I had a boost leak on my Megan Header had a few cracks, which i replaced today with the stock one. I took the car out and did a pull in 3rd gear... The car spooled slow, it hit 23psi and by 7,000 rpm it droped to 16psi. The Hallman MBC was on + all the way. My car is also on e85. This doesnt feel right, I know the car has no other boost leaks, I checked everything and did a boost leak test. What can be wrong here? Maybe the wastegate? Someone who knows this stuff please help me out here. Negative comments keep to your self please.

 

consider a retune...

 

I am trying to get the car retuned. Thats why Iam trying to fix this, I installed injectors and pump and made the rom to run e85. But i just went out and switched the MBC hoses around which should make the boost go insane spike 30+ but it didnt it spiked 23psi and let down to 15. Any ideas?

 

You have a cat? Could be collapsing.

This is why mod lists are important in help threads

 

Car has ams fmic, licp, uicp, forged bov, stock header, ams full turbo exhaust wit 4inch dp, injen intake, hallman pro mbc, boost gauge and aem wideband, 1000cc IDs and walboro pump runs on e85. Also i took of my Hallman MBC and just left the hoses in the engine bay and I took the car on a pull, the car still did 23psi and tapers to 15psi even with out a MBC how is this possible?? wouldnt it shoot straight to like 30+

 

Some one knows please help, this is a serious matter. :[

 

Anyone know what could be wrong?

 

Anyone??

 

Sometimes negative comments can be helpful.

 

This may be a negative question, but I am going to ask it anyway.....Don't the Hallman MBC's have different rate internal springs available? I am wondering if the OP's Hallman might have one of the softer springs installed?

 

Headers can't have boost leaks. Headers can develop exhaust leaks.

Seriously though, I would be willing to try and help you out. Check out a current thread over on the, Turbo/ Engine/Drivetrain sub forum, entitled, " Only 28 PSI??". There I will describe how to go about checking wastegate spring pressure and how to adjust preload on your adjustable waste gate actuator.

Although, he is controlling boost via the ECU and you are employing a MBC. The basic procedure is the same. You are going to want to remove the MBC from the loop for purposes of verifying WG spring pressure and setting proper preload level.

To remove the MBC from the loop just disconnect two hose ends from the MBC hoses at the point where they connect 1) to the nipple on the WGA, and 2) to the nipple on the J-Pipe. Plug the open hose ends with golf tees. Now get a couple feet of 4mm hose from the auto parts store and connect it from the WGA nipple to the J-Pipe nipple.

Setup in this fashion do a WOT run in 3rd or 4th gear. Report the boost reading indicated on your boost gauge.

 

my header was cracked, so i installed stock one and the bolt broke that tightens the header to the turbo, now i have to take the bolt out and put new one in. this will suck....

 

That does suck. If it is any consolation, it happens to everyone