Installed Apexi DP and Cat-Back.. Now Boost is to High

[ChrisGo]

Well after I installed the Apexi downpipe and WS2 catback i took the GSX for a ride. Left the driveway and got into it and BAM!!! I hit fuel cut off. So i go home and install a MBC trying to lower my boost ,and for some reason i can't lower it. Is there something wrong?

P.S. Its a OBX boost controller and i have it hooked up to the compressor housing and waste gate.


Thanks in Adavnce

 

[kenamond]

Profile shows all stock. Make sure it's up do date (if nothing else, add in the exhaust and boost controller mods).

Have you tested the WGA to insure that it's functioning properly? A pressure tester connected to the WGA nipple should cause the actuator to open at about 9psi. Make sure the WG assembly is working (pressure causes WGA to extend the actuator arm and rotate the lever on the turbine housing). Make sure the actuator arm is not interfering with the heat shields.

You can connect a vaccuum line straight from the compressor housing nipple to the WGA nipple. This should give you around 9psi boost and will eliminate the boost controller as the source of the problem (it's possible to hook up the BCS or MBC incorrectly, but it's hard to get a single vaccuum line wrong!). Make sure the vaccuum line you use is in good shape (isn't torn/worn/leaking).

I'd strongly recommend getting an aftermarket boost gauge, since you've now got an aftermarket boost controller in the mix.

Check that stuff out and post back what you find.

 

[ChrisGo]

I do have a Autometer boost gauge. i don't know what i was boosting when i hit fuel cut off, but i know i am boosting over 15psi after that i get scared i do not want to blow up my car ya know....

P.S. i updated my profile, i just installed all those parts today.

 

[blcknspo0ln]

As a rare event, it sounds as if you are boost creeping. You can verify this by going WOT in 2nd or 3rd gear and watching where the boost levels off at after the spike. I.E., it spikes at 13 psi, but settles at 12 psi after going WOT, but then slowly increases boost until 17 psi and you hit fuel cut, that is called boost creep.

Boost creep is solved by porting your turbine housing, among other things.

http://www.dsmtuners.com/forums/search.php?searchid=3490627

 

[ChrisGo]

Well today i played with it a little more and am now able to get it down to a steady 13psi. Is this safe with the mods i have listed in my profile, if not what can i do to make it safe?

 

[blcknspo0ln]

Glad you figured it out. If you have no fuel mods or tuning mods, I would not run more than 13 psi on your setup. If you'd like to run more boost, you can look into getting a larger flowing fuel pump (walbro 190's or 255's are the most common) or injectors. However, getting those two items will require you to get an adjustable fuel pressure regulator and tuning device.

 

[timot]

sell you gto and put the money into your dsm to make 400hp and get better gas millage...jk

 

[kenamond]

Well today i played with it a little more and am now able to get it down to a steady 13psi. Is this safe with the mods i have listed in my profile, if not what can i do to make it safe?

If you get a logger, you can monitor timing and O2v and figure out how much boost you can safely run. With stock fuel pump, no rewire, no logger, I agree with staying at stock boost levels. I run 15psi with rewired stock FP, but I still lean out past 6k rpm. So I let off the gas up top to drop boost or shift before 6k. But I know that because I have a logger.

 

[DGajre777]

Well today i played with it a little more and am now able to get it down to a steady 13psi. Is this safe with the mods i have listed in my profile, if not what can i do to make it safe?

I have run 15 psi on the stock turbo, but I turned it down to 13. I have no fuel mods.

 

[oplix]

i run a Evo3 on stock fuel and anything over 14psi, it leans out after about 6k rpms. Anything over 16psi and i hit fuel cut at WOT.

 

[fwdmaster]

Boost creep my son

 

[kenamond]

This thread is a year old.