I was taking my car out for a spin today and when I was winding it out in 3rd gear, the car overboosted and hit 29 psi.

I messed around with the boost control settings a little. It was originally set to open loop boost control where the solenoid duty cycle was set at 40%. Until today the car never had any sort of problems overboosting. Just to try a few things out I set the duty cycle to 0% which should mean wastegate spring pressure (~12 psi) but it still ended up hitting 29 psi.

I even changed it to closed loop and set it to a ridiculously low setting and it did exactly the same thing.

I did a quick look at the vacuum hoses and they all looked good. Solenoid wiring was ok, and the wastegates are still dumping open at about 18-20 psi so I know they arent stuck closed or anything.

Anyone have a clue?

 

Why don't you have your overboost set up? That is scary. I am boosting (Haltech conrtoling boost) about 8psi and my overboost limit is 10psi.


Sonds like a kinked hose to me, but you said you checked them all.

Good luck.

 

overboost is set at 29 psi, its safe at 29 psi I just dont like hitting that fuel cut ever time I floor it.

Any idea what the symptoms of a stuck / broken solenoid would be?

 

I see.

Disconnect the solenoid from the haltech, and try to cycle it by grounding one wire, and touching the positive terminal of your battery with the other. Polarity is irrelevant as it is just a coil being energized.

You should hear it clicking every time your touch/remove the one wire from your positive terminal.

 

Ill try that tomorrow, im also going to try and disconnect the line that goes to the top port of the wastegate to see if it will boost at spring pressure only. that way i can isolate the problem more

 

That overboost fuel cut is nasty. I agree with the above, it's the wiring, boost solenoid, or the hoses. I would predict a hose has been cut or burned through or has a crack. It can be VERY hard to see a crack in those hoses without flexing the hose unfortunately. Any way for you to pressure test the boost reference hose? Maybe just run another one.

 

good thing this subject came up, my issue is that when ever i have my car sit for a while and at first my duty cycle was around 35%. had to increase it to hit target again.

last thing i did on my car was to change the flywheel back to stock cuz my JWT flywheel thread bolts where the clutch bolt to are lose. so i used the stock. after break in 4th i only saw 11 psi when i tuned it to 14psi. will the change in flywheel affect the car that much.

 

Turns out a vacuum tee broke off and I didn't even notice it till I put air in the system

 

glad you got it figured out.