Browse › Tech ›What the hell is that?

What the hell is boost creep

Started by Indecisive · Jun 11, 2004 · 2postsSMF 2010–26vBulletin 2004–05

Indecisivedate not saved · #1

Posted by Magnum

Boost Creep
A turbocharged car is a positive-feedback system. The faster the turbo's compressor wheel spins, the more horsepower the engine makes. More horsepower means more exhaust gasses are being expelled. The more exhaust that is expelled the faster the turbine (and thus the compressor) wheel spins, and so-on until the engine explodes.

The ECU (sometimes via a boost controller) controls the boost level by opening the wastegate. Boost creep, in which the boost level of your engine continues to rise despite the best efforts of the wastegate, is caused when a fully-open wastegate can't divert enough gasses around the hot-side turbine wheel.

Boost creep can usually be eliminated by porting the wastegate opening and O2 sensor housing or by using an external wastegate. Both of these allow exhaust gasses to vent more efficiently.

IndecisiveJun 11, 2004, 3:25 am · #2

[span style=\'color:red\']Posted by Magnum [/span]

Boost Creep
A turbocharged car is a positive-feedback system. The faster the turbo\'s compressor wheel spins, the more horsepower the engine makes. More horsepower means more exhaust gasses are being expelled. The more exhaust that is expelled the faster the turbine (and thus the compressor) wheel spins, and so-on until the engine explodes.

The ECU (sometimes via a boost controller) controls the boost level by opening the wastegate. Boost creep, in which the boost level of your engine continues to rise despite the best efforts of the wastegate, is caused when a fully-open wastegate can\'t divert enough gasses around the hot-side turbine wheel.

Boost creep can usually be eliminated by porting the wastegate opening and O2 sensor housing or by using an external wastegate. Both of these allow exhaust gasses to vent more efficiently.