any idea how much power im making...?

[alpinee30m50]

My m50 in my e30 is more or less stock, but i have headers some no name short ram intake and soon to have 2 inch straight pipes out to a cherry bomb. any idea what kinda power im gonna be making?? im hoping for over 200 at the wheels but i could be crazy...

[dashboardmonkey]

You are crazy.

Search the 24V section to veiw others results.

[nando]

My m50 in my e30 is more or less stock, but i have headers some no name short ram intake and soon to have 2 inch straight pipes out to a cherry bomb. any idea what kinda power im gonna be making?? im hoping for over 200 at the wheels but i could be crazy...

uh, yeah. I bet 165 at the wheels.

and 2" is too small, or do you mean dual 2"?

[alpinee30m50]

165 at the wheels from an e36 m50b25?? i thought it would be more than that lol. My buddy pulled almost 200 with a few mods. I dunno if im doing single or dual yet. If i do single probably three inch

[jlevie]

An M50B25 is rated for 189hp at the flywheel, so somewhere around 160-165hp would be a reasonable result at the rear wheels. A free flow exhaust might bump that to around 170-175hp, but the intake will do essentially nothing.

[alpinee30m50]

oh alright i didn't realize it lost that much power through the drivetrain. I knew it lost some but i didn't know how much. Excuse me for being a dumbass. I do however know that the intake really won't do shit. Im not a riced out civic driver that thinks my intake gives me enough power to have the right to rev on anything that moves.

[AndrewBird]

Generally you lose ~20% of your power from drivetrain loss.

[alpinee30m50]

got it. thank you for informing instead of flaming....

[Adrian_Visser]

I think dynos take off like 18 percent for rear wheel drive cars and about 15 for front wheel drivers.

[nando]

I think dynos take off like 18 percent for rear wheel drive cars and about 15 for front wheel drivers.

They don't take it off, they add it. Power is measured at the wheels and then a "general" correction factor (like the rule of thumb you mentioned) is used to guess crank HP and stroke egos.

it depends on the dyno, but really, it's all bogus. You can't calculate crank HP without knowing the *exact* drivetrain loss, and the only way to do that is by taking the engine out and dynoing it at the crank and then measuring the difference at the wheels.

the best part is if they want you to feel better about what imaginary crank HP number you are making, they just increase the drivetrain loss. a RWD E30 is probably closer to 15%, but they will tell you 20% because it makes you feel happier that your 168whp car is supposedly making 210 at the crank, when in fact it's probably 15hp less than that. ;)

the only thing that matters is WHP, and of course actual trap times. :)

[alpinee30m50]

yeah. im not some dyno queen i could care less how much i have at the crank its all about at the wheels. Of course the less you through the drivetrain the better...haha. I would rather know low numbers and be pleasantly surprised if it pulls more than have someone try to make me feel better about my gutless car and be disappointed later on..