How to read boost pressure levels.
 

hello,


I am turboed with works turbo kit. I got a 8 psi wastegate actuator but my tuner has said it makes 9psi from the wategate pressure. How could that be? Base on my datalogs.

https://datazap.me/u/bboyairrick/boost-0?log=0&data=21

I determine boost from Manifold Absolute Pressure. WOT 3rd gear @ 5800rpm shows Manifold Absolute Pressure at 1.52 Bar. Atmosphere pressure is 1 bar so its .52 Bar which is around 7.4 psi. Am i wrong here?

Only thing i think my tuner is talking about is Boost Target which shows 1.6 Bar = .6 Bar = 8.7 psi-ish.


I took off my internal wastegate actuator and checked with an air compressor regulator to see when it actually opens at. It seems to crack open around 5-6 psi and fully open at 7+psi.

any help or suggestions would be appreciated

Your wastegate is the lowest pressure you can have with it open.
Boost creep is a thing, I would expect a little variance; ask where your tuner referenced the boost from; they probably aren't wrong. Not a big deal

1 psi of boost creep isn’t a very big deal especially at 9psi and especially if your tuner tuned for it.

Boost creep is typically caused by either
A. Wastegate just isn’t physically big enough to “bleed” off the excess air
B. The piping going into wastegate isn’t setup optimally and air just blows by instead of going into wastegate.