i have nothing but all bolt on mods, Turbo back Megan Racing exh. typeS BOV both springs, standard allen bolt and nut manual boost controller and intake.. my car is boosting over 1.55 bar and way higher sometimes and im getting fuel cuts out the ***. my MBC is mouted on it side could that have anything to do with why my boost is going up so high?? could my MBC be getin stuck? i had to cut the spring to allow the bolt to back off to lower it some, but thats not working... HELP

 

What year is your evo? '05 models and up experience boost spikes which is completely normal.

 

My 05 used to spike to 24 lbs when the controller was set to 21ish...

 

2003 EVO8. should the MBC be up right or can it lay on its side.?? or does it matter, i no it a ball and spring controller..

 

did you add any new mods and did the outside temps drop or increase recently?

 

if anyone have any imfo on this please help, this is really wierd.. a leak would lose boost what the F@@#$ is giving me to much......??

 

I live in Maryland and it just starting to get warm 60-65. i added a voltage stabilzer too.

 

Your MBC might be hooked up backwards...... The symptoms you describe indicate that possibility. Try to swap the hoses going to the MBC.... Be careful there. You could end up with engine damage.... Check out this diagram. It's the correct way to do it.

 

Well, first of all, why do you have such POS MBC? It may or may not be the cause. Secondly, why do you have all those mods without a tune? Of course you're going to hit fuel cut with those mods and no tune. Your car is a walking time bomb with an untuned intake and overboosting MBC.

1) Uh, turn the boost down? Have you even tried that yet? If so, does it not go down at all?

2) If not, then your lines are probably backwards like silverEVO8 said. It's very common.

3) Lying on its side? Dude, no, that's completely irrelevant.

4) If the MBC is hooked up properly, then I suggest going to one of the 1500 members of the DCEVOCLUB and borrowing a REAL MBC to see if switching a good one helps.

5) If that doesn't work, then go to one of the many local Evo vendors in the DC area for some troubleshooting help.

 

Thanks guys for the help dont mean to be such a pain...
1- i will check my hoses...
2- **i want to turn the boost down to 18psi or 19.5psi but it wont go down....!!!****
3- i will mount my MBC upright instead on its side...
4- ill try a new MBC if none of they above works...

 

Then I'm sure it's an improper installation. Just switch the connections, and it should work.

3) I said it's completely irrelevant. That's hilarious to even think it matters, hah. I ran my Hallman MBC sideways while connected to the radiator fan bolt for 6-8 months and went fast as hell at the track.

 

Like everyone said check to make sure you haven't blown a hose off, check to make sure all fittings are tight, make sure that you don't have the MBC installed backwards.

You have a very simple problem that could lead to a very complex rebuild. Don't drive the car (in boost) until you figure out what is wrong.

 

Warrtalon, nrcooled,, i check all my connections and found that the port on the turbo/wastegate-- cap had blow off i guess thats what was causing my over boost!! i still mounted my MBC upright in a better spot.. ill see how it works when i take a ride later.. I went to DCEVOCLUB FORM... nothing beats EvolutionM man, its the best site for EVOs hands down!! Thanks for your help guys,, you all know your stuff!!!..... LATER

 

EvoM is good, but DCEVO is local, so you can get help in person from very knowledgeable guys. Hell, I trained them all, haha! (j/k)

 

Same problem here (RMR turboback, O2 Housing, blitz sus air, walbro 255 and SAFC 2). I use greddy profec b to control boosting and even that i set it to 24psi goes above 26psi. When i was without profec b and SAFC, had again the same problem but at 22psi.


2 things i have concluded.

1. This happens when i go with 3rd or 4th gear and low rpm and step on gas really hard
2. It has to do with the weather.