View Full Version : Boost issue, possibly bad n75?

07-31-2007, 03:54 PM
i have a dahlback 1 bar chip and my car used to boost 15 psi and then drop to about 10 at redline with the ocasional spike to 20-21 psi but recently the car doesnt idle very well, especially with the ac on (this might just be because of the lwfw?) but the boost issue is that sometimes it will boost to 11-12psi and then slowly rise a 1-3psi as i go up the rpm range and then drop down like normal as it approaches redline but sometimes it will boost normal to 15 psi and then drop down as it approaches redline. I am abot to go do a presure test, but i have a feeling that it isnt a boost leak . you guyst think it could be a bad n75 causing these boost issues? thanks alot guys

heres a video of what i'm tallking about

07-31-2007, 07:03 PM

07-31-2007, 07:33 PM
Do the pressure test first. You will be surprised when you find out you had a small leak or maybe even a large one..

07-31-2007, 07:54 PM
probably a small boost leak..if the pressure test proves no leak then i'd say find someone in your area and try their n75 out...could be your diverter valve not staying closed...

07-31-2007, 11:13 PM
well i did a pressure test today and the air pump i was using was not powerful enough to put alot of pressure into the system, i think my boost gauge showed 3 psi but it was enough to find a huge leek that was in the vaccume line that goes accross the engine bay on the firewall, the heatshield i had made was rubing on it and caused a hole in it. Well i patched that leak up and ran the car and it boosts higher and idles alot better but the boost still fluctuates alot when i am at WOT ( the boost keeps going up and down from 10-15psi so i am thinking that i may have another boost leak but i need to wait till tomorow and go get a stronger pump. you guys think the boost fluctuating could be because of another boost leak? also my boost gauge sits on -4(or 4 vacuum) when the car is off so that means that whatever i boost it is really actually 4 psi more than what the gauge shows right? Is there anyone in the sacramento area that is willing to let me use their gauge to see what i am actually boosting? thanks alot guys.

hers a quick video i took