I have a evo 9 mr has ams fmic, licp, uicp, forged bov, megan header, ams full turbo exhaust wit 4inch dp, injen intake, hallman pro mbc, boost gauge and wideband, my car got hit on the parking lot light damage guy messed my wheel and bent my suspension and a body shop repaired everything before the repairs my car ran 101 gas on 26psi of boost and now my mbc is turned all the way to the + and iam only doing 21 spike and it tapers to like 15psi in 1-2 gear .. but 3rd it hits 21 nd tapers to 18,17.... i thinl that might be okay. But my boost wont turn over 21psi before the accident i was doing 26-27ish. Could boost leak cause this? Any help would be appreciate. Thanks

 

Really dude, punctuaton? I hope English is not your first language... no body can understand what happened exactly.


Boost issue can be from boost leak, improper installation of MBC, or a WG issue.

 

lol No Mr. PEFECT english is my 5th language. I just dont have time to type PERFECTLY. I was just asking if anyone can help me out with my boost. It will not go over 21psi and the MBC is all the way on the positive side. Could it be because of my header? I feel like its leaking air. MEGAN sucks.

 

Lol. Fail again.

 

what is this an English class? All he was asking is, can a boost leak somewhere cause him to lose the boost he had before the accident? Well at least that what i got from it. So in answer to your question i would say yes a boost leak can possibly be the reason your not hitting more boost. Im sure then can be more possibility but im not an expert so ill just give my opinion and hope maybe someone with more knowledge can chime in. Good Luck

 

and also its not a header its an exhaust Manifold sorry its a pet peeve lol

 

So, I am just wondering where you car got hit. Front end or rear? Why don't you do a boost leak test first? Check the header for cracks with a high intensity light looking for cracks at each individual flange/primary weld.

 

It got hit on the driver side on the fender and the wheel. I did a pull today in 3rd it spiked at 21psi and tapered down to 15psi, is this okay? It never tapered down that low.

 

i would definitely do a boost leak test and maybe check your exhaust manifold on my MBC with stock 8 turbo, pump and injectors my boost hits 24.5 and tappers to 22.5-23

 

Yea do a boost leak, something isn't right. Just be careful driving it.

 

...come on, there is a difference between English class and writing a sentence to properly communicate a thought.

You should be able to hear an exhaust leak.

 

Well the exhaust sounds normal. I just installed a race pipe today to the car and still tapers like crazy 21-23 psi spike and goes down to 15. Where the header bolts into the head it looks like there is black smoke behind it looks like its been leting out smoke... I will put my stock header back in.

 

I understand that man but i mean at least if your gonna bash on his grammar, toss and idea out for him too. but anyways again test for leaks everywhere should be your first thing to do.

 

I speak 5 language, its confusing sometimes. People are just rude nowadays. But where the stock boost solenoid hoses plug in is that supposed to be connected the wire that comes from the mass air senor down into the stock bs? Because mine is idk if it was before.

 

As a rule of thumb, there is a 2:1 ratio between exhaust pressure and boost pressure on a turbocharged gasoline engine. So, if your exhaust manifold/header is leaking 10 PSi of exhaust pressure, then you will probably see about a 5 PSI drop in boost pressure.

If you see black, smoke colored stains on the manifold or head then your tubular manifold is probably cracked at a weld or warped at the flange surface. The Megan headers used to be prone to leaks. I don't know if they have improved their quality recently or not.

I think that switching back to the stock cast iron manifold is a good idea if you suspect a manifold leak.