In tuning my car; I went over the datalog and the engine hit 17lbs of boost. The WG springs are 7.5lbs. I'm running on the springs only. The WG's are 38mm Precision units with one natural and one red spring in each. (Dual WG's). Springs are new from Precision.
How the heck is boost climbing to 17lbs of boost on such light spring pressure?
Thanks.

 

Is the WG vented to allow air to escape or is it plugged off?

ks

 

Vented out the top.

 

To be that far off, i'd be looking at placement, or signal leak.

 

Thanks. I hope it isn't placement. I'll check the hoses again.
Thanks.

 

For reference; here's my setup. Does this look okay?

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Wait, you have a boost controller?

 

Yes but it's disabled in the tune right now. I was having issues with spark blowout at higher rpm's so my tuner turned off several things to rule them out. I replaced the coil and took the car for a run. The spark blowout was cured but the boost went through the roof on springs only. This concerns me as I see this being a safety issue if a hose blows off or the boost controller fails.

 

Bypass the controller just to rule it out. Plumb lower gate ports to the compressor housing or other pre throttle body/intercooler source.

 

Will do and thank you.

 

Is your boost controller in line to the bottom of both wastegates? Boost controller is turned off now?

If my thinking is correct, with the boost controller off, no pressure is getting to the bottom of the wg? If that is the case, you will get higher pressure for sure.

If that's how you have it plumbed, put the boost controller to full duty giving full pressure to the bottom of the gate.

 

You should plumb it so that 0 duty cycle is lowest boost, and you have to add duty cycle to increase boost.

 

Typically with ebc's, the top ports are used, so you'll want to verify it's plumbed correctly. It looks odd. I would still bypass to start, and then move on. Be cautious with the controller, if you don't have boost cut, and stuff isn't right, things can get out of hand, and damage can, and has been done.

 

Yes; controller is off.
If I blow through the turbo inlet fitting on the controller; air comes out of the WG fitting on controller.

 

That is how it's currently plumbed.

 

I did a lot of research on that and came to the conclusion that the bottom ports should be used with a 3 port controller.

 

It may work with just the lower port, but it's not very effective, especially with a low psi spring. This is what I typically associate with a 3 port, which uses both. If only using the lower port, all it's doing is venting the signal. The lower is usually always used, and the upper is used for control. #ad

 

I've seen that illustration before but didn't see that it pictures a 3 port controller. I may try that. I just tested the spring pressure with a coolant pressure tester. The combo of the natural and red spring cracked open at 7.5 and closed at 16. Crazy! I now removed the natural spring while leaving just the red spring installed. It cracks around 5 and closes at 10ish.

 

One of my tricks for safety is use a gate spring that when the vacuum hose blows off, will give you a safe net boost pressure

for example I used a 3psi spring in 44mm gate for max 500rwhp control back in 2020.
Without the vacuum hose attached to the gate (NO hoses at all) it would 14-15psi of boost maximum which is safe. One time the hose DID blow off and it was great, I just kept going.
The exhaust gas pressure lifts the gate by itself.

Controller wise a 3-port could raise 3-psi spring to 13.5 to 14psi with reasonable exhaust pressure assistance. The car kept doing 490rwhp over and over and then I got sick of that and pulled the vacuum hose off and wham 530tire just a psi or two extra.

A 4-port controller solenoid could theoretically rise much higher- I never tried it though.
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Anytime a controller attempts to control the bottom port of an external it worrys me. Maybe I'm just more comfortable with the 3port because its what I've always used for 20 years though.