jonslam

Hey guys, I am having troubles with overboosting.
I have a turbo d16, stock internals with a t3 Air Research turbo, I have an internal wastegate with a 8 pound spring but am hitting more than 12psi... I don't hit boost anymore because I saw it hit 12-15 psi more than once.

I checked the wastegate, it moves. the actuator arm also moves but is difficult.

I recently cut out my resonator and also put in a test pipe, could that cause the overboost?

Im hanging on a thread here i don't know what else to try.

Im new to this forum so take it easy on me haha any help would be amazing!
Thanks

92cxyd

test pipe change would not effect this issue.

Has this been happening since day one or started recently?

Check you signal line to the wastgate, make sure it is not pinched or cracked or disconnected.

wantboost

iTrader: (2)

has the weather changed a lot where you are?

if it's done this from day one then the internal wastegate hole is too small and the actuator can't open the flapper enough.

the best option is to enlarge the hole so it flows more, this might require a larger flapper but normally you can open them up a good bit with the existing flapper.

what are you using to set boost pressure, just what the wastegate is set at or some controller?

wantboost

iTrader: (2)

depending on exhaust diameter and how restrictive the cat was the test pipe can definitely cause an increase in boost pressure as you've reduced backpressure in the exhaust system and increased flow, this means the turbo not only spools slightly faster but the increase in flow means it takes more flow through the wastegate to keep boost levels in check.

jonslam

It just started recently, its straight through my muffler is cut off to so idk ... Would that cause it?

Zaridar

8 pound spring shouldn't be hitting 12 psi due to decreased back pressure.. Are u positive it's 8 # spring or is that just the boost you normally hit off the spring before exhaust was modded. Check for vac leak in WG vac line as this would ack like a manual boost controller increasing boost pressure

jonslam

I checked vac lines, all seemed to be intact. although when I pull of the the actuator arm, I can extend it a fair amount, when I put it back onto the clip of the wastegate and then pull it, I can maybe pull it 2 cm before it stops, could this maybe mean the preload on the actuator arm got messed up and is at the max that it can extend prevent the wastegate from opening?

wantboost

iTrader: (2)

check flapper arm travel with the actuator unhooked, normally with internal wastegates the actuator has more travel than the flapper does, it will hit turbine housing or the turbine outlet elbow/flange before the actuator hits its travel limit

what size t3 is it? how is the turbine outlet designed, does it have a separate flapper on an elbow or is it like a 3 bolt outlet with the flapper in the housing?