So I installed my TurboSmart MBC the other day, all seemed well with out 3rd/4th gear pulls. Because of where we mounted it I was not able to put the cold air arm thing back on. So today I floored it in 2nd and the powerband felt really bouncy, like power, no power, power, etc etc. Its not as if the car hits a wall, then jets off, or anything near that bad, but you can just feel that it is not as smooth as stock. However the problem only seems noticeable in 2nd.

The MBC is at 21 psi.

Whats wrong?

 

It could me many things. Clutch could be slipping. A boost leak. Fuel cut. I'd boost leak test it first.

 

It felt fine before the MBC though. Im pretty sure it has an aftermarket clutch too.

The laggier feeling parts of the powerband aren't violent by any means, nothing like boost cut. You can just barely feel that it isn't making the power that it is at other points.

 

what gas are you using? and there is the wastegate flutter that all the evos have, but that's not noticible enough
oh, and we like to call that the "snorkle" here, but I don't think it would affect the driving like that

 

91-93 octane.

I used all new vac lines during the install, if that makes a difference.

Could it be the boost controller? I know everyone uses Hallman, mine is a Turbosmart.

 

If you're on 91, it could just be the car pulling timing with 21 pounds of boost. Mine was doing it pretty bad, try lowering the boost to 19 and see if it still feels like "power on, power off, power on"

 

Ok, it is rather hot lately (90's), and maybe coupled without the snorkel its causing detonation?