Boost loss from bypass valve? general questions
Thread Starter
Launching!
Joined: Feb 2008
Posts: 235
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Boost loss from bypass valve? general questions Hi guys. Since the lt section doesn't have section for power adders, I thought this might be where I'd get the best info.
Concerning boost loss, I have a 383 vortech ysi setup and am only seeing about 14-15lbs of boost. I am using a 7.35" crank, 2.75" blower and have only spun it up to 5000-5200 so far, but boost isn't climbing like it should. Belt wrap is excellent around the blower pulley with just under 270* or so of wrap. I realize that I'm not spinning it hard but I still think I should be getting more boost considering I'm using a small cam (hot cam).
My question is, if there is more pressure in the discharge tube than in the manifold, how big of a differential can there be before the procharger red bypass valve gets forced open? I'm running a dual 58mm throttle body so there is a restriction between the manifold and the discharge tube.
Are there any newer parts that can help fix this if it truly may be a problem? Other than that, I'm going to be tossing in fresh valve springs; the ones I have on the car are old and probably have gotten weak which I heard may also cause some boost loss and valvetrain float.
Any suggestions, ideas or even speculation is appreciated.
Concerning boost loss, I have a 383 vortech ysi setup and am only seeing about 14-15lbs of boost. I am using a 7.35" crank, 2.75" blower and have only spun it up to 5000-5200 so far, but boost isn't climbing like it should. Belt wrap is excellent around the blower pulley with just under 270* or so of wrap. I realize that I'm not spinning it hard but I still think I should be getting more boost considering I'm using a small cam (hot cam).
My question is, if there is more pressure in the discharge tube than in the manifold, how big of a differential can there be before the procharger red bypass valve gets forced open? I'm running a dual 58mm throttle body so there is a restriction between the manifold and the discharge tube.
Are there any newer parts that can help fix this if it truly may be a problem? Other than that, I'm going to be tossing in fresh valve springs; the ones I have on the car are old and probably have gotten weak which I heard may also cause some boost loss and valvetrain float.
Any suggestions, ideas or even speculation is appreciated.
Thread Starter
Launching!
Joined: Feb 2008
Posts: 235
Likes: 1
http://www.siliconeintakes.com/intak...ster-p-49.html
Pop off your charge pipe. Hook this guy up. Add 10lbs of air to it and listen. Up to 15lbs and listen. 20 lbs and listen etc...
At around 30lbs you can stop. If it's not leaking there I doubt your running more pressure than that.
Wherever air is escaping you have a boost leak. Fix it. :-)
Pop off your charge pipe. Hook this guy up. Add 10lbs of air to it and listen. Up to 15lbs and listen. 20 lbs and listen etc...
At around 30lbs you can stop. If it's not leaking there I doubt your running more pressure than that.
Wherever air is escaping you have a boost leak. Fix it. :-)
9 Second Club
Joined: Nov 2003
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From: Norn Iron
Hi guys. Since the lt section doesn't have section for power adders, I thought this might be where I'd get the best info.
Concerning boost loss, I have a 383 vortech ysi setup and am only seeing about 14-15lbs of boost. I am using a 7.35" crank, 2.75" blower and have only spun it up to 5000-5200 so far, but boost isn't climbing like it should. Belt wrap is excellent around the blower pulley with just under 270* or so of wrap. I realize that I'm not spinning it hard but I still think I should be getting more boost considering I'm using a small cam (hot cam).
My question is, if there is more pressure in the discharge tube than in the manifold, how big of a differential can there be before the procharger red bypass valve gets forced open? I'm running a dual 58mm throttle body so there is a restriction between the manifold and the discharge tube.
Are there any newer parts that can help fix this if it truly may be a problem? Other than that, I'm going to be tossing in fresh valve springs; the ones I have on the car are old and probably have gotten weak which I heard may also cause some boost loss and valvetrain float.
Any suggestions, ideas or even speculation is appreciated.
Concerning boost loss, I have a 383 vortech ysi setup and am only seeing about 14-15lbs of boost. I am using a 7.35" crank, 2.75" blower and have only spun it up to 5000-5200 so far, but boost isn't climbing like it should. Belt wrap is excellent around the blower pulley with just under 270* or so of wrap. I realize that I'm not spinning it hard but I still think I should be getting more boost considering I'm using a small cam (hot cam).
My question is, if there is more pressure in the discharge tube than in the manifold, how big of a differential can there be before the procharger red bypass valve gets forced open? I'm running a dual 58mm throttle body so there is a restriction between the manifold and the discharge tube.
Are there any newer parts that can help fix this if it truly may be a problem? Other than that, I'm going to be tossing in fresh valve springs; the ones I have on the car are old and probably have gotten weak which I heard may also cause some boost loss and valvetrain float.
Any suggestions, ideas or even speculation is appreciated.
Whether there is more pressure in the discharge tube really depends ho restrictive your plumbing and intercooler is. There could be none, or loads.
But your problem will be blower drive related, or simply that you're nowhere near spinning it hard enough. Although I'd think that with such low blower speeds, 14-15psi in the intake at only 5000rpm is a lot of boost !
