Gman, im having a weird boost problem! Was making around 13-15psi, and now for some reason im getting 5psi, but once in awhile i will hear my exhaust sounds deeper (bit louder) then it will boost to about 10psi, doesnt want to give me anymore and this only happens sometimes. Cant seem to find the problem, really starting to **** me off, really need some help. Im running microtech Lt10s, s5 13bt monsta port, s5 throttle + inlet, all polution gear removed + plugged, s5 hiflow turbo 30mm internal gate, 1.5" screemer into main, 3" mendral stainless, 3" TurboGeni hiflow cat+muf, s5 ic front mounted, 2" mendral pipping, TurboSmart dual stage boost control. Please help!

 

Remove the boost controller and see if the problem remains.

 

I have had similar issues in the past caused by boost leaks. Could be something as simple as a loose clamp or a torn coupler. I would go through the system and look for leaks, pressure test if you can.

 

Have removed boost control and ran turbo with wastegate vacum line disconected, no difference. This should give me full boost right? Also tested wastegate and boost controler with 15psi compressed air through the line and all works good. When controler is boosted above 15psi, eg.20psi, wastegate dosnt open, when below 15psi, eg.10psi, wastegate opens smoothly, air off wastegate snaps close. Noticed that when i opened wastegate on idle, exhuste sound got deeper, same note i here when it gives me 10psi. Any suggestions?? Thanks for ur reply

 

Hi mate, already checked all my lines and gave clamps an extra notch up, all clamps tight. There dosnt seem to be any torn cylicon links. Any suggestions as to how i can presure test the system. Thanks for ur reply.

 

BOV sticking open?

It's going to be an issue with the wastegate or turbo. Since it's intermittant, then one can only assume it's a wastegate or BOV problem. If it was the turbo, then boost would be low all the time.

 

Yes, this makes sense. Im running a stock Rx7 s5 BOV, its old and maybe worn. Any suggestions to how i can test BOV? And is there any trix to get BOV working again? Thanks again!!! ;-)

 

You can test the stock BOV with a vacuum hand pump. With vacuum applied, you should be able to blow air through it. With zero or positive pressure, it should be closed completely.

 

Thanks everyone for ur replies, i have found the problem thanks to all ur input. It was the old s5 BOV, switched it and brat brat she rips. Thanks again. ;-)