Getting the most from my m20b27

[general246]

i know its probably been answered several times but i just want to know if anyone has any more ideas of how to put more power down. any other info would be greatly appreciated as ive done alot with the car
current mods:
fully rebuilt 325i head(ported & polished)
2.7 bottom end rebuilt
25# mustang injectors
turnermotorsport chip
3.0 k&n
str8 pipe to stromung exhaust
3.73lsd for now( 4.10lsd waiting on nice weather to drop her in)

parts on the way:
shrick cam
pulley set

my goal:
to beat e36 m3's
i thrash on 325is/8is by like 1-2 cars

any other ideas would be appreciated once again.

[MR 325]

Those injectors are retarded big. Put some 17 or 19 in there. Are you using an i harness and computer?

To beat an E36 M3 you better start shopping for turbo parts. That motor definitely won't do it N/A.

[DmcL]

inlectors are larger than required tho if they are tuned for correctly then it wont matter.

for more gains i would suggest a custom tune for ur specific engine and not an off the shelf chip, if there are no motronic tuners near u that can do it then its either going to have to be generic off the shelf chip or go standalone. also with the headwork done u might benefit from a BBTB or having the stock TB bored out (can only take the B25 TB out to 64mm ID, any bigger and u start coming out the other side), also a larger AFM like the M30 unit or a MAF or something (will require different tune or standalone tho).

once u throw the cam in there it may show just how much u could use a custom tune.. even on the setup as it is u can get more power from a more agressive tune but the only way to get one would be a motronic tuner or standalone.

[Pussy30]

Your gonna be running out of gears scary fast in a b27 with a 4.10

[DmcL]

but it will be a fun run to the limiter in 5th tho lol

[Pussy30]

but it will be a fun run to the limiter in 5th tho lol

Ive done it with a chipped b27 and 3.73

Just sucks for cruising.

[general246]

inlectors are larger than required tho if they are tuned for correctly then it wont matter.

for more gains i would suggest a custom tune for ur specific engine and not an off the shelf chip, if there are no motronic tuners near u that can do it then its either going to have to be generic off the shelf chip or go standalone. also with the headwork done u might benefit from a BBTB or having the stock TB bored out (can only take the B25 TB out to 64mm ID, any bigger and u start coming out the other side), also a larger AFM like the M30 unit or a MAF or something (will require different tune or standalone tho).

once u throw the cam in there it may show just how much u could use a custom tune.. even on the setup as it is u can get more power from a more agressive tune but the only way to get one would be a motronic tuner or standalone.

the motor is actually turbo ready but i feel like having some fun w/ n/a for now as i just had +1 added to the fam so turbo plans on hold for now. but i denifitely need a custom tune after a little more mods.

Those injectors are retarded big. Put some 17 or 19 in there. Are you using an i harness and computer?

To beat an E36 M3 you better start shopping for turbo parts. That motor definitely won't do it N/A.

....
yup, i harness and computer just chipped and i should of been specific as i mean beating e36 m3's from 0-65mph that is y i had the 4.10 in mind and i was about to down grade to slightly smaller 21#...i also racedmy boys e36 m3 w/ only a dinan cold air intake and he only beat me by half a car from 0-60 few days ago

Your gonna be running out of gears scary fast in a b27 with a 4.10

true but the 4.10 was for city accel. but i love the 3.73 in there rite now.

[DmcL]

ah well id say bite the bullet and got aftermarket on the management. far more support for megasquirt or similar. theres a huge thread of timing/fuel maps on M20's over on e30tech, alot of the info is from boosted M20's also and alot of it is with megasquirt.

if u happened to have a motronic specialist next door that would be about the only time id recommend sticking with tronic..

[ForcedFirebird]

Your car will be running amazingly rich with 24lb injectors. With stock i injectors, fresh 885 top end, 2.93 gears, stock chip, stock eta exhaust, stock eta manifolds, stock airbox and my car made 134whp/145wtq with the AFR's approaching 15.5:1 (see vid in sig).

Later I tuned it and brought it back to the dyno, but had an issue with the keyway on the crank that retarded the cam and ignition timing - but the curve was amazingly better. After the new head gasket, tuned correctly with the proper top end timing, and added compression am quite curious to see what the new numbers are.

The head is about to come back off and am replacing it with a .051" MLS gasket that should get the compression back to about 9:1 as the 2.7 should see, but with the stock gasket you are around 80-90psi cranking pressure which is wayyyy to weak N/A to make enough power to smoke an m3.

Also, don't do the 4.10's, went that route myself and found it being a pain to shift before you reach the middle of an intersection. The engine will feel torquey and longer gears just feel better all around IMO. I had no problem keeping up i cars and leaving ones that were even slightly tired with my 2.93's vs their 3.73 third members. A 4.10 feels like you have half a first gear lol.

Just picked up a 3.73 (2.93 back in now), also curious to see how it feels seeing the 4.10's were a mistake on the 2.7i.

[DmcL]

hmm.. im making 133whp, dyno reckons its 152.6bhp tho? book figure on these is 168-171bhp. think the bhp calculation might be off on the dyno or something? im making tons of torque but not so much HP.. maybe fouled/glazed plugs cause i tried advancing and retarding timing as well as adjusting AFR lean/rich with no real change, was all within like 3bhp and 3lb/ft ish nomatter what i did. same with/without M30 AFM also...

theres a physical limiting factor here.. need to figure out what tho. was thinking i maybe put a 320i cam in by mistake but even if i did it shouldnt have dropped HP. peak torque figures are bang on book figure but peak HP is below oddly.. have a +4mm BBTB (M30 AFM on the dyno day also), stock catless system and scorpion backbox (muffler), NGK copper core plugs, good ignition system thats mostly new (plugs maybe coming up on 2yr old), good fuel system with lots of new parts, compression was ok last year and its not burning any fluids or using any fluids or running in any way out of the ordinary apart from seemingly low top end..

very strange issue if the dynos calculation wasnt off.. only think i can think of is fouled or glazed plugs but id think there would be general driving/running issues associated with that.car does have trouble starting if it sits for over 13 hours sometimes but i was thinking that would be battery/alternator since it started during a cold snap here where we got freezing weather and i was driving to/from work with lights, heater, rear screen de-mister on all the time.

[nando]

your engine is just old. 133hp isn't that unexpected from an original M20, even if it does have some work.

what's the curve look like?

[DmcL]

im waiting on them to email me a copy of the graph. when i saw 152bhp i didnt even bother getting it printed just asked the WHP for reference. wish i did now just to compare with other dyno graphs.

thing is that was on a hot tune also, it wouldnt even pull on the stock tune oddly.. i went as far down as i could to stock and that gave 148.something BHP. torque curve was dominating the graph tho, it was like a huge mountain peaking in the middle with a fairly uniformed rise/fall on either side of the peak and then peak HP was this little fart bubble on the tail end of the falling torque curve.. like just enough to say "hey im over here" lol

the engines healthy and quite alot of parts on it are new.. it should be making more unless maybe the copper core plugs have worn or theyre fouled or have high speed glazing but like i said no running issues bar cranking with eventual or no start if the car sits for long enough.

mods wise its essentially stock really just the 64mm bored out stock TB, M30 AFM and arguably scorpion backbox, also some 16lb @ 3 bar E36 325i injectors but the tune is set for them and AFR runs around 12.5 at WOT and i run it a bit lean at part throttle/lower load (around 15-16 AFR). have a pattern part new rear section and backbox to go on as well as picking up another stock airbox to put back in just to see if theres any change going back to stock intake/exhaust wise.

i have to replace the fuel tank and im doing some of the brake hard lines up above the subframe/tank while the tanks out and maybe also powerflex rear subframe bushes. i have atleast 1 aftermarket cam with my name on it, the guy has 2 but so far has only found 1 of them. we think the 1 he found is a kent cam and he thinks the other is a schrick. will be fun doing the timing belt and all that again whenever i get 1 or both of the cams, only did the belt like 15k ago.

EDIT: also FWIW, i seafoamed the engine doing the 1/3, 1/3, 1/3 method in oil, breather and fuel. didnt smoke for more than about 1-2 minutes after seafoaming it. i even went back and used a little that was left over to hit the engine via the breather a second time and same again. probably my lead feet burning all the carbon out of it even without the seafoam. wasnt really much if any difference before/after seafoaming, maybe slightly better after but barely..

[general246]

damn u guys held a whole discussion while i was gone huh......at least u really kno ur stuff....thanks for the info and the wisdom as well....picked up a m30 afm from my buddy so i'll c if i feel difference but im really excited to c my cam when it gets here.....any of u ever lined up against an e36 m3 with those mods??...result...??

[ForcedFirebird]

your engine is just old. 133hp isn't that unexpected from an original M20, even if it does have some work.

what's the curve look like?

Right. Everyone flamed me for making 134 with my 2.7 and low compression.

Here's the all stock parts graph...



and the tuned graph, added 2.25" exhaust after eta merge pipe - numbers omitted, obviously, will release dyno results after back to back consecutive runs (90k mile bottom end)...