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ΣΦE
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Discussion Starter #1
Just got a greddy profec-b specII installed and I can't get anything lower than 17psi. Even with the ebc off running off of the wastegate I'm still getting 17psi. All appropriate VSV's are capped and the ebc was tried on both actuators.

Mods are: stock twins in sequential mode, greddy fmic, apexi intake, hks ssq, rmm catless dp, apexi n1 catback, greddy bcc
 

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What do you mean 'all' appropriate VSV's have been capped? If you say the car is still in sequential mode, the only VSV that should be bypassed by the EBC is the wastegate VSV.

Also, there is only one actuator that the EBC is involved with, which is the wastegate actuator (the gold-ish colored one in front of the #1 turbocharger near the alternator.)

Please explain these things, as verifying the proper installation is the first step in troubleshooting.
 

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ΣΦE
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Discussion Starter #3
Sorry for the lack of information as I must have misinterpreted what my installer was telling me. He's a trustworthy guy and has worked in many supras so I'm sure it's installed correctly.

So if it's installed properly, any suggestions as to what could be causing the high boost?
 

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Check to see if he performed the spring mod.
 

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ΣΦE
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Discussion Starter #6 (Edited)
Check to see if he performed the spring mod.
He didn't perform the spring mod, he was kind of skeptical of it when I asked him to a while back. The 17psi is held pretty solid to redline though. Would the spring help with running lower boost levels?

He's never had this problem with the other supras he's tuned.

Stock USDM motor.
 

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Hardtopper
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I have a somewhat similar issue. I was straight BPU and then installed a Max-Air box and a GReddy 3-Row. I'm now not able to generally boost LESS than 16.5 - 17psi depending on the weather. At first I thought my EBC was bad (created a thread about it). After some troubleshooting/testing, I've come to realize it's pretty much 'normal'.
 

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Supra Owner
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I would say its pretty normal. I know 2 BPU supras that seem to do the same thing after going EBC, Downpipe, 3 Row intercooler, and intake. I think the turbos are breathing alot easier.
 

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ΣΦE
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Discussion Starter #9
I have a somewhat similar issue. I was straight BPU and then installed a Max-Air box and a GReddy 3-Row. I'm now not able to generally boost LESS than 16.5 - 17psi depending on the weather. At first I thought my EBC was bad (created a thread about it). After some troubleshooting/testing, I've come to realize it's pretty much 'normal'.
I don't mind it boosting 17 until I move out to Nevada in July where they only have 91 pump max. So somehow I need to find a way to lower it! Think a high-flow catalytic converter may restrict it?
 

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...Think a high-flow catalytic converter may restrict it?
Yes. Or if you don't want a cat, use an exhaust restrictor like the JDM turbo users do.
 

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I don't mind it boosting 17 until I move out to Nevada in July where they only have 91 pump max. So somehow I need to find a way to lower it! Think a high-flow catalytic converter may restrict it?
Why don't you just a piggy-back ECU or a stand-alone and tune your fuel maps accordingly to 17psi?
 

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ΣΦE
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Discussion Starter #13
Yes. Or if you don't want a cat, use an exhaust restrictor like the JDM turbo users do.
Hmm... I might just go with a high flow cat since I'll have to deal with smog and all that out west. Maybe it'll help cut down on me smelling like exhaust fumes when I get out of my car also LOL!

I would just go with a MBC for the stock twins.
I had a manual boost controller but having to deal with desert climate I figured an EBC would keep the boost the same level no matter the temperature. I hated adjusting the mbc every winter/summer in Virginia but in Nevada its hot in the day and cold at night.

Why don't you just a piggy-back ECU or a stand-alone and tune your fuel maps accordingly to 17psi?
I just didn't see a need for that kind of control at just bpu levels, esp since supras don't need to tune per mod/boost like other cars. I wanted to have the EBC control boost even when I went with a piggy-back/stand-alone for simplicity purposes.
 

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what you are experiencing is called boost creep, it's duo to having small waste gate that can't keep up with the fast/free flow exhaust and bleed the pressure fast enough.
what I have done to overcome that problem is install a 2" flange or something similar with smaller than the exhaust pipe inner diameter opening and stick/bolt it between an existing flanges in the exhaust pipe before the muffler, the idea here is to restrict the exhaust flow a bit to allow the tinny waste gate do its job.
 

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ΣΦE
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Discussion Starter #16
Yes. Or if you don't want a cat, use an exhaust restrictor like the JDM turbo users do.
What exactly is the exhaust restrictor that the JDM turbo users use?
 

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I forget the exact size, but it's like a plate installed in the exhaust system with a 2" hole in it
 

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ΣΦE
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Discussion Starter #18
So basically what XTsupra was talking about. So I could just place this flange b/t the downpipe and catback or does it need to be closer/further from the turbos?
 

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If I was using it I would tend to put it at the flange at the front end of the downpipe but I doubt it makes much difference at the back end like you said.
 

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I have mine installed right before the muffler for ease of installation and I can lower the boost to as low as 0.7 with no spikes or creep at all.

good luck
 
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