m20b25 power

[Bav///Motorworks]

wut does the stock m20b25 put down to the wheels stock? around 135whp? i'm gonna be sending out an extra set of cam to get regrounded to 272 by IE, full length header, highflow cat and custom single pipe 2 1/4 exhaust, a chip, m30afm w/ 19lbs injectors. how much hp will i be looking at to the wheels or crank? hopefully 150whp but i highly doubt that, cost an arm and a leg to get power out of the m20 without goin FI, but i love bmw motors n/a.

[browntown]

if you're spending that kind of cabbage it would behoove you to dyno baseline, and dyno as you add your new toys. I wouldn't trust any manufacturer number for any one mod and then try to claim a HP number. Your expectations are realistic, but these are old cars and I encourage you to make sure the money is worth the increase by using a dyno to find the digits you seek.

[X2theZ3]

why are you sending a set of cams to be grounded?

the m20 only has 1.

[blueapplesoda]

he said sending out "extra set of cam"

LoL it stupidly makes sense, maybe meaning his extra cam


I heard somewhere on this forum a healthy m20 will put around 140-150 to the wheels, but I am not 100% sure..

bav///m how much are you payin IE to regrind? im thinking about doing that since I am bulding an n/a m20.

[RobertK]

I wouldn't think that a cam regrind or a more agressive cam would give you that much extra HP. Usually people get more agressive cams so they can achieve more torque at lower RPM. From what I understand that's what most cams are good for.. changing your torque curve.

[silversleeper]

u guys shoulda just hopped on that catcams gb...

i really just want a super aggressive cam so that my car struggles to hold a steady idle. thats hawt!

[nando]

a 272 regrind isn't exactly an agressive cam..

[Van Westervelt]

a 272 regrind isn't exactly an agressive cam..

Yeah a 272 is pretty much as mild as you can go without going stock.

[pdx 528e]

I wouldn't think that a cam regrind or a more agressive cam would give you that much extra HP. Usually people get more agressive cams so they can achieve more torque at lower RPM. From what I understand that's what most cams are good for.. changing your torque curve.

I thought the point in most cases was to bring the torque up higher in the rev range to produce more power. The eta cam (234 degree?) does the whole low rpm torque thing, which hurts the power

[nando]

a cam with more duration and lift (you are only getting duration with a regrind) will flow more air into your engine, which = more power and torque. it also moves the power band further up into the RPM range because of the increased airflow - at lower RPMs, the velocity will be lower than at higher RPMs. you aren't going to lose much if any low end torque though on a decent cam, and you will gain both power and torque higher up.

if you really want more power, go with a dual pattern and forget about regrinds. the difference between the lobes of my schrick 284/272 and my racetep 284 (supposedly "new" grind, but obviously a regrind) was laughable. I think catcams offers a dual pattern as well for a decent price - maybe it's not too late to get into that group buy.

[pdx 528e]

a cam with more duration and lift (you are only getting duration with a regrind) will flow more air into your engine, which = more power and torque. it also moves the power band further up into the RPM range because of the increased airflow - at lower RPMs, the velocity will be lower than at higher RPMs. you aren't going to lose much if any low end torque though on a decent cam, and you will gain both power and torque higher up.

if you really want more power, go with a dual pattern and forget about regrinds. the difference between the lobes of my schrick 284/272 and my racetep 284 (supposedly "new" grind, but obviously a regrind) was laughable. I think catcams offers a dual pattern as well for a decent price - maybe it's not too late to get into that group buy.

Lift is the difference between the highest point on the lobe and the base circle. A proper regrind, with properly adjusted eccentrics should produce the same lift as a new cam. I'm sure there are limitations for how much material can be removed before the eccentrics/rockers cannot compensate.

What constitutes a dual pattern, differing intake and exhaust durations? What kind of improvements do these make?

[SpecM]

-OK... so what does a healthy m20b25 put to the wheels?

[modifiede30]

Don't forget the oversized eccentrics you'll have to buy (around $100). I'd invest in a fresh casting and not go with a regrind. I've been there and it just isn't worth the money. I have a used 274 if you want to buy one that's been reground cheap to test, but that's a lot of work to install only to have it suck.

[yozsi]

Lift is the difference between the highest point on the lobe and the base circle. A proper regrind, with properly adjusted eccentrics should produce the same lift as a new cam. I'm sure there are limitations for how much material can be removed before the eccentrics/rockers cannot compensate.

What constitutes a dual pattern, differing intake and exhaust durations? What kind of improvements do these make?

btw, when they regrind, they actually add material to the stock camshaft.

[Erisa_1974]

-OK... so what does a healthy m20b25 put to the wheels?

150rwhp. that's real strong

several have seen that with a chip though