Just Dyno'd my 98 2.5 986 with supercharger

[Aus986]

The motor is pretty have ing done only 70klms that's like 45k miles which i think gives it some chance of survival.

From what I am hearing the reason the motor would blow is only if you don't change the exhaust and inlet

???

confused

Aus986

[Topless]

The enemy is heat... and your right foot. Keep it off the rev lim. and enjoy the ride.

[insite]

Originally Posted by Topless

The enemy is heat... and your right foot. Keep it off the rev lim. and enjoy the ride.

in this case, the enemy is the cylinder pressure. the boxster already has a high compression ratio. add to that pressurized induction. now add to that a free exhaust and intake. now add to that an intercooler. all of this translates to way more air, which means way more fuel, which means way higher combustion pressures. you would essentially be burning over 50% more fuel per revolution than the motor was designed to handle. the motor internals are not sized to handle this.

if you replaced the pistons with a low compression variety, you'd probably be okay. with stock compression, you are going to blow a hole in a piston or snap a rod. it doesn't matter if your car has 45,000 miles, 145,000 miles, or zero miles. if it's overloaded, it's going to break. you absolutely are going to blow your motor.

what you need to do is ensure you have the stock intake, stock exhaust manifold, and stock supercharger pulley. contact the manufacturer of the supercharger system; they will verify this.

[Gary in BR]

I am by no means a mechanic but by just installing a supercharger and doing months of research I say 7.5lbs is more than any company is selling, I do know of a guy in Melbourne FL who uped his boost to these levels and he did blow his engine.

Did you get the chip reflashed? or add a extra fuel injector? I would track down the kit maker and contact them. If you post who made it I am sure someone here can point you in the right direction.

I really hope the best for you and I promise all of us want you to get the most power you can but with out blowing an engine.

Gary

[insite]

Originally Posted by Gary in BR

I do know of a guy in Melbourne FL who uped his boost to these levels and he did blow his engine.

that was trent

[Gary Gaukler]

I find it hard to believe that your car makes 270 hp at the wheels at 7.5psi. 7.5psi is a 51% increase in pressure over atmospheric; 270hp is approx. a 50% increase in rwhp (180 vs. 270). Hence either your supercharger is 100% efficient (which is impossible), or there are some huge gains in volumetric efficiency (which is unlikely). Maybe it's 270 at the flywheel? Even that would seem high...

Apart from this, I echo the comments made by others that unless internal changes have been made to the engine, it is likely to blow up soon at 7.5psi. Adding an exhaust or an intake is not really going to change that.

Best of luck (and I don't mean this in a facetious way)!

Gary

[Aus986]

yea
the kit runs an extra injector.

have pulled the boost to gimme around 240

apparently the suggestions are get it breathing and try to keep it at 240hp at the rears ans it swhould be fairly safe

Aus986