Losing boost at WOT.

[tbonitz301]

Everytime i go wide open the car will go to 15psi which is what its set at, and then fall back to about 11. If i feather the gas the boost will go back to 15psi for a second. My wastegate is tee'd into the bov line. Im not sure if that could be the problem. Also im running a turbo xs BC.Any thoughts?

 

[eclipsetech]

Talk to RRE
they will stand behind my statment. they do this on all there cars. they tune beter than any shop for our cars, i would listen to them.

 

[appeartobelosin]

He hits 15psi then drops to 11psi which is a spike, not creep. He doesnt start to get more boost he loses boost.

So true. my car would spike at 14psi and then drop back to 11 or 12psi. i found a leak in my MBC and my BOV. when i fixed that it stays at a constant 14psi until i let off the gas

 

[tbonitz301]

How could it be a spike if my boost is set at 15psi. If it was set at 10 and flying up to 15 then that would be a spike wouldnt it. Please correct me if im wrong. Also i no longer have the mbc tee'd into the bov line and it still does it. It steadily rises to 15 and then drops to 11 within a second. If i let up on the gas just a little it will go to 15 then drop to11 again. This is so damn frustrating because its like a 50hp difference and my car feels slow at 11psi. Also im running a brand new big 16g

 

[appeartobelosin]

best way to install your MBC. i was having the same problem you are having until i did this....run a hose from the nipple on the turbo to the inlet on your MBC and then run a hose from the exit side of your MBC to the wastegate. after i did this i can hold a constant 14psi at WOT. try this and let me know how it turns out. if you have an concerns on what im talking about please ask or i can email you pics of my set up. good luck

 

[knochgoon24]

Is there anyway to test my mbc? Can i take it apart and inspect it?Thanks eric

If you have an air compressor, you can set the regulator on it to whatever boost level you want to run. Then, hook a hose from your compressor to your mbc. Then, slowly open the valve on the tank and see if the mbc opens at your desired pressure. Once you find that out, slowly adjust the pressure regulator lower. Your valve should then close before the pressure drops too far.

That will tell you when it opens and closes...though it should be at the same psi.

 

[Raph]

How could it be a spike if my boost is set at 15psi. If it was set at 10 and flying up to 15 then that would be a spike wouldnt it. Please correct me if im wrong. Also i no longer have the mbc tee'd into the bov line and it still does it. It steadily rises to 15 and then drops to 11 within a second. If i let up on the gas just a little it will go to 15 then drop to11 again. This is so damn frustrating because its like a 50hp difference and my car feels slow at 11psi. Also im running a brand new big 16g

And your factory EBC valve? its not still in there?is it?

And you have done your boost leak test?

And you havent ghetto rigged your stock hoses to fit the j pipe?

And you did use hairspray on all couplers to eliminate any chance of leaks at the initial assembly?

 

[tbonitz301]

Yes bcs hoses have been capped off although the controller is still plugged in.All intercooler piping is professional.no ghetto rigging. no boost leaks.Its a bleeder style mbc which is cheap but bulletproof in my opinion. So what do ya think?just thought id add that it took 60+seconds to bleed down 25psi