Like the title says for some weird reason I'm getting more boost in the lower gears than the higher ones. I have the ams gt35r kit which uses a 38mm external wastegate and I have it VTA. so how is this happening??? I always though boost creep came in the higher gears because of the increase in load. Ya think its just because my boost controller is a MBC which uses a spring and wont be exactly on target every time I boost???

 

Contact AMS, as they are the best qualified to give you a helpful answer. What boost level are you seeing in lower gears and what boost are you peaking to in top gear? What sort of BOV do you have?

 

ebc's that can increase duty as the load rises work well.

cb

 

I'm seeing like around 21.5 peak in 1st and in 3rd or 4th I see around 18 peak. and its the tial bov that ams sells

 

Boost leak? You are in higher gears longer and you have more time to bleed off boost due to a leak...

 

this is possible. I might try and do a leak down test to make sure

 

Are you sure you're not just getting confused with the taper effect? Whenever you're testing boost, are you baging straight 1st-5th? Or are you measuring in each gear independently? If you're going straight through 5th, then chances are you aren't going to see peak boost because you're already past peak torque in the rev range. It makes sense, but I'm not sure that this is your particular issue.

 

Datalogging each gear independently and logging boost is the only sure way to tell.

 

I agree. I'll probably data log 1st through 4th independently. and no I'm not sure its not just the taper effect. I don't have it tuned to taper down to a certain psi by redline or anything. does boost taper sometimes even if you dont have it tuned to do that???