Im having a strange problem and I don’t know what it is exactly. I have an Sr with vspl intercooler, BOV, profec BII turbo elbow, downpipe and exhaust etc…This is the scenareo(sp?).
Ill be driving and floor the pedal in second and reach my desired boost set on the profec B. If i do the same in any higher gear, at around 3500 or so rpm the boost will go up to the set boost then once it rises some more rpms (700 or so) it suddenly falls down to .54 bar or so which is stock boost off of the wastegate. What could be the problem? My settings? I figured if it was a vaccum leak or boost leak the car would run and idle like garbage right? Well the car idles and runs prefect untill this happens. With the boost controller off it doesnt have the little studder or anything and just runs off of the wastegate which is to be expected. What could be the problem?
You could have a problem with the wastegate, get an HKS, if so. Also, you may have a boost leak that only shows itself at a certain amount of boost. I had a similar problem and turned out I had a blown turbo gasket.
I also noticed tonite that as the rpms get higher the boost drops lower. Somethin is definately leaking, just gotta find out what. Any suggestions to find out whats leaking?
you can do a pressure test . When I used to drive turbo cars , I made a special coupler that connect to the turbo inlet and with a compressor at moderate psi , pressurize the entire system . You will hear all the leaks and all , most leak will be at the intercooler piping and silicone coupler . May also be the turbo or the intake manifold .
I use to pressurize every week and still managed to find leaks
hope that helps in some way .
so all of second gear will hold your desired boost but any other gear wont?
Are you sure the boost isn’t just spiking then coming down? what is your target boost? a T25 wont hold .8bar or more over like 6500rpm… it will start tapering down naturally.
take off the Profec, and re install the OEM pressure hose to the wastegate…see if you get ANY fall off there, if your just dropping to OEM wastegate lvlv’s then your gate is fine, it’s your profect press sensor or solenoid that screwy…
^^ thats a good idea, have to try that one too…yet i did notice tonite that it falls way further than stock boost also…i saw it fall to about .45 bar and probably would have kept dropping if i kept on it, but it is definately a good suggestion.
Thanks guys for all your help, gonna try and work the problems out saturday and will let you know what i find.
