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Life begins @ 30psi....
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2,369 Posts
Discussion Starter #1
Hey guys if anyone has any input please chime in here.

I have continued to fight boost control issues since day one with my car. Initially the boost would drop by a good amount in the upper revs (2-4psi) so I bought a EVC6 and got it all set up and the boost was ROCK steady in the testing before the Texas meet in March. I was only boosting to 21psi or so but and everything was perfect, the boost hit its mark as I set it and it only dropped off like 1psi from 6500 to 7600rpm.

I then parked the car and proceeded to get it ready for the meet I filled the tank with C16 and set the AEM's fuel cut higher boost. I was hoping to hit at least 30psi in Texas and maintain it while running C16. Well on the way to the dyno of Friday morning I set the boost controller to 30psi and let it eat on the tollway a few times and the most it would make was 24-25psi MAX. I was like totally pissed that I was still fighting this issue so I then said the hell with it and maxed out the boost controller to 36psi and hit again and to my dismay the car would only make 27psi or so. After some discussion it has been decided that my WG spring was just to soft for me to make 30psi and hold it, I had a purple 14.2psi spring in it FYI. I ordered the gray 18.5psi spring and I installed it tonight and I noticed 3 things that seemed odd and maybe contributing to my issues.

1. The orange diaphragm inside the gate was little twisted up on it self, I did pull it up and straightened it, I also checked it for tears and I did not find anything so I got it all positioned correctly and then installed the 18.5 spring.

2. I put the hoses back on it and started testing the gate with my compressor and when I put pressure to the middle port on the gate it opened like normal but there was a little air coming out the top port of the gate. It was not much but it was noticeable.

3. forcing air in the top of the gate kept it forced closed and there was a little air also escaping from the center port just as I would have suspected.

Do you thing the heavier spring would solve my issues? and do you think the twisted diaphragm and the slight air that is bypassing is causing any issues?

Thanks,
Bob
 

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Life begins @ 30psi....
Joined
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2,369 Posts
Discussion Starter #3
Jason -

I am running the 50mm HKS racing gate that comes with the BL stage 2 kit.
 

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Life begins @ 30psi....
Joined
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2,369 Posts
Discussion Starter #4
Ttt
 

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Boost4fun
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1,848 Posts
For me that sounds like the diaphragm must be damaged somewhere. I would just replace it and check the tightness then.
It is definitely not normal that air you are putting on the top nipple escapes (at least slightly) to the other one..
Just my 0.02
 

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Registered
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1,338 Posts
Check for boost leaks. Even the smalled leak can prevent you from holding boost. I pinched my O-ring on my Tial BOV flange and another small hole found at a pinched coupler. That's where I would start looking next.
 

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Supra Owner Since 1996
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2,723 Posts
Bob, I'm going to vote your on the right track. I had to do the same back in the day and my current spring set up has base boost @ 21psi on pump.
 

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Life begins @ 30psi....
Joined
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2,369 Posts
Discussion Starter #8
Alright I have the new spring in and I boosted tonight with it, the AEM's map sensor showing me hitting right at 18-18.5psi and everything is rock steady with the boost controller off. All seems to be ok for now and I just need to reset up the boost controller to the new spring and hopefully I will be good to go.

Bob
 
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