Hi there. I know a guy who modified only intake, exhaust(downpipe, midpipe, catback). Is he running too lean if he has no EMS? The fuel management is stock. How much boost over stock does the turbo produce without cats?

Thanks!

he probably is running lean and overboosting if he has no cats. he is gonna blow his car up.

he should get a Power FC. shouldn't he?

he should get a Power FC. shouldn't he?[/quote]

With a FULL exhaust, yes he will definitely need some type of engine management...preferrably a PFC.



I guarantee you that within a year, his engine is blown. https://www.nopistons.com/forums/pub...IR#>/boink.gif

If he is only running stock boost; 10psi, he'll be ok. The stock computer can handle an open intake and exhaust as long as you're not also running high boost. It's adviseable that he get a computer like jspec said, but it isn't necessary. But it IS adviseable.

But wouldn't be a simple Greddy fuel cut controller enough for him? The boost is raised only minimal by replacing the cats

No because without the cats the exh flows to freely and will cause the turbo to overboost more often. When that happens the computer can't supply enough fuel. Also the fuel cut defenser only tricks the computer into thinking the car is only boosting to the stock settings. When that happens the computer is only putting enough fuel in for the stock settings which will cause it to lean out more because he is boosting above stock.

the fd ecu will handle any mods up to the factory fuel cut, after that you need a power fc



mike

can anyone tell me how much the boost is raised when using a full exhaust?

full exhaust expect spikes to 15+ psi........