North American Turbocoupe Organization



More boost please
Hal Offline
Junior Member
#1
So I just installed a manual Boost Controller. I have not driven the car yet. I installed a t on the boost side of the manual Boost Controller and sent one side to the factory boost Control Solenoid The other side of the boost Control Solenoid I capped off. Should I of done this? Doesn’t the ECU still need to know the car is boosting? What does everyone else do? Any help would be greatly appreciated.
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Pete D Offline
Administrator
#2
Did you look at this article? It should help you sort this out. It doesn't matter if your manual BC is a Gillis valve or some other kind. Just get the circuity installed per the article. Good luck.
http://turbotbird.com/techinfo/GillisVal...sValve.htm
Pete Dunham


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Jeff K Offline
Administrator
#3
^^^^ +1

MBC does not use any T connector to the BCS. Leave the BCS completely disconnected. The BCS is not a sensor, it is just a flow control solenoid with no feedback to the PCM.

Unlike all modern turbo cars, the PCM has no way to directly measure boost.
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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Hal Offline
Junior Member
#4
That’s the info I was looking for. Thank you very much. I am more used to modern technology where the electronic boost control is also the boost pressure sensor for the ECU. So the stock solenoid must get the signal from the ECU to change the boost parameters? How does it do that without being a sensor also? Or is it just a one way sensor like you described?


Pete, yes I had looked at that article several times and I am still confused on where it says to keep the boost lines connected to the BCS. Are they just hanging there not connected to anything? Thank you both for your help.
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Pete D Offline
Administrator
#5
My understanding is that some of the parameters are fixed and activated by rpm and air flow (to the limits of the VAM). The code crackers report that the fuel trim is enriched at 3K rpm based on the "assumption" that boost will onset at that level and fuel enrichment will be needed for safe operation, as an example.
Pete Dunham


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Hal Offline
Junior Member
#6
So I took the the bcs out of the loop and went straight manual Boost Controller. Took the car for a ride and now Its running a solid 17lbs of boost. Mind you I have no restrictions on either the intake side or exhaust side and there is no power steering pump or a/c compressor. I do have an upgraded fuel pump also. I have the manual Boost Controller set at 0 so there is no lower boost I can run.
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anasazi4st Offline
Senior Member
#7
Hal Wrote:I am still confused on where it says to keep the boost lines connected to the BCS. Are they just hanging there not connected to anything?
I remember reading somewhere that the reason you don’t completely remove the BCS or its hoses is because it’s old and fragile and likely would break or shatter when you tried to remove the hoses, and what if you later on wanted to reconnect it? (Although—as you’ve seen—why you would EVER want to go back that inefficient system with its weak boost is beyond me!)

The instructions that come with the Gillis valve tell you to disconnect and remove it completely.
Another proud dues-paying member.

1987 Turbo Coupe w/T5OD, 8.8 axle, grey smoke; most options. Got it in 1991 with 41K miles: 3 turbos, 2 heater cores, 1 T5OD full rebuild, 5 clutches, 1 head gasket, 2 Teves II ABS units, etc. later....
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Jeff K Offline
Administrator
#8
Recheck you installation. You should be able to set the MBC for any boost level higher than the WGA / WG setting, which should be 9.5 psi or so.

The stock boost gauge is notoriously inaccurate. Are you going by the stock gauge or a good quality aftermarket gauge?
Jeff Korn

88 Turbo Coupe: Intake and exhaust mods, T3 turbo at 24 psi, forced air IC, water injection, BPV, Ranger cam, subframes, etc., etc.
86 Tbird 5.0 (original owner): intake, exhaust, valvetrain mods, 100 HP N2O, ignition, gears, suspension, etc., etc.
05 Taurus SEL Duratec daily driver
04 Taurus Duratec (wifes car)
02 Pontiac Grand Prix GT
95 Taurus GL Vulcan winter beater
67 Honda 450 Super Sport - completely customized
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Hal Offline
Junior Member
#9
I have an auto meter vac/boost gauge installed. 30inch vac 20psi boost. I was going to manually check the setup with just a pump to see at what psi the wastegate opened up. The high level of boost seems wrong to me also. I would of thought the boost should of stopped around 10psi also. I am going to put the T back in the loop at the wastegate to see if that might make a difference. Maybe my port off the turbo that I am getting the boost pressure from isn’t working? I’ll have to pull from the intake manafold for boost if the turbo port isn’t working. The car was only running 9psi before I removed the bcs. I did read that you should get the boost closets to the turbo and you shouldn’t get it from after the throttle body?
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Hal Offline
Junior Member
#10
So I pulled the vac line for the boost feed for the mbc and put pressure on that line. Come to find out I actually had the boost controller set to max boost not less boost(diagram on controller is misleading). Will take car out for a spin again and let you know how it runs. Would like to keep it at no more than 15psi. I have the timing set to 11 degrees so trying to keep it rather safe but plenty of power. Thanks again everyone for
Your help. Merry Christmas everyone.
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