Wastegate creep?

[ADV_93]

I hear and see this alot and still don't know what it is, i'm sure one of the knowledge folk could help me out!

[ste91]

Usually happens when the actuator spring becomes too weak to hold the wastegate shut, and it starts to open before the set amount of boost.

This means it takes longer to get on full boost because instead of all the exhaust gas going through the turbine, some of it is escaping out the wastegate instead.


The other problem that often gets mixed up with wastegate creep is boost creep.

Boost creep happens when the wastegate hole is literally too small to let enough gas out, the only other way it can go is through the turbine, which creates more boost.

[ADV_93]

Usually happens when the actuator spring becomes too weak to hold the wastegate shut, and it starts to open before the set amount of boost.

This means it takes longer to get on full boost because instead of all the exhaust gas going through the turbine, some of it is escaping out the wastegate instead.


The other problem that often gets mixed up with wastegate creep is boost creep.

Boost creep happens when the wastegate hole is literally too small to let enough gas out, the only other way it can go is through the turbine, which creates more boost.

Cheers for that pal! So, of the 2, you want boost creep! Hahaha

[ste91]

Haha you don't want any!


To cure boost creep, you can either weld up the standard internal wastegate, and fit a larger external one, or you can port/enlarge the standard one, but you may have to fit a larger wastegate flap if you go too big.

To stop wastegate creep, fit a new actuator spring.
But it's also said that fitting a boost controller can help in some cases, as it's fairly common for wastegates to start opening slightly before their set pressure i.e. if boost is set to 20psi it may start to crack open at 18psi, but if you have a boost controller set to 20psi the actuator doesn't see any boost at all until the boost controller gets 20psi.