SP Boost Activated Exhaust Cut Out in Action!!
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Joined: Feb 2010
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From: Dekalb, IL
To be honest, I don't believe there would be any difference. For some more peace of mind, we are tuning a car in the next couple of days and I will see if we notice any difference in AFRs with and without the cutout being used.
Reid
Reid
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From: Bloomingdale, IL
I never notice any difference in the AFRs but the ProEFI compensates for backpressure changes. Even if it didnt I doubt that the AFR would change drastically.
Hmmm…this piece might work well with my turbo build…I’ve got a PowerLab GT35R kit and I’m planning on keeping the HKS dual exhaust, thinking about installing this cutout on the reverse Y pipe that’s needed...
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Joined: Feb 2010
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From: Dekalb, IL
That's probably your best bet. We discussed running this on my brother's built 300ZX and he originally wanted to run dual cutouts (he has a dual 3" exhaust) but Larry informed us that he can run a single and will actually make more power!! Cheaper cost and more output sounds like win/win to me.
I can get you a direct quote if you like. PM me or call my cell (in the sig) for more info and to discuss further!!
Reid
I can get you a direct quote if you like. PM me or call my cell (in the sig) for more info and to discuss further!!
Reid
its much cheaper to take 2 pulls on the dyno, one with the muffler and 1 without on the same tune before getting all wrapped up in this...
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Joined: Feb 2010
Posts: 148
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From: Dekalb, IL
You can go for that option too but on a boosted engine I guarantee you pick up more HP accross the powerband, and the more boost you are running, the more HP there is to unleash.
Think about hardcore V8 drag racers with N/A engines who run open headers at the track to pick up power. Boosted engines react differently than naturally aspirated in terms of Intake manifold pressure and exhasust manifold pressure relation and will benefit even more!! It's really a matter of "how much" rather than "if" you will pick up power.
My brother's 300ZX picked up almost 50whp by pulling off his old 2.5" dual muffler-less exhaust. He will be running the Boost Cutout this season as will I on my Supra.
Reid
Think about hardcore V8 drag racers with N/A engines who run open headers at the track to pick up power. Boosted engines react differently than naturally aspirated in terms of Intake manifold pressure and exhasust manifold pressure relation and will benefit even more!! It's really a matter of "how much" rather than "if" you will pick up power.
My brother's 300ZX picked up almost 50whp by pulling off his old 2.5" dual muffler-less exhaust. He will be running the Boost Cutout this season as will I on my Supra.
Reid
Last edited by Reid@SP; Feb 8, 2010 at 01:40 PM. Reason: typo
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From: Chicago
as a reference
When we did my motor break in we did it with the Stock exhaust on (y-pipe, mid-pipe, and muffler)......when they were building the exhaust larry did some pulls with just the open downpipes (3in).....
I have the AEM tru boost boost controller. So you set it to a % of duty cycle, not to a specific boost number.
With the stock exhaust on, at the setting the AEM was at, it made 11psi of boost.....removing the exhaust and doing a pull, it made 24psi of boost before larry let-off quickly!!!!!!!!!!! (and it hadn't hit full boost yet lol).
Now yes that is the 2 most extreme situations, but back-pressure and FI is bad, you want to get the exhaust away from the turbos as easy/fast of possible.
Tom
When we did my motor break in we did it with the Stock exhaust on (y-pipe, mid-pipe, and muffler)......when they were building the exhaust larry did some pulls with just the open downpipes (3in).....
I have the AEM tru boost boost controller. So you set it to a % of duty cycle, not to a specific boost number.
With the stock exhaust on, at the setting the AEM was at, it made 11psi of boost.....removing the exhaust and doing a pull, it made 24psi of boost before larry let-off quickly!!!!!!!!!!! (and it hadn't hit full boost yet lol).
Now yes that is the 2 most extreme situations, but back-pressure and FI is bad, you want to get the exhaust away from the turbos as easy/fast of possible.
Tom
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From: Bloomingdale, IL
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Joined: Feb 2010
Posts: 148
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From: Dekalb, IL
Actually Reid, we use 5 psi actuators on the exhaust valves. They begin to open at 5 psi and are fully open by 11. This is the lowest psi actuator that any one makes!! By about 7 psi they are halfway open which would relieve a ton of backpressure on a car only running 7 psi!
Easy answer is yes they will definitely help you out!!
Call my cell, PM me, or email me for more information or price quotes!!
Reid
(847) 363-3139
ReidatSP@aol.com
I am interested in this product, moveover how it performs on a supercharged car. How is the exhaust valve set to open at a certain boost level? (Sorry for the simplistic question)
What are your predictions for a supercharged G35 currently running 9lbs, with your exhaust product what do you believe to be the significance of the rwhp gains?
What are your predictions for a supercharged G35 currently running 9lbs, with your exhaust product what do you believe to be the significance of the rwhp gains?
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Joined: Feb 2010
Posts: 148
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From: Dekalb, IL
It is based purely on the boost applied. These actuators start opening at 5.5psi and are fully open at 11psi. So with 9psi you will have it almost fully open relieving a lot of pressure!!
Reid
Reid
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Joined: Feb 2010
Posts: 148
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From: Dekalb, IL
I just wanted to let you guys know I haven't forgotten that I promised data and dyno graphs! The car I was going to use to provide the info popped it's turbo. It has been replaced and is being put back on now. I should have some news soon!!
Reid
Reid
