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aka Nova Joe
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I put a pump on my car (Mr. Gasket Sportsman) and I'm scratching my head a little. I got the Aerospace regulator in my valve cover, and was just wondering which way builds more vacuum, threading it in or out? It didn't come with any instructions or anything. I got 3" at idle, 8" at ~2500rpm cruising, but I still only have 8" at WOT...When I cross the finishline as soon as I take my foot off the throttle it jumps up to 11"/12" then goes back down:confused: ...Never had a pump before, so I'm not sure..But I would think it would pull more at WOT and go down when I let off...no?
 

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Did you check the system for leaks? You want about 4"-5" at idle, depending on how high the idle is, and about 13" through the traps. I sue the Moroso regulator with shims, but if you just screw it in or out, and just bring rpm's up to 3k, you will notice a difference and see which way it needs to be adjusted, and aim for that 13". Anymore and it will start pulling oil pressure down and start hurting things.. Set up a fitting off the gauge line with a valve and hook up air to it and just open it slightly, not needing 125psi of air line, and see if you have any leaks anywhere. System needs to be completely sealed. Once it is sealed, you should start seeing vacuum. With those regulators, I think by turning it out allows it to pull more vacuum..but do it and check.
 

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EFI/N2O JUNKIE
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I would think the reason you see more vacuum when you lift is because now the rings aren't fighting to seal-off combustion pressure and the pump can pull a better vacuum. A few years ago I shot the car with a .082N jet (had a good tune with the .063N jet). Well, that didn't go too well! As soon as I launched and came-down from the wheelstand I saw the vacuum gauge bouncing up and down so I killed the nitrous and kept my foot to the floor. As soon as I killed the juice the vac shot to 12" and was steady as a rock. Found oil in the breather/seperator tank after that pass. Put the .063N jet in it, made a pass HOURS LATER (yeah, closing day at E-Town, you know what that is like!) and the car was perfect.

That taught me a few things: #1, don't jump jet sizes so quickly! #2, watch the vac guage (I also data log it) and if it is bouncing or doing something different find out why!
 

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You would have to kill the rings pretty bad to lose vacuum. What happens if you bring the rpm to say 4k? Will vacuum increase over that 8" it stops making at 2500? Point is, check it when it is not under a load as opposed to under a load and it will tell you if it is the rings..
 

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I put a pump on my car (Mr. Gasket Sportsman) and I'm scratching my head a little. I got the Aerospace regulator in my valve cover, and was just wondering which way builds more vacuum, threading it in or out? It didn't come with any instructions or anything. I got 3" at idle, 8" at ~2500rpm cruising, but I still only have 8" at WOT...When I cross the finishline as soon as I take my foot off the throttle it jumps up to 11"/12" then goes back down:confused: ...Never had a pump before, so I'm not sure..But I would think it would pull more at WOT and go down when I let off...no?
A vacuum regulator works by introducing a controlled leak into the system. This keeps the vacuum from climbing as pump speed increases.
A momentary spike in vacuum is common when first lifting the throttle. The reason is simple: practically all the blow-bye stops instantly when lifting, however the vac pump speed (and its out put) is still high due to the high RPM the pump is turning until the engine RPM drifts down. When we look at vacuum graphs from data recorders we see this all the time.
I suggest you remove the regulator from the valve cover and place it out side the crankcase area, preferably directly on the pump. When a regulator located in a valve cover reaches the set point, it creates a path of air through the engine to the vac pump. Although this location will limit the vacuum potential, this subsequent path of air will promote scavenging oil (windage) into the vacuum pump. Unfiltered air will be drawn into the engine, heated, and then it will flow through the vac pump. By positioning the regulator directly on the pump, the leak is taken out of the crankcase area where no oil can be siphoned. Cooler, filtered, ambient air now flows directly through the vac pump only.

Star Hg
 

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EFI/N2O JUNKIE
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That is one thing I need to change on my engine this year. If this is Steve from Star ^^^ do you have something that will go in-line with your clear hoses that I can stick in there? I have a Moroso regulator screwed into my oil fill cap so I can easily take that one out of there. You guys were away at a race when I found I needed one when I finally got your system installed and running so I got a Moroso reg locally.
 

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That is one thing I need to change on my engine this year. If this is Steve from Star ^^^ do you have something that will go in-line with your clear hoses that I can stick in there? I have a Moroso regulator screwed into my oil fill cap so I can easily take that one out of there. You guys were away at a race when I found I needed one when I finally got your system installed and running so I got a Moroso reg locally.
Mike, just me a call and I can suggest the best way to do it based on what you may allready have.
Steve
 

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I put a pump on my car (Mr. Gasket Sportsman) and I'm scratching my head a little. I got the Aerospace regulator in my valve cover, and was just wondering which way builds more vacuum, threading it in or out? It didn't come with any instructions or anything. I got 3" at idle, 8" at ~2500rpm cruising, but I still only have 8" at WOT...When I cross the finishline as soon as I take my foot off the throttle it jumps up to 11"/12" then goes back down:confused: ...Never had a pump before, so I'm not sure..But I would think it would pull more at WOT and go down when I let off...no?
nothing to get excited about, all normal stuff.. When the engine drops back after the run, the pump is still spinning making vacuum, but the engine is not making any pressure in the cylinders, so the vacuum jumps up..
 
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