. Even with my lowly 178rwhp the torque is awesome. I'm trying to get the documents scanned and put up so I can post torque numbers too. I think I'll just look for a dyno and get another tuning session so I'm not running around saying something without PROOF!

[StereoInstaller1]

Should I be happy with my 178rwhp then?

Another way to build a really torque-y stroker is to start with an M30 block... Just kidding, man.

178 is a hell of a nice number from a mild stroker, even though yours sounds more than "mild".

Several others have made the observation that BMW never really raced the M20, but ran the shit out of the M30 (S38,S88, etc) and the M10 (S14) blocks and learned a bunch with the M50 series.

I do wish I had your motor though.

Luke

[SA E30]

I dont think I would build a stroker with a longer stroke than 84mm... just not sure how well it will rev...

but then I also wasn't sure that my 84mm stroke would rev that well, and it does... so maybe 86mm throw wont be that bad :)

[winstontj]

it was 192whp

178 isnt that far off from that. How can I tell what (if anything) has beem done to the car? I have to adjust the valves soon so there is a start but what about bottom end?

Will I be able to tell the crank differences any other way? If I had to guess I would have said it was stock but if you guys say that 192 - 210 takes work then it makes me wonder.

I have very little records and hve no idea who the PO was

[Sean]

Chris...I hear ya.

I've been enjoying mine...but when I do another one, and someday, I will (I'll turbo this one someday) - I'm going to do pretty much Metric Mechanic's biggest stroker - but of course, source out the parts myself. :D

Strokers are fun, but they are not powerhouses...frankly, the M20 is a great motor, but it won't be breaking any power records staying NA. Just fact of life.

Still a fun motor though! GOD I LOVE TORQUE! :D

[nando]

you must mean 86mm bore/84mm stroke?

I don't know how much power it would make, but it would have a ton of torque. it's probably a better idea to tune the M20 for a wide torque band than trying to go after peak HP #s. if I did it again, I would go with the 84mm crank instead of the 81..

[Addissimo]

it was 192whp

word.

~220bhp.

too bad he burned oil.

[digger]

The highest I have seen is Jordan's old 2.8 stroker at like 210ish RWHP. He had extensive head work and high compression.

it was 192whp

[winstontj]

Should I be happy with my 178rwhp then? The dyno sheet is about 4 years old and with the way the motor is running I'm debating paying for a dyno session to get it back to that state (after I do a comp & leakdown test).

For all I know it could be a stroker.... Haven't even pulled the valve cover yet. If I had a stock exhaust (which I do I think) and stock motor could it be possible to get to that 178rwhp number on a bav auto chip, MAF conversion, uprated injectors & other little bits or would it take more like headwork, cam & exhaust?


Thanks for the reply.

[backtrail69]

The highest I have seen is Jordan's old 2.8 stroker at like 210ish RWHP. He had extensive head work and high compression.

[winstontj]

Just wondering. I have not done a compression or leakdown test on my motor but it came with a dyno sheet stating 178rwhp. Wondering what the 2.9L stroker motors put out with ~10:1cr pistons & moderate cam.

Do they achieve 250 at the wheels?