Boost drop in higher gears?

[alundra]

Ok, I need some advice.

My mods:

Large air filter, piping in 2"5, intercooled, blow-off, cold spark, polished head, new valve guides+headgasket changed 8 months ago, healthy T2, full exhaust line 2"5, standard ECU management in 8 spark head model...

I fitted a MBC, i set up at 12 psi in 2nd gear at same rev in 3rd it dropped at 10, in 4th went to 8, sometimes 6 (not on cheap boost gauge, it's a TIM).

I rechecked all lines (air/oil/water) for leaks, only in steering rack...

What can be checked more?

Who went from MBC to EBC? Does a EVC can hold the same boost in all gears?

Thanks.

[JackieFan]

The only thing can think of that changes on the car between gears is windspeed out side (because with each gear you are traveling that much faster). Are you measuring boost before or after the intercooler?

Maybe it's cooling the air quicker than the little T2 can fill the intercooler

Either way loose the T2 and get either a T25 or T28 on there

[alundra]

Thanks! I'll check the boost before intercooler.

In case of a MBC, must i set in 3rd gear the desired 12psi, despite of spike in 2nd gear?

[wacomuk]

the best way to check your boost is in 4th gear. If its dropping off i would say your actuator is probally week.

[umpkin]

or you have a boost leak, before i got my intercooler setup, i had a small leak in the orange gasket thingy, that did the same, 1st and 2nd wasnt really noticable as you go through them to quick, but 3rd and 4th was very noticable as thats when you stay in it for a longer time.

i would check yer pipes and anything else between the turbo and the inlet.

[alundra]

The orange thing was replace by this: when i fitted my intercooler set up, i knew it was prone to break.

Tomorrow i'll set the desire boost in 4th gear, will know if in 2nd the boost is stable.

P.S: i checked the timing it's at 15°, warm condition.

Are you agree that in same rpm, i'll get the same amount of boost +/- 1psi?