Help with MBC, cant add more boost
#1
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So last night I tried to turn the boost up, here is the boost controller I have
http://www.jegs.com/webapp/wcs/store...0002_315228_-1
Also there are 9psi springs in the gates
First we turned it up 6 clicks, and the boost went up a little, next 6 more clicks, nothing, then 10 more clicks, nothing.
Here is how we have it setup
Manifold Pressure ---> Boost T ---> T --( two lines )--> Waste Gates Low Side
AFRs were in the 11.4 area timing 20deg
http://www.jegs.com/webapp/wcs/store...0002_315228_-1
Also there are 9psi springs in the gates
First we turned it up 6 clicks, and the boost went up a little, next 6 more clicks, nothing, then 10 more clicks, nothing.
Here is how we have it setup
Manifold Pressure ---> Boost T ---> T --( two lines )--> Waste Gates Low Side
AFRs were in the 11.4 area timing 20deg
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Depends how the gates are mounted as to top/bottom...lol...
The port in the center of the removeable cover should be vented to air.
The other port takes the pressure reference.
The port in the center of the removeable cover should be vented to air.
The other port takes the pressure reference.
#6
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Originally Posted by Boostaholic
Here is how its hooked up
Tial's website shows the line coming off the top of the gate goes into the MBC, then the outlet of the controller goes into a T where it joins up with the line for he side of the gate. The T also has a reference line to anywhere on the pressure side. Check this out and click on wastegate install diagram:
http://www.tialsport.com/techincal.htm
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You may be overcoming the 9lb spring if you have a lot of exhaust pressure. Meaning that the wastegate may be opening solely because of that. What you CAN do, and I stress that this would have to be done EXTREMELY carefully, is just to test, pull the boost reference off the wastegate. Then slowly get into boost... if you see the boost going higher than you want, let off right away. If the boost goes higher than it would with the MBC attached, then the spring is not your problem. HOWEVER if boost will not go any higher that what it was with the MBC connected, the you are pushing open the wastegate with the exhaust and need stronger springs.
Once again be EXTREMELY careful if you decide to test it in this manner, and I take no responsibility if you overboost and blow stuff up
Once again be EXTREMELY careful if you decide to test it in this manner, and I take no responsibility if you overboost and blow stuff up
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Run a bleeder type regulator to the top of the gate. We ran references from the turbo outlets (or in your case the manifold) directly to the side (which is what is normally reffered to as the 'bottom' of the gate). Then we ran a simple Turbonetics manual boost controller off of manifold pressure to the top of the gate (the one you currently have open to atmosphere). All it does is bleed off some of the pressure and put the rest on the top of the gate which makes it harder for your bottom/side port pressure source to lift up the valve (ie more boost). My pressure never varied more than a half psi once we got to the regulating point.
Hydrostream is on the money with the exhaust back-pressure unseating the valve.
The one you have now acts a lot differently because it doesn't allow any pressure to pass until you get to the threshhold you have it set to. This means if you have enough exhaust back-pressure, you will unseat your wastegate valve and be unable to make any more boost.
Hydrostream is on the money with the exhaust back-pressure unseating the valve.
The one you have now acts a lot differently because it doesn't allow any pressure to pass until you get to the threshhold you have it set to. This means if you have enough exhaust back-pressure, you will unseat your wastegate valve and be unable to make any more boost.
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Originally Posted by Boostaholic
ok ltl im going to go give it a shot in a bit here, just leaving the office in a few minutes.
thanks for the tips
thanks for the tips
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It did not work, so I unhooked the bottom ports on wastegates and it still only just came up to 10.
I'm pretty sure at this point I have a big exhaust leak in one of my gaskets some of the bolts are loose on the driver side manifold I noticed after I thought about exhaust leaks.
I'm pretty sure at this point I have a big exhaust leak in one of my gaskets some of the bolts are loose on the driver side manifold I noticed after I thought about exhaust leaks.
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Originally Posted by HydroStream6
I'd be willing to bet you're pushing the WG open... how much boost do you want to run? A 9psi spring vs a 1 bar spring is a HUGE difference in resistance, and will probably solve your problem as long as you can run ~1 bar or more all the time.
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Yep, Chris.
Also got the new exhaust gaskets so I think I'll put them on too and see what it does.
It also seems like its spooling a lot slower than it did last year, but I could just be getting used to things too. Kind of like how my R1 felt insanely fast when I first got it but now its just normal.
Also got the new exhaust gaskets so I think I'll put them on too and see what it does.
It also seems like its spooling a lot slower than it did last year, but I could just be getting used to things too. Kind of like how my R1 felt insanely fast when I first got it but now its just normal.