Boost issue

[JDM EJ1 95]

anyone ever have this problem before


my car will spike to 22 and then hold at like 19-20

but before redline itll start creepin up to 25psi and it just keeps goin.


i put an MBC on it last night and only ran 14psi but it held it fine.


now.. do you think an N75 valve is the culprit.

my car has a MINOR MINOR.. idle fluxuation.. and when i put the MBC on it went away.

so i am thinking my N75 may be bad?

[S4evr]

did you run only mbc last night, or parallel to the n75?

[JDM EJ1 95]

mbc only

[BurnAll4S4]

my car would spike to 25 and taper to 23 on my n75, but that was with my old shitty VAST tune. i took out the n75 and ran standalone MBC on that same tune and it ran great. My MBC tapers a bit, but i know thats the MBC, need a better one.

to answer your question, your n75 is the culprit. wether its the tune or the MBC. you can figure out which one by logging it.

[JDM EJ1 95]

i dont have the capability to log anything.


and its not spiking to 25...

after the spike and the taper it jumps to 25 and holds before redline.

[BurnAll4S4]

i understand that, just saying my situation.

i believe its channel 115 on a vagcom, you dont have the cable and a laptop? if not post up in the regional section im sure someone will be happy to help you.

[JDM EJ1 95]

yea ill see what i can come up with. and post back

[The_Jerbel]

That's called boost creep. It happens mostly in the higher gears. The N75 is likely faulty, either that or the tune requests too much boost in the higher rpms.