Finally i get my ECU back after being flashed drive it up to the car shop to get my MBC installed ..car feels great..so smooth...they install the MBC and set the PSI...starting from a stop the PSI holds great..but going from a roll the PSI shoots up to about 25-26 PSI...turns out to be my POS bov(plastic 1)cant handle...but thank god i get my JDM EVO DM on monday..install that and we should be good...

 

That has nothing to do with the BOV. Please give me all the details right now so we can figure it out. The same problems will occur with the MR DV, so we need to figure out what is wrong.

Which MBC?

If it's the Forge, which spring? Did the shop mess with it? Where did you get it? Which spring is being used?

Did they use new vaccuum lines? Did they tap the BOV line or use the compressor nipple?

When you say from a stop the PSI holds great, but from a roll the PSI shoots up? What's the difference? From a stop, you start rolling just like if from a roll.

Did you hit 25-26psi in higher gear, or in 1st gear? Are you saying that your psi was lower in 1st, but then in higher gears, you saw 25-26psi?

Answer all of these.

 

+1 to Warrtalon.

I would put some race gas while you figure this out, just to keep away from blowing things up with overboost. Friendly thought

 

nah i have the turbosmart and i got it from them..i know ppl are gonna say its bad but they have 800whp civics and other cars with that MBC and have no problems...im sure they used new lines..they said if they started from a stop and just went through all the gears at red line it was hit 21-22psi like it was spose to...but from a 40 mph roll in like 3rd hgear and floored it it would hit like 25-26 PSI...they went on Evom to see the proper way to install..so i dunno i go in monday and ill let u guys kno...and when they installed it they came on here and made sure they did it right..so im 99.99% sure its installed right...they guys are really really good and know what there doing so i dont kno whats goin on?

 

Bottom line:

More than 21psi on pump gas will cause engine damage, period. Show me an 800HP civic on pump gas.

Crank the boost down.

 

but ihave a tune and everything....im not just cranking the boost up on a stock EVO...talked to wartalon and he said it was fine to spike at 21-22 PSI..

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hks hi-power exhaust, JIC downpipe, helix high flow cat pipe, walbro 255 fuel pump, JDM EVO MR DV, turbosmart MBC, and a dynoflash

 

Anything more than 21 psi will blow the motor D*mn. Are you talken about a 21 psi spike, or 21 at WOT

 

Look, man, you're not spiking to 21-22psi. You're spiking to 25-26psi. Of course it only shows 21-22psi when rapping through the gears, because you're never below 5500rpm. We hit peak boost/peak torque down around 3700rpm, and then the boost tapers down. So, this means you are running WAY too much boost. Here are some fatal mistakes you are making:

1) Thinking that just because a shop uses a part on a 800whp civic that means it's good for an Evo. Terrible, TERRIBLE MISTAKE!

2) Assuming that because a shop knows how to install this MBC on other cars that they also know exactly how to do it on an Evo. I'm sorry, but the Evo has a complicated system due to the restrictor pills, and there's no reason you should be spiking to 25-26psi with the boost turned down.

3) Thinking that 21-22psi up at 6k rpm is ok just because you're shifting through the gears quickly. Always set your boost based on the initial boost spike from a slow roll at low rpm.

 

Wait. You took it to a "tuner shop" that had to go on-line to learn how to do the mod? This means to me it was their first attempt at an Evo. Then they did a test drive and noticed a problem, but didn't fix it... and blamed the BOV? For crying out loud. The problem with the plastic BOV is that it leaks boost. It doesn't keep more in there!

You've got yourself a problem and you better take care of it ASAP or risk tweaking your engine. Try taking it to a real tuner shop that knows what they're doing.

 

Clayton, you should not only correct him, but you need to correct the rest. The statement that "Anything over 21psi will blow your motor" and "more than 21psi on pump with cause engine damage" is pure BS. It is more complicated than a simple equation.

 

That's true. If there's knock or too much boost, the stock ECU will pull timing to protect the engine.

 

Or try its best to protect the engine. It doesnt always succeed.

 

no its the shops fiorst attempt..these guys are well known..and have done many works on an evo....the shoped as 2 500whp evos....i went and drove my car today....from a dead stop from 1st gear all the way through its spikes at 21-22 PSI...but when i do it from a roll, it spikes all the way to 25-26 PSI...so i dont kno what is up

 

make sure you are using the compressor nipple as the souce and NOT the BOV method...

 

Obviously the shop doesn't know what they are doing if...
1) they had to go on an evolution forum to figure out how to install a boost controller and
2) they blamed an overboost condition on a leaky BOV

You need to stop driving this car and take it either back to the original shop to have it fixed, or even better take it to a different shop that knows what they are doing.