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Boost problems

 
Old 05-29-2018, 02:31 PM
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Default Boost problems

Hey all,
So I would like to start out by saying I am stumped, and I hope it is something really simple that I am over looking. I am having issues of not being able to maintain boost pressure. It's a tial v60 gate, Hallman MBC. I thought the spring pack that came with it was 12 psi, but it turned out to be 6 psi. So we changed the spring to a 15 psi spring. My problem and my confusion is this, even with a 6 psi spring, the boost controller should be able to hold more than the spring pressure, I read somewhere it should be able to hold 150 % of the spring pressure, which would've been around 9 psi. But that wasn't the case, it was only making 5-6 psi, we changed the spring to a 15 psi spring, and it made 15 psi even with the boost controller maxed out.

So what am I doing wrong, do I not have enough manifold/line pressure on the wastegate diaphragm to keep the wastegate closed? The wastegate is setup with the source coming from post throttle body, to the MBC, to the side port of the wastegate, top of the wastegate is VTA. Do I need to go with an electric 3 port boost controller which would utilize both ports on the gate?

Because shoving a socket in the wastegate to get some more psi out of it probably wasn't the best idea, she shot up to 27-28 psi real quick before blowing my coupler
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Old 05-29-2018, 02:34 PM
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my .02: hallman comes with 2 springs. from my exp anything over 14-15psi and you need the heavier one. (the Subaru turbo's I usually tune have a 10psi wga).
Also a monster gate like that you probably want a larger than the standard 5/16 vac line.

If you want it rock solid no matter what, time for a 4port mac valve and set up both ports
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Old 05-29-2018, 03:29 PM
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Originally Posted by 18psi View Post
my .02: hallman comes with 2 springs. from my exp anything over 14-15psi and you need the heavier one. (the Subaru turbo's I usually tune have a 10psi wga).
Also a monster gate like that you probably want a larger than the standard 5/16 vac line.

If you want it rock solid no matter what, time for a 4port mac valve and set up both ports
I'm running 1/4" push lock fittings on everything. I have no issue going away from the manual boost controller. Obviously going EBC would provide more control and adjustability, just need to get it set up in the ecu. That's interesting though, I didn't know that boost controller itself had different sized springs. You gonna tune this thing for me?
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Old 05-29-2018, 03:43 PM
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haha, I'm genuinely scared just looking at your car. I thought its already tuned? I see it rippin around going 1000mph

Most/All modern standalones can control a 4port mac valve without any issue. But I'd try the spring first because its like 30 sec to swap. I have one too if you wanna borrow
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Old 05-29-2018, 03:56 PM
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Originally Posted by 18psi View Post
haha, I'm genuinely scared just looking at your car. I thought its already tuned? I see it rippin around going 1000mph

Most/All modern standalones can control a 4port mac valve without any issue. But I'd try the spring first because its like 30 sec to swap. I have one too if you wanna borrow
lol no, it hasn't been tuned yet. I am using a basemap from Holley that I adjusted the injector size and have been running it. I don't really plan on running this car until late September/October, so if going with the Mac valve is the right way to go, might as well do it now
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Old 05-29-2018, 03:58 PM
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If holley has boost by gear or boost by speed, or any modern boost control, I'd say yes definitely. Even on my weaksauce 400hp Subaru I utilize this, I can only imagine how much helpful it would be on your nasty beast.
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Old 05-29-2018, 04:49 PM
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Originally Posted by 18psi View Post
If holley has boost by gear or boost by speed, or any modern boost control, I'd say yes definitely. Even on my weaksauce 400hp Subaru I utilize this, I can only imagine how much helpful it would be on your nasty beast.
It does have all that fancy stuff; boost per gear, mph, RPM, and TPS. I think it would be fun to hook up a scramble button for an extra 5 psi on demand
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Old 05-31-2018, 12:50 PM
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So you are saying your wastegate signal is coming from the intake manifold which is post throttle body, correct?
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Old 06-01-2018, 03:04 PM
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Originally Posted by sixshooter View Post
So you are saying your wastegate signal is coming from the intake manifold which is post throttle body, correct?
That is correct, I made a distribution block which is fed by a 3/8 nylon line post throttle body. Then the BOV, wastegate, FPR, and boost gauge are all feeding off that distribution block. The MAP sensor has it's own dedicated signal line
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Old 06-01-2018, 03:12 PM
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Might wanna source pre-tb so you don't overspin the turbo at part throttle, though it's not a huge deal in your case either way.
(is your LS drive by wire?)
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Old 06-01-2018, 03:13 PM
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I had the the biggest trouble with my ebc solenoid, and could not reliably calibrate it to hold boost correctly.
It shared the same vacuum line with my BOV using a Tee.
I gave my BOV and EBC solenoid their own vacuum lines and problem solved.
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