I'm having a problem where boost won't stop rising. i can hear the wastegate (open atmosphere) wasting like crazy but boost still rises. this is at half throttle. haven't went full throttle yet. with the old turbo i never had this issue. after i got the slight exhaust leak at the gate it raised the pressure about 1psi for both high and low. now with the new turbo it won't stay down.

 

bigger gate?

 

What 'gate is it and what turbo did you have before the 78?

 

its a turbonetics 38 and it was a t4/t04r. 66.5mm close in specs to the t67 IIRC. old turbo had .81 A/R turbine housing. new one has a .96 and a bigger turbine wheel.

 

Sounds like a waste gate placement problem combined with too small of a gate. Where is your gate placed? You getting both banks flowing well into the gate right before the turbine housing? It will be tuff to keep the 78 in check with a 38mm gate, unless placement is really good.

 

its the trick kit. the gate is in the crossover tube. should i just go to like a 50mm?

 

You can try but the gate placement is about as bad as it gets. The only reason it probably held before was the extreme back pressure. Now you have a decent turbine housing and wheel size so it will probably be no dice on holding a decent boost level.

 

what about everybody else that runs this same setup? just trying to figure out why my doesn't work but theres does. is it because i have mine open to atmosphere?

 

Heavy vehicle and awd is one part, I am willing to bet any one with the same exact setup as you has boost control problems. I would start with a bigger gate but I doubt it will hold a rock solid low boost level. Also venting it to atmosphere will not hurt it one bit, in fact if the exhaust is restrictive it will help you hold a lower boost level.

 

i do have a sts controller. maybe i should disconnect it.