Super Slow SS

iTrader: (9)

*****Solved*****


Okay so as the title says I have been having this problem for some time now but haven't been driving the car so it really hasn't bothered me.

I have a AEM TruBoost, it is connected correctly, verified by 2 shops and the manual several times. The wastegate spring is 8 psi which makes about 7. The gate holds the turbo find and it does not spike or over boost.

When I turn the BC on the lowest setting (10) it does not hold the turbo below 11psi, it may be higher but I have the tune messed up at that level so it doesn't hurt anything. Could it be a bad solenoid? Or is there some odd way to set it up that I don't know. It will hold it at or above 11 psi if I stay in it, doesn't just spike there.

I would love to be able to set it to about 9-10 psi but can't seem to get it down there and would hate to buy a manual boost controller and just use this thing as a gauge.

Super Slow SS

iTrader: (9)

I see this didn't get anywhere so here comes maybe the longest bump ever?

SPRAYED 01

iTrader: (22)

Your lucky,i cant get my boost over 11psi. Same controller with 11lbs spring. I think the solenoid is bad. Yours might be stuck slightly open. What waste gate?

MaxxMitchell

iTrader: (15)

Pressure check your solenoid. Also double check for leaks at the fittings on the solenoid, boost source and at the wastegate. I have used several of these and never had this issue.

Do you have the boost source Y'ed off having one line go to the bottom port of the wastegate, then another going to the boost solenoid that adds pressure to the top port? If so a slight leak in the solenoid could easily cause your problem. Another thing to check is to make sure your vent is not clogged on the un-used port on the solenoid.

Super Slow SS

iTrader: (9)

Thanks for responding and I will give all of this a thorough check tomorrow and report back, I am sure I have hooked it up according to the book and checked it at least 10 times. But for reference how is it suppose to be hooked up? I know I am using reference from the intake for all of my boost reference lines including the gauge (which reads fine) and BOV, so the reference port of the W/G is t'd from that same source.

Also entire setup is in the sig.

Super Slow SS

iTrader: (9)

just double checked my vacuum lines ,

Solenoid 1- goes to boost reference (intake)
Solenoid 3- Air reference (filter)
Solenoid 2 - goes to top of wasegate
Side of wastegate goes to boost reference (intake)

lsxmalibu

iTrader: (50)

check what setting you have for the spring pressure, if its too high it will keep the solinoid open and cause the wastegate to not open

Super Slow SS

iTrader: (9)

Will do, but I don't think I have ever changed it. I have to break the book out to figure out how to get back to that menu.

lsxmalibu

iTrader: (50)

i took my tru boost off and got a $20 brass nxs manual boost controller, it works great,

black06g85

iTrader: (6)

you will have to mess with the spr setting, you will have to run it lower than waste gate spring pressure.
That adjusts the boost level that the wastegate starts to crack open, and you need to run that low so it won't spike.
I've had to run it down to 4.7 on a 7lb spring in my last car to run just over wastegate pressure.

Super Slow SS

iTrader: (9)

Yes I have seen this elseware and thought I would give that a look, haven't been able to get around to checking what the setting is on mine yet though, but I have never changed it so I assume its on 1 by defalt? and it doesn't spike, it never comes back down lol. But for sure I will look at this tomorrow, hopefully I can get the car back to RPM for a 10 psi re-tune when I take it up in a few weeks for the inspection

98Z28CobraKiller

iTrader: (17)

Neither of those reference ports should be going to the intake. They should both be going to the compressor cover.

Super Slow SS

iTrader: (9)

Right, but I am using the intake as a "true" boost reference point as the compressor will often read 1-3 psi lower than actual intake pressure due to loss across the I/C and other factors, I have always used the intake. Would this cause a problem with the controller?

98Z28CobraKiller

iTrader: (17)

Right but those references are not going to a MAP sensor, correct?

They are being used as a pressure source on the wastegate. There is more pressure at the compressor than there is at the intake unless you have the worlds most efficient intercooler.

Super Slow SS

iTrader: (9)

Super Slow SS

iTrader: (9)

You sir are a prophet, turns out the SPr was set to 11.5, changed it to 5 turned the gain up to 40 and achieved 8 psi lol but right now it is at 6 and 50 and running a little more steady at 8, seems like a lot of gain to get 1 psi over the spring, and it seems to jump around quite a bit where as on the gate it would get to 7.1 and stay there, now its jumping from 7.5 -8.2ish constantly, more tweaking to do with it but it seems to finally be responding

Thanks, to everyone in this thread who has helped.

lsxmalibu

iTrader: (50)

does it feel like its surging...? your fighting the spring in the wastegate, take the spr pressure number lower.

if your bored watch the 4 videos on youtube AEM made to walk you through the way it works.

this is why I got the manual controller,,,,

Super Slow SS

iTrader: (9)

it seemed the lower the SPr the more it jumped around, but once I get some more time I will tweak it some more, it has been raining all day today, and I have watched the vids.


With the settings above it seemed to spool much slower than it did with the controller off.