I am having some trouble with the boost controller keeping boost. The WG spring is 10psi and I get 8-9psi from it alone but when I energize the controller it goes to 12psi then back down to 8 then back up again. I talked to AEM about it and they said I had a bad solenoid so I bought a new one but the problem is still there.

What could be causing this issue?

Here is how I have it wired.


You can hear the exhaust note change when the low-high boost kicks in in this video if you listen carefully. I also have a HPT scan showing it.

 

Sounds like your SPr setting in your setup is too high. Have you watched this video?

Goes through the setup process for your SPr setting on the Tru-Boost. It may be your issue.

 

I have seen that video several times and spoken to AEM about it. I have tried to lower it all the way down and it still does it that is why they suggested I buy a new solenoid.

I was told to tap both compressor wheels instead of just one(how I have it now) to see if that would help.

A buddy of mine has the E-Boost and he uses two solenoids on his TT setup and suggests that but I don't see a dual-solenoid diagram on AEM's website.

 

I'm tapped out. Sorry I can't help you more.

 

Is the gauge reading pressure at one of the compressors or the in tank Mani?

 

what duty cycle do you have it set at when it does this? how much boost are you trying to run?

 

I tapped one of the compressor wheels for boost reference.

10% and it gives me a max of 13psi. Once I get it working properly the goal will be 5psi(WG spring), 10psi(setting A) and 15psi(setting B). Plus, scramble set for 10% if meth fails or 20psi when on race gas only.

 

try leaving the compressor hooked to the solenoid but reference boost at the intake manifold

 

I would consider referencing port 1 and your boost gauge reference from the manifold vice the turbo.

Also could be a problem with a leaking diaphragm in the wastegate or an improperly sized wastegate. Since I don't know specifics of your setup.

 

i had the same problem when i tried to run a low duty cycle. change the wg spring to a softer spring and turn the duty cycle up.

 

If I understand you correctly then that is how it is currently connected. The compressor is hooked to Port #1 on the solenoid but the boost reference for the gauge, controller, meth, fuel pump Hobbs switch etc. are hooked to the manifold via a Vibrant vacuum manifold.

Or do you mean hook the compressor to Port #1 on the solenoid but hook the WG lower port to the manifold.

Wouldn't that increase my boost when the controller is off? On other setups when switching from referencing the compressor vs the manifold I would get the boost I was loosing to the piping and intercooler.

BTW, the specifics are a 416ci(9.28cr) with twin Garrett/FP HTA3586R’s with dual 3" DP's. Twin TiaL MV-R 44mm Wastegates and a single TiaL “Q” Blow-off Valve.

I tried that on the old solenoid but not on the new one yet. The WG has two springs in it that add up to 10.15(one is 5.80 and the other is 4.35) so I removed the 4.35 spring and was getting 4-5psi on the 5.80 spring. Using the controller at 10% DC was netting 7-8psi but was surging back and forth from low to high.

I might have to try all the different ways the Turbosmart controller is hooked to see if one works on this app.

 

Here is the setup.

 

turn the duty cycle up.

 

This is probably your problem. They need to be hooked up to the same spot otherwise the reason it's going up and down is you are reading the lag in response when the gate opens and needs to reset/settle at the right level. Springs have what's called accumulation and blowdown..which in basic terms means the set pressure is not when the gate opens or shuts. If you had a turbo shaft rpm log you'd see easier what's happening.

Like dudeman said if you are able to use a softer spring they will respond quicker and there will be a smaller margin of error for the accumulation and blowdown. Also by running the solenoid at a higher duty cycle you create a larger potential D/P aross the valve when it does open which causes it to respond better.

 

Also if you haven't already, you definitely need to put zip ties on your vacuum lines and especially to the wastegates, that will cause the wastegates to respond slower too, not to mention possibly completely blowing off a line.

 

So you are saying to cap off the nipple at the compressor cover and use the reference from the vacuum manifold. I will try that but I don't see how that would help. The solenoid is duty cycle operated so it doesn't care about boost pressure. If I set it at 10% DC it cycles the solenoid 10% regardless if it gives me 5psi or 20psi.

I will also try to go back to the softer(5.8psi) spring and see if that helps. That is the spring I want to run permanently so I can go 5, 10 & 15 using the controller. Switched it back only because it was oscillating between 5 and 10psi.

Yes, definitely. In the pic above I hadn't yet installed the boost controller. It blew off the lines at 16psi so when I installed the controller I used worm gear clamps on all the connections.

thinking of going hard line so I bought some SS line and all the AN fittings but wanting to fix the problem first.

 

Installed the second solenoid and replaced the rubber lines with SS ones with AN fittings and it still surges.

So running two solenoids one off of each compressor wheel. Maybe its the gauge?

 

what duty cycle is it at now?

 

I thought I had a bad solenoid so I replaced it and still didn't work. Then I went ahead and used both and it still surges. So, I never lowered the WG spring from 10 to 5 psi to test it with a higher DC on the solenoid. It is still at 10% setting A and 15% setting B.

Hesitant on lowering the WG spring in case it doesn't work because then I will be stuck on low boost and you never know who will be in the lane next to you, hahaha. And it sucks having to crawl under the car to make changes. It is easier to switch solenoid ports then to open up the WG and remove/change springs. Plus, I tried that before with the old solenoid and it still surged.

I am going to redo the install using the Turbosmart single port twin solenoid twin turbo setup. If that doesn't fix it then I will remove a WG spring and try using higher DC on the solenoids.

Any other suggestions?



So this is how I had it hooked up before with the single solenoid:



And this is what it was changed to with dual solenoids:



And this is what I want to try per Turbosmart instruction:

 

Well, I called AEM and they said not to use two solenoids as their unit wasn't designed to run two only one. Since it wasn't a bad solenoid they suggested I look for a leak before I go any further. All the lines were redone in SS with AN fittings so it's not that but they told me to remove the waste gates and check them for leaks. They said to blow air on the bottom and top ports and that no air whatsoever should come out.

If it isn't that I'm going to throw in the towel and just replace the Tru-Boost with a E-Boost 2. But it might be a while so for now I will just put another spring in there to increase boost to 13psi.