So...I have an 03 WRX. I have the Vishnu Stage Sub-Zero (re-mapped ECU). THe turbo doesn't spool up , as you know, until 3000RPM. At 70 MPH, it is only at about 3500RPM. Redline is about 7000RPM. So....If i am driving at 4500-5000RPM, is that bad for the car, or is the WRX made for that?

Am I ruining the engine?

 

Its fine to rev the motor up to 5k+ rpm on acceleration, but when cruising you should keep it around 3k. Just keep in mind that the harder you drive your car the faster it will wear out. The motor will most likely outlast your tranny, so make sure you shift smoothly on those high rpm shifts.

 

The boost is regulated by throttle pressure, not by RPM. You can in fact drive at 5,000 RPM and be on vacuum (negative boost, wastegate open). Your ECU does not turn on boost until you have the gas down 3/4 of the way, and you won't get anywhere near full boost until you have your foot flat to the floor, which means you are accelerating, not driving steadily.

I suggest learning a bit more how turbo engines work -- that's not a "flame," I'm serious; the more you know about how the car works, the better you will drive it and make use of the strengths and weaknesses. www.howstuffworks.com has many excellent engine-related articles. Second, install a boost gauge. You will see immediately that boost is NOT connected to RPM, it is connected to throttle. You are generating *slightly* more power at 5,000 RPM than 3,000 RPM at a constant speed, but not enough power to warrant the extra wear and tear you are doing to your engine, drivetrain and differentials.

 

I wouldn't drive between 4.5-5k everytime you drive the car, just because it kills the gas mileage. The only reason why you would need to drive so high in the revs is if you don't have enough power to push the car along.

Sometimes, when I just want to play with the revs, I would let my car rev as high as 5 and not be in boost. It doesn't wear the motor down as much as it being in boost, but you also don't have as much power.