how much power from 2.9 stroker?

[winstontj]

If new stock = 152whp then I would say it's 100% possible to get up to 178whp (my car) on just a few upgrades.

Retail (flyhweel) published numbers:
Chip = 15hp
Split Second Intake & management system = 15hp
Adj. FPR, uprated injectors = 5hp
Exhaust = 5hp (have header & stock so maybe this does not count)

Total = ~40hp (flywheel)

Divide that number in half and you get ~20hp increase which would be reasonable to bring the car up to ~172whp. Factor in variables, running AVGAS for dyno session, car in perfect tune, etc. and I believe that it's possible to get up to 178whp from a fresh stock motor with only bolt on upgrades.

Can anyone toss this argument out the window? I'm going to pull the valve cover this weekend as well as pull the plugs and take a peek at the pistons but I'd bet this is a stock motor with bolt ons only. At most maybe a cam and that's it.

This also leads me to believe that a 2.9 stroker SHOULD be able to get a lot more power than 192whp if you did the motor right, If I were to keep my current setup (all the bolt on crap) and put a high comp (10:1) motor combined with a cam there should be nothing stopping the car from getting 225-250whp. Heck a stroked NA m10 can break 180whp so an m20 better be able to 225whp.

[Ray Smoodiver]

Player6 from england's 2.8 is making 250hp at the engine, unsure of a wheel figure.

[winstontj]

This will come off as arrogant and cocky but if I were to build a stroker motor I would think it's not worth it unless I could get 250 to the wheels... IMO 200 to the wheels isn't that much of an improvement over 178 to the wheels.

[digger]

If new stock = 152whp then I would say it's 100% possible to get up to 178whp (my car) on just a few upgrades.

Retail (flyhweel) published numbers:
Chip = 15hp
Split Second Intake & management system = 15hp
Adj. FPR, uprated injectors = 5hp
Exhaust = 5hp (have header & stock so maybe this does not count)

Total = ~40hp (flywheel)

Divide that number in half and you get ~20hp increase which would be reasonable to bring the car up to ~172whp. Factor in variables, running AVGAS for dyno session, car in perfect tune, etc. and I believe that it's possible to get up to 178whp from a fresh stock motor with only bolt on upgrades.

Can anyone toss this argument out the window? I'm going to pull the valve cover this weekend as well as pull the plugs and take a peek at the pistons but I'd bet this is a stock motor with bolt ons only. At most maybe a cam and that's it.

This also leads me to believe that a 2.9 stroker SHOULD be able to get a lot more power than 192whp if you did the motor right, If I were to keep my current setup (all the bolt on crap) and put a high comp (10:1) motor combined with a cam there should be nothing stopping the car from getting 225-250whp. Heck a stroked NA m10 can break 180whp so an m20 better be able to 225whp.

mods don't add up like that.

First you have to prove that it makes 17x rwhp. You won't get a genuine 250whp from a 2.9L, realistically you would have to spend 5-10k just to break 200whp.

[digger]

This will come off as arrogant and cocky but if I were to build a stroker motor I would think it's not worth it unless I could get 250 to the wheels... IMO 200 to the wheels isn't that much of an improvement over 178 to the wheels.

Not arrogant or cocky just in experienced as you will spend alot to get 250whp from a m50/52 or s50/52 let alone a 12V single cam M20 designed in the 70's and 80's. From your recent posts you don't have realistic expectations of whats possible or an appreciation for whats involved. A genuine 200whp will show e36 m3's your tailpipes and make e46 m3 owners think twice about their purchase.

[Andreas]

From what I hear, 6 cylinder M-Power engines (E36 and E46) are in the region of 15-20 hp short of BMW's claims. However I still have a huge amount of respect for the M-Division and believe their engines are extremely well tuned.

Now to think you're going to take an old M20, throw in a crank, some pistons and a camshaft AND then exceed a 3 liter M-motor's output with a 2.9 liter is a bit ambitious.

Maybe not impossible, but even if you do manage to pull it off, there are probably going to be some serious driveability issues under 4,000 rpm.

[PУCCKAЯ_e30ka]

you're not even sure it makes 178... why even talk about if it will make 200+??? go to dyno and see what it makes... then talk

[winstontj]

you're not even sure it makes 178... why even talk about if it will make 200+??? go to dyno and see what it makes... then talk

I have a dyno sheet from four years ago stating 178whp. I only offer that the car does not currently make that because it has been driven daily since then and has not been kept in a decent state of tune since the owner who took the time to dyno the car sold it to the most recent PO.

I come from an m10 background so I will admit that I don't know these (m20) motors inside and out however I do know that with extensive work (ie. stroked crank, pistons, cam, porting, intake, exhaust, CC work, increased CR, etc.) most any BMW motor can yield ~100hp/liter @ flywheel. If a 2.2L M10 can produce 200+ at the flywheel why can't a 2.9L produce 250 @ the flywheel. Yes I'll have to spend ~$5,000(+) on the m10 to get there and possibly $8,000(+) on the m20 to get there but that is a given that money needs to be spent to get to those numbers.

I'm certanly not talking about bolting on parts to reach 250whp.... I'm talking about a full build, stroked motor, pistons, cam, intake, exhaust, extensive combustion chamber work, head porting, valves, etc. The effect of this is you take a 20+ year old motor and produce modern power from it. Anything can be done given time and money - but if a bone stock motor produces somewhere in the 150whp range why is it not possible to get ~200whp from a highly modded NA motor? I'm not trying to start trouble here - I had similar opposition regarding power output of a 2002 m10 motor but now there is a motor to back it up and it's common to see guys with stroked m10's putting 175 to the wheels. If an m10 can put 175 to the wheels (NA) I'd surely hope that an m20 could put 200 to the wheels.

BTW, What do the race/track guys get? I realize that they have to stay within class rules which could possibly exclude them from building a stroker motor but what does the average fully built race m20 motor in an e30 put to the wheels? That will tell all here.....

[winstontj]

mods don't add up like that.

I don't know how mods add up and honestly listing bolt on mods isn't going to get anywhere. I started this thread to try and figure out what was inside the motor I have - I guess I'll pull the valve cover like I said I need to do and see... No idea about how to inspect the crank.

First you have to prove that it makes 17x rwhp.

I scanned the dyno sheet and opened an account for photo hosting. I'll post it soon - To me it's a piece of paper that is part of the car's past. I'd doubt that the car in it's present state of tune puts any more than 160 to the wheels. This summer I'll find a dyno and I'll pay for a tuning session and see what numbers come up again and I will post those as well.

You won't get a genuine 250whp from a 2.9L, realistically you would have to spend 5-10k just to break 200whp.

I assumed that it would cost ~$8,000 to build an m20. It cost me ~$5,000 to build an m10 so it's good to hear you say it'll cost 5-10k to break 200whp. I'm not building a race car and the tires break loose in first, second and third so more power to me is almost foolish. If I can put it on a dyno and duplicate the 178whp as well as figure out a torque number (can't read it on the sheets) then I'll build a stroker aimed at 200whp and leave it at that. If I can spend ~$8,000 and get 200whp I'll be happy.

[Andreas]

Hi winstontj

I am glad that someone is willing to spend some serious money on a M20 motor just to see what can come of it. It will be very interesting to see how your project turns out.

A lot of people on E30 forums like to debate about what is possible with the M20 if you did this ... or what if you did that. Hardly anyone ever tries to do anything serious. The guys that do have some spare cash usually chicken out and install a modern multivalve motor.

So please, stay unreasonable and stay on track with the M20 buildup. I was going to build a high revving 2.8 but was convinced to go 3.1 instead. Hope to still rev it 7,500 rpm though. I would love to compare what can be done with 2.9 vs a 3.1

[winstontj]

We'll see. Money is all relative. I have an opportunity to buy a totally unknown past race s38 and I'm going to pass it up because of the expense. m20 looks cheap once you start looking at BMW multivalve motors :-)

I'm looking (passively) for a motor now to use as a build platform. I may go 3.0L but probably will stay 2.9. I'm still learning (as if you didn't know) so there will be many more questions. Megan and I chose this e30 because I want an e30 as my DD until we have kids and need two 4-doors. Until then I'll be building my 71 2002 and will start an m20 build ASAP.

I am quite confident that a 2.9L with the right amount of work (hopefully in the $8,000 range) and a modern engine management system can come VERY close to 200whp with a single plenum intake manifold (single TB). As you say though... there is only one way to find out.

Things I need to learn more about is exactly what cams produce what power bands, what size valves do you guys run (+1 for both intake and exhaust??), do you guys knife edge your cranks, run windage trays, dry sumps????, distributorless ignition systems, convert to manual steering racks, etc.

I'll figure it out and find a suitable motor shortly....

[digger]

We'll see. Money is all relative. I have an opportunity to buy a totally unknown past race s38 and I'm going to pass it up because of the expense. m20 looks cheap once you start looking at BMW multivalve motors :-)

I'm looking (passively) for a motor now to use as a build platform. I may go 3.0L but probably will stay 2.9. I'm still learning (as if you didn't know) so there will be many more questions. Megan and I chose this e30 because I want an e30 as my DD until we have kids and need two 4-doors. Until then I'll be building my 71 2002 and will start an m20 build ASAP.

I am quite confident that a 2.9L with the right amount of work (hopefully in the $8,000 range) and a modern engine management system can come VERY close to 200whp with a single plenum intake manifold (single TB). As you say though... there is only one way to find out.

Things I need to learn more about is exactly what cams produce what power bands, what size valves do you guys run (+1 for both intake and exhaust??), do you guys knife edge your cranks, run windage trays, dry sumps????, distributorless ignition systems, convert to manual steering racks, etc.

I'll figure it out and find a suitable motor shortly....

the cam is one of the most critical parts to consider, too much cam will kill bottom end for little gain up top. The cam used should compliment the CR so a high CR can use a big cam but low CR (read alot less 10) with a high duration cam will anihilate bottomend its mostly to do with dynaimc compression ratio opposed to the static compression ratio normally quoted. Also there is more to a cam than duration so all 272 are not equal.

+1 valves intake will gain some but exhaust is a waste really you'll never feel it except in the wallet and gains from this will be all mid to topend.

There are many many more important things to do/purchase before knife edging or windage trays are considered.

Don't chase rwhp it doesn't really give a true indiation of how a car will perform.

[winstontj]

the cam is one of the most critical parts to consider, too much cam will kill bottom end for little gain up top. The cam used should compliment the CR so a high CR can use a big cam but low CR (read alot less 10) with a high duration cam will anihilate bottomend its mostly to do with dynaimc compression ratio opposed to the static compression ratio normally quoted. Also there is more to a cam than duration so all 272 are not equal.

+1 valves intake will gain some but exhaust is a waste really you'll never feel it except in the wallet and gains from this will be all mid to topend.

There are many many more important things to do/purchase before knife edging or windage trays are considered.

Don't chase rwhp it doesn't really give a true indiation of how a car will perform.

The thing is the car is already done - suspension... shocks, springs, bushings, sways, strut bars

I'm not out for 300000rwhp I simply want to be at a certain power to weight ratio so whether its' a bhp or whp number it's only a small increase that I'm after. This car will will take me to many driver's education courses and I'm going to start racing an itb/c prepped 2002 this season so I don't need a race car - just a little fun off the track. dodging cones isn't for me so it is simply just to have a little fun. I'm after low end power more than peak HP. I think when I'm done (12months) you'll be suprised at the power curve I end up with. Ideally it'll go straight up to 200whp, stay there from 2,000 up to 7,000 and then who cares from there - LOL... we can dream right???

[SA E30]

Hi winstontj

I am glad that someone is willing to spend some serious money on a M20 motor just to see what can come of it. It will be very interesting to see how your project turns out.

A lot of people on E30 forums like to debate about what is possible with the M20 if you did this ... or what if you did that. Hardly anyone ever tries to do anything serious. The guys that do have some spare cash usually chicken out and install a modern multivalve motor.

So please, stay unreasonable and stay on track with the M20 buildup. I was going to build a high revving 2.8 but was convinced to go 3.1 instead. Hope to still rev it 7,500 rpm though. I would love to compare what can be done with 2.9 vs a 3.1

I hope u not coming to pick on me :P

but, I would like to see what a 2.9lt with similar specs to what your 3.1lt would do compared to the 3.1 ... only time will tell :D

[nando]

We'll see. Money is all relative. I have an opportunity to buy a totally unknown past race s38 and I'm going to pass it up because of the expense. m20 looks cheap once you start looking at BMW multivalve motors :-)

I'm looking (passively) for a motor now to use as a build platform. I may go 3.0L but probably will stay 2.9. I'm still learning (as if you didn't know) so there will be many more questions. Megan and I chose this e30 because I want an e30 as my DD until we have kids and need two 4-doors. Until then I'll be building my 71 2002 and will start an m20 build ASAP.

I am quite confident that a 2.9L with the right amount of work (hopefully in the $8,000 range) and a modern engine management system can come VERY close to 200whp with a single plenum intake manifold (single TB). As you say though... there is only one way to find out.

Things I need to learn more about is exactly what cams produce what power bands, what size valves do you guys run (+1 for both intake and exhaust??), do you guys knife edge your cranks, run windage trays, dry sumps????, distributorless ignition systems, convert to manual steering racks, etc.

I'll figure it out and find a suitable motor shortly....

IMO all that extra crap costs a lot more money and isn't going to get you much. maybe a crank scraper (just because it'll help with potential oiling problems on a track), but the rest isn't going to make any difference that you'll be able to notice.

I think with an 86mm bore and 84mm stroke, you should easily be able to break 200whp. I've said it before but jordan had a pretty mild cam (272) and he had the base stroker dimensions - 81x85. also because of his piston design (I think they were IE) he had to retard the timing a whole bunch just to get it to run. he did have the car fully dyno tuned with long tube headers though which is probably why he made more power than almost everyone else who has done this.

spend your money on a good bottom end build using the lightest parts you can afford (the 84mm crank is forged and it's already lighter than the stock one, so that's a start). The rest is in the headwork - arguably the most important part, especially for us 12v guys. I still think that wanting to make power at 7500rpm is a waste of time - I usually don't rev past 6500, it doesn't make much power past anyway there and the meat of the torque curve is between 2000 and 6000rpm. Focusing on a broad torque curve and smooth revs will probably be much more satisfying than an elusive and ultimately useless peak #..

FYI I think my motor cost about $8k. I don't think I have 200rwhp tho :p

oh yeah, I'm really a believer in the schrick 284/272 cam.. I originally put it in my car stock, and I actually *gained* low end torque (butt dyno), plus in the high end it just screams. the idle is still smooth enough for a DD as well.