t25 boosting 22 psi???!!!!!!!!! help please

[rental4free]

i'll start off with my car 2G <with stock turbo> I'm tapping my boost gauge to my fuel pressure silonoid (how ever you spell that word) and it reads 22psi when i'm gunning it but only 15 when it's about 1" off the floor. For some reason i can't adjust my MBC it's not working i guess. do i need to try a different line? the "P" line on my TB is plugged so don't suggest i do that cause i can't. the previous owner screwed with the EGR system.

 

[blackGSX2g]

Keep it tapped into the FPR line.

Are you sure you hooked up your boost controller right? If your wastegate isn't getting any pressure, it will never open and you will boost as high as it wants. Make sure you've got the hoses going the right way into and exiting the boost controller.

 

[TotalEclipse112]

Yeah sounds like no pressure to the waste gate actuator. Get a good vacum diagram and try to tap someting before the throttle body which is ported vacum. If you go from someting after the throttle body that is manifold vacum and dosent work as well.

 

[blackGSX2g]

Yeah sounds like no pressure to the waste gate actuator. Get a good vacum diagram and try to tap someting before the throttle body which is ported vacum. If you go from someting after the throttle body that is manifold vacum and dosent work as well.

Most boost controller manufacturers recommend to use a pressure source at the manifold for 15psi or more. That is where the pressure changes first.

If using manifold vacuum doesn't work well, then why is the BOV routed from there?

 

[KeltonDSMer]

Total, just think about it for a second. Having the WG source before the TB is simply a bad idea. When you are at part throttle, the pressure in the pipes is much higher then that of the intake mani. If your boost gauge is reading 5psi, then the pressure in the pipes is likely over 10psi because of how big the pressure drop is across the TB. If your WG source is from before the TB, it will open pre-maturely and not allow you to make good boost during part-throttle situations. Just my $.02.

 

[TotalEclipse112]

You can do either, but in my past experinces I have used ported rather than mainfold. It usually worked better for me, maybe I just had my vacum lines screwed up. I did build my last couple of DSM's before I went to school for automotive, so I just made things work rather than just figuring out why they didn't work. So yes the is a chance that I could be wrong on this one.

 

[gsxeclipse97]

From my experince the bov was not the best place to run the boost controller, I used the nipple that comes off of the t25 and went from there. Now i can adjust the boot level alittle better but the t25 spools so quickly that it spikes unless i turn it all the way down and then it still runs 12psi. right now it running 16ish but it will spike at 20 and then slowly drop down to 16 depending on what gear and all of that sort.