325i internals?

[Millar]

what sort of pressure and bhp under forced induction can you get out of an e31 325i engine before you need to change the internals?

[Madhatter]

as you head towards 300hp at the wheels seems to be about the point when stuff tends to breakdown and people have issues. So you are probably talking in the region of 350hp at the motor. Everything starts to have issues there, rod bolts letting go, head gaskets blowing, even rings, a bit of a mixed bag as to what might fail. Motors are getting on in years, cant expect them to last for ever

[e21-Mark]

Mosselman used to supply a low pressure turbo system designed for use with a stock 2.5. I think it was about 8psi and gave 230 - 240bhp iirc. There's plenty of stuff to read on the subject on e30zone.

[Millar]

Yeah i was looking at turbo kits and most of them said to run about 8psi on a stock motor. think i might go for it, got to love the sound of a turbo

[murran]

thats what i thought, but disposable cash is no where to be seen in my household!
im saving for the engine management atm. while trying to get the cheap bits and bobs needed.

[Millar]

really want to get one, but postage from the US is sooooo much its ridiculous... still its got to be worth it

[tommi_e21]

boosting a stock engine is just false economy.

from the factory new its fair to say mossleman and these other companys could just bolt a turbo and run 8 psi without doing much else but it just isnt good.

your prob better off turboing a 323i on kjet and fitting a turbo metering unit of something and atleast the 323i runs lowish compression and you can jack loads of fuel into it and mess around with the timing fairly easily.

its not so much the limit of power that the engine can take its more about the way the power is fed to the engine. eg if you have a massive turbo which has about 50 bhp at 2500rpm then 400 at 3000rpm the torque change will break shit, if your fairly sensible then it wont.

for drifting i would suggest making everythin strong, you will be mashing the pedal all over the place

[Millar]

hmm, just gonna see how much i can get out of N/A 2.5i first and see how well that drifts

[tommi_e21]

as long as the diff is welded and you have sparre driveshafts she will go sideways all day long!!! make sure your handbrake works and you got a decent steering wheel and decent gear shifter

[Millar]

yeah i should probably start collecting some spare driveshafts. need to adjust the handbrake, get a dishy wheel and get a shortshifter anyways, so it will all be getting done