i have the stock twins still sequential (99spec if it matters) and when i boost in the primary turbo only, once it has gotten to its 12 -13 psi peak the boost then goes down 1psi then up then down then up. once it hit 4500 and the transition happens, then it goes away. it has this wawawawawawawa sound to it and it is slightly noticeable in the pull of the car. i just want to pinpoint the problem before i start replacing **** that isnt bad. please dont tell me to search. only post if you have something constructive to say. it does this everytme i boost the car.

then sometimes pretty rare, and very random, the secondary turbo doesnt come online or is delayed. like i said, that doesnt happen very much. ideas?

thanks for any help you guys can offer.

-masin

 

mods?

What boost are you trying to run? What controller?

Dave

 

its using stock boost controll with a power fc, dp, mp, cat-back, and intake. it wasnt doing this on the dyno whenit was tuned. about one week later it started.

 

Still using stock solenoids? If so, they aren't capable of sustaining boost over stock level for very long.

 

my roomates fd uses stock ones and his doesnt have this problem. would replacing them fix it?

 

I don't agree with that completely.

The wg and precontrol solenoids are not to be used with elevated boost IMO, but only because they aren't fast enough. The turbo control pressure solenoid can stick when subjected to 13-15psi, but installing a pressure regulator on that line will solve that too.

To the OP, install a proper boost controller. Your setup has very little restriction and the PFC using stock solenoids is not very good at controlling it. A manual boost controller or electronic boost controller will probably take care of most of it.

The situations where you don't get boost are probably more related to the solenoids sticking or a leaky check valve. I would put the controller on first and see where that leads you.

Dave

 

will do, thanks