Boosting too high

[2gPressure]

Installed a boost controller today, connecting it to turbo outlet housing and wastegate. left boost solenoid unhooked. The boost controller is set at nothing and it is boosting the same as before this. Starts at 18 psi, then around 15 most of the rpm band and then down to 12 at 7,000 rpm.

 

[2gPressure]

I almost think the wastegate isn't working properly

 

[2gPressure]

At least has anyone installed a boost controller and set it all the way out to open?

 

[karbon]

At least has anyone installed a boost controller and set it all the way out to open?

I don't have the balls for that. My turbo would get to 38 psi or so. My engine would be long dead before that.

 

[2gPressure]

i meant open as in the other direction. so that there is no or as little boost as possible. i'm boosting 18psi like this. i wouldn't do that either. I have a friend that did that on a 1G and it pulled like a raped horse. for an hour of rapage and knocking then the only thing that happened was a throw out bearing went bad

 

[Burnett03]

Installed a boost controller today, connecting it to turbo outlet housing and wastegate. left boost solenoid unhooked. The boost controller is set at nothing and it is boosting the same as before this. Starts at 18 psi, then around 15 most of the rpm band and then down to 12 at 7,000 rpm.

1st question is why are you getting the source from the compressor outlet instead of the manifold? it a better, more stable pressure source.

 

[2gPressure]

I was going to hook it up that way. But it should be close to the exact same pressure and the stock car uses that nipple outlet for the exact same purpose. Plus it said to do that in the Hallman instruction manual. I figured what the hell it's easier that way too. i'm not thinking that is the cause of the problem though especially when at full throttle they are basically the same point with the same pressure

 

[oldman]

I was going to hook it up that way. But it should be close to the exact same pressure and the stock car uses that nipple outlet for the exact same purpose. Plus it said to do that in the Hallman instruction manual. I figured what the hell it's easier that way too. i'm not thinking that is the cause of the problem though especially when at full throttle they are basically the same point with the same pressure

The pressure at the turbo outlet and the manifold should be very close unless you have a huge boost leak some where in between so I agreed that it shouldn't have caused the problem you're having. This is what I would do.

1. Make sure the pressure souce is hooked up inline with the adjustment knob and the T fitting goes to the actuator.

2. Bypass mbc by running the pressure hose directly to the actuator. If boost holds firm at 10 psi, either you hooked up the mbc wrong or you have a bad mbc. If problem persists, perform a boost leak test and fix all leaks.

Good luck.

 

[2gPressure]

So the wastegate actuator is set to go off at 10 PSI? the stock 2g wastegate actuator that is

 

[oldman]

So the wastegate actuator is set to go off at 10 PSI? the stock 2g wastegate actuator that is

I'm sorry but I'm not sure about the T25 but whatever it may be, the important thing is whether you get a solid steady boost without fluctuations.

 

[Thomas91169]

its a t25. nuff said.

hes spiking at 18, then settling down to 15 then its puttering out to 12 at redline. sounds like a t25 to me.

 

[BGRIPTP]

its a t25. nuff said.

hes spiking at 18, then settling down to 15 then its puttering out to 12 at redline. sounds like a t25 to me.

Thats what I was thinking also, the T25 sucks at holding boost.

 

[2gPressure]

I was more or less trying to find a way to turn the boost down so im not running the T25 to it's limits all the time. Apperently there is an aftermarket wastegate actuator on the car, unless that is how the stock wastegate actuator works. And a boost controller can only increase boost

 

[tstkl]

2. Bypass mbc by running the pressure hose directly to the actuator. If boost holds firm at 10 psi, either you hooked up the mbc wrong or you have a bad mbc.

wait so what the hell does the boost control solinoid do if the stock wastegate is set to 10 psi... i figured maybe its like 7 or like 5 and the boost control solinoid works like a manual boost controller that the ecu controls or something...(its electronic,...)

 

[psychlow]

Stock is around 10PSI. The BCS will bump it to between 11 to 14 depending on the car, as long as you're not knocking.

If you want to run less boost, source your compressor outlet straight to the wastegate actuator and take out the BCS and MBC.

 

[truwarrior]

try a thicker vac line from the source and to the wastegate

 

[oldman]

unless that is how the stock wastegate actuator works. And a boost controller can only increase boost

That is how turbo/actuator/mbc work. Actuator sets the minimum boost level, mbc increases boost level by delaying the pressure from reaching the actuator.