doctor1974 wrote:Hi, Can someone please explain what ``overboost`` actually is and why would this occur from upgrading the exhaust system and how would i know if it was doing this? Cheers
Overboost is a sustained period (8 seconds has been suggested) where the boost is higher than the upper alarm limit in the ECU. This results in the ECU going into limp mode, characterised by a sudden loss of power. It can be brought on by keeping your foot flat, long hill climbs in top gear, or whilst towing something heavy. A larger exhaust system allows the turbo to spool quicker and generally sit at a slightly higher boost level. In my case, I seemed to have picked up approx 1psi in sustained boost, and 1.5psi in the initial spike before the system regulates (about 1 second).
Some vehicles/exhaust brands seem more prone to it, whilst others have no issues.