I recently changed to a water to air set up, and have run into some problems. the only thing that was changed was the intercooler set up. Now the car is overboosting even with regulating boost with the wastegate spring. intercooler core is mounted where the battery used to be (97 prelude) the charge pipes are a pretty short run to the core and from the core to the intake. hitting boost cut at 6.5 lbs, i can hear the wastegate opening and also took the wastegate apart to verify that the tial wasnt broken.

here is the set up,
garrett t3/ t04e stage 3 turbo (.60/ .63)
tial 38mm wastegate, 5 psi spring, custom dumptube.
12x12x4.5 water to air intercooler core
2" charge pipe hot side
3" charge pipes cold side

running the wastegate signal directly off the compressor housing to the bottom of the wastegate. with the pervious front mount setup i never had this problem. I have a few ideas but all suggestions will help out.

 

are you sure it is boost cut, or are your IATs significantly different now and the tune up doesnt know what to do with them? or am i in left field? i am not feeling too good today.

 

maybe u are getting some creep and the air to water setup doesnt have as much pressure drop as ur old air to air

 

i was kinda thinking the same thing about less pressure drops. Less piping that the turbo has to pressurize. but i was looking for ideas of a quick fix rather them getting a larger wastegate.

I am hitting boost cut. I was watching the boost gauge on a few of the runs and it shoots up really fast, not like a slow creep passed my set boost. I set boost ut at 6.5 and when datalogging thats where i can see it is stopping at.

the IATs dont play a big role in this problem. they are about the same as when i had the front mount on the car. the front mount only had higher IATs when driving around for a few hours and the front mount got heat soaked. I had to do a little bit of part throttle tuning, but boost AFRs and IATs are the same.

even on and off 1/4 throttle, I can hear the wastegate open, but i am not sure if its not getting a solid signal from the the turbo or if the wastegate just cant regulate the boost efficiently because of the lesser/ NO pressure drops.

 

why only run 6.5psi?...whatever motor it is should handle 10+psi with a good tune

 

i am in the testing phase and changing different setups. i dont want to run higher boost til i have a permenant setup. also my motor is 11:1CR

 

anyone going to chime in on this? or am i just stuck?

 

bump, thread got lost

 

try putting a new hose on it, perhaps your old one is melted shut.

 

I would check the signal line from the compressor to the WG. Partially blocked or leaking could cause this. I cannot imagine how a lower pressure drop or better IAT's would cause this, more resposnive yes, but not overboost. Good luck, if I think of anything else I will post back.

 

there is nothing wrong with the signal line to the wastegate, i actually replace it thinking that was the problem. i also check the fitting on the turbo/ wastegete for blockage. there is nothing wrong with the boost signal to the wastegate.

i have a new turbo manifold on the way, i havea feeling its because of the wastegate placement on that POS manifold that i have.