First let me say that I did search and all I got was people having problems with their sequential system and I am full non sequential. The problem is when I wot and shift gears at high rpms, the boost will drop dramatically. 12 psi in 2nd at 6700 rpm, shift to third, drops to 5-6 psi. I tested the samething between 3rd and 4th and got the same results. I do also notice a slight psi drop at high rpms of about 1-2 psi from when i first get on the gas. Anyone have any ideas? Again let me say that I am full non seq with a ported wastegate, fulll exhaust, fmic, ecu, intake. Any input would be appreciated.

 

Pressure drop at high rpms usually means that your turbos have reached max output. You either have a boost leak somewhere, your wastegate is leaking a little, or your turbos can't put out anymore air than that.

As for the pressure drop between gears, that's going to happen, especially if you shift slow. Your BOV is going to release the pressure, and then it'll take a moment for your turbos to build boost back up.

 

Full nonsequential means you have basically a wastegate, BOV, and that's it. So your troubleshooting list is:
- boost leaks
- wastegate/wastegate actuator/boost controller
- blowoff valve
- exhaust restriction (bad cat?)

Dave

 

is the proper set up for a non seq mbc this?

ypipe nipple - hose - valve to regulate air - hose - inlet (top) actuator nipple, outlet (lower) actuator nipple - hose - bleed valve (ball and spring for example to bleed pressure.) I read a old post and this is how they describe a mbc system. If this is the way to go, how much should the regulation valve be opened opposed to the bleed valve?

right now all i have is the relgulator valve for the air between the ypipe and inlet actuator nipples and the outlet of the actuator capped off.

 

could a dp intended for rhd rx7, the ones bent to clear the steering rack at the top, be causing my boost problems?