Why is the E motor slow?

[McCoolidge]

I have an m20b27 and what i was thinking was that it is a 2.7 liter engine, in my experience that is pretty big for a german car and for what i want to work with. My question was that why is the b27 slow? is it cams? programming? what would be stopping me or have to be changed to make somewhere around 300hp? I would like to keep it N/A.

[Axxe]

No way are you going to make 300 hp out of a N/A M20 based motor and have any sort of reasonable service life. Slap an "I" head on it, arp studs, and turbo the sucker.

[backtrail69]

You are lacking a good head, intake, EMS and exhaust. The whole head is pretty much garbage and chokes the engine down to 4500 rpms. The intake manifold is not as good as the I motor and the EMS is alot more primative. Also the exhaust is much more restrictive compared to the I motors. This all inturn creates a torquey motor that chokes up high in the RPMS. You will also NEVER make 300 hp out NA unless it is a 24v engine... 2v per cylinder really chokes this motor.

[Jand3rson]

It's "slow" because it was detuned for higher torque and better fuel economy, thus having less horsepower and and a lower rev-range. The runners of the intake manifold are skinnier to produce more torque, and the throttle body is also smaller. The head has only one set of valve springs compared to the 325i's dual valve springs, and the cam is a different profile. The pistons are a different design at the top, and the rods are a different length to increase the stroke and create a 2.7L engine. It also has different engine management. A 325e benefits IMMMENSELY from an aftermarket chip, JimC, MarkD and a few others are the best bang for the buck. And if you want to get more in-depth, the 325e head only requires a little machine work and a few parts to make a dramatic improvement. The dual 325i valve springs are a direct fit, and you can also fit a 325i cam by having 2 additional oil journals drilled in the head. If you want to take it further, you can have the intake and exhaust ports enlarged slightly, and also have a valve grind done. Going even farther, you can fit the intake manifold and throttle body from a 325i, as well as the entire wiring harness and engine management system, and build a cheap 327i.

[McCoolidge]

Yeah i meant around 200hp, I am going to look for an i head. So, basically if i do:
Headers
Exhaust
Head
ECU
Intake
then I should be closer to the 200 goal?

[nando]

the skinny runners aren't what produces the torque.. it's the extra length of the runners. skinny runners are a restriction no matter how you look at it. also, the rods don't increase the stroke, that's the job of the crank.

pretty much the only thing worth keeping if you want to build a high HP m20 is the crank.. the rest of the motor is pretty much garbage. if you don't want to mess with internals just do what eurospeed said and get a chip.

[Slick92GS-R]

as mentioned b4-- for performance, the 2.7 is not what u want. u are much and i mean MUCH better off with the i motor.. they are cheap enuff to swap out and plentiful in any junkyard and its a realtively easy swap...
..what limits the 2.7 is the low compression, cam & head design. ETA's traditionally also come with a 2.93 gear ratio with further hampers perfomance (n/a at least) ..bolt ons w/a M20? with an i motor, cam, 19lb injectors, chip, flywheel, nice header good exhaust.. maybe 170 to 175 WHP .. these cars are simple enuff to turbocharge-- will cost $1200 to $1700 for a dependable set up for 275 whp. finding a tuner will be your biggest challenge.

set a realistic goal, watch your $$$ and go for it !!

[McCoolidge]

I am going to the junkyard next week to pull an I motor to rebuild. So this may be my fun motor. No more ETA!!!!

[SA E30]

No way are you going to make 300 hp out of a N/A M20 based motor and have any sort of reasonable service life. Slap an "I" head on it, arp studs, and turbo the sucker.

Uhum... I beg to differ.

Friend of mine is busy with this.

3.1lt Metric Mechanic Stroker (bottom end)
302 deg shrick cam
48mm ITB's with CF Plenium, custom designed adaptors.
Big Valves, Gasflowed, 5 angle valve seat.
Ireland engineering 9000rpm rockers, Shrick Valve springs and titanium retainers.
Motec management.
Meth Injection

Gonna rev it to about 7500rpm.

He's lookin at 300hp.

in a 1000kg e30 (well approx) , got CF fenders (M3 style) ... and fully stripped out. ( I know there is other stuff going into making it light weight.

With the amout of money being spent on this car... I'm pretty sure it will make it's mark.

[92 mtechnic cabrio]

No way are you going to make 300 hp out of a N/A M20 based motor and have any sort of reasonable service life. Slap an "I" head on it, arp studs, and turbo the sucker.

money money money will make anything possible, never say never, although I gues you never did say never.

:drink:

[Borat]

..what limits the 2.7 is the low compression,

actually the eta has higher compression than the i motor, its whats givs it some of its efficiency.

[matt]

Uhum... I beg to differ.

Friend of mine is busy with this.

3.1lt Metric Mechanic Stroker (bottom end)
302 deg shrick cam
48mm ITB's with CF Plenium, custom designed adaptors.
Big Valves, Gasflowed, 5 angle valve seat.
Ireland engineering 9000rpm rockers, Shrick Valve springs and titanium retainers.
Motec management.
Meth Injection

Gonna rev it to about 7500rpm.

He's lookin at 300hp.

in a 1000kg e30 (well approx) , got CF fenders (M3 style) ... and fully stripped out. ( I know there is other stuff going into making it light weight.

With the amout of money being spent on this car... I'm pretty sure it will make it's mark.

7500RPM M20 = not a reasonable service life. I give it 20k.

[digger]

7500RPM M20 = not a reasonable service life. I give it 20k.

Yes, the ti retainers may just give this life. i would see ppf for some uprated steel ones (or aluminium ones that last 3k) but you have to use their uprated springs and you won't get the same weight savings though. Stay away from ti retainers for the street IMO however this SA car doesn't sound like it will be a daily driver. Also MM have a single progressively wound valve spring good for 8000rpm which saves weight on the springs and retainer (much better savings than ti retainers). Bigger valves will kill any savings from using of ti anyway so go for strength