MSBC surging

[Aeroking]

I'm running a multi-stage manual boost controller with my external wastegate, and i'm having a really tough time getting the thing to cooperate. my target being 15psi in the 1st stage, and 23-24psi in the 2nd stage

the controller is 2 manual bleeder valves, connected by a solenoid switch. with a course boost adjustment ball/spring.

when i plumb the system using only the bottom WG port, the turbo surges to 26~27psi in overdrive, no matter what spring i have in the wastegate. The controller works for a second, then the turbo just pushes through, and overboosts.

When i plumb it so that both wastegate ports are in the system, all i get is the spring rated boost, in both stages.

 

[1madgumby]

Re: MSBC surging

I'm running a multi-stage manual boost controller with my external wastegate, and i'm having a really tough time getting the thing to cooperate. my target being 15psi in the 1st stage, and 23-24psi in the 2nd stage

the controller is 2 manual bleeder valves, connected by a solenoid switch. with a course boost adjustment ball/spring.

when i plumb the system using only the bottom WG port, the turbo surges to 26~27psi in overdrive, no matter what spring i have in the wastegate. The controller works for a second, then the turbo just pushes through, and overboosts.

When i plumb it so that both wastegate ports are in the system, all i get is the spring rated boost, in both stages.

Do not run the truck hard in OD it will burn out the OD bands in the trans. been there done that. prob. why it is over boosting. the trans is slipping realy bad. might be to late & the od in the trans. is shot.

 

[Aeroking]

Re: MSBC surging

hmm. so the trans slipping would cause the engine to free rev and surge the boost? trans never breaks 120deg, so i dont imagine it would be burning up.

i'll try leaving it in 3rd, and see if they boost keeps stable. it just runs to 100mph so quickly, its tough to remember to let out before OD. but i'll try it.

also, perhaps its the size of the wastegate. its a F38 Tial, trying to regulate a 72mm at 20+psi. i dont know if i need to step up the WG or not.

 

[Aeroking]

Re: MSBC surging

just took the truck out again, still surging as soon as it gets to 18psi. and just as strange, the both stages of the controller surge to the same pressure.

so i'm clueless at this point. i want to have 2 boost stages, but this controller BS is getting old.

would it be beneficial to run the boost controller feed from a port on the intake, instead of the port on the compressor housing?

 

[Aeroking]

Re: MSBC surging

i put on a boostvalve (ball/spring) i had in the drawer, and it held perfect at 22psi, jumped 1/2psi in OD, but thats normal for the truck.

:rant: anyone wanna buy a fancy manual boost controller?