Tell me if I have this right...pump saver question

Discussion in 'PSI Superchargers Tech Questions' started by Scouder, Jan 29, 2011.

  1. Scouder

    Scouder New Member

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    I was just sitting here trying to decide exactly what pressure to have my pump saver crack at. I'm guessing a little bit because I will be spinning the engine just a little bit faster this year than last year, so the peak pressure the system will see is an educated guess. That is what brought me to my question.

    If I get it wrong, and the pump saver cracks during the run, what happens?

    Since the pump saver is on the pump side of the barrel valve, and has no pill, it should just go rich at that point. Am I on the right track?

    -Brian
     
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  2. Blownalky

    Blownalky Top Sportsman

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    Brian,

    As explained to me from Jim at Enderle, the pump saver is not open or avaiable to pressure until the throttle is almost all the way closed. So, based on that , higher pressure when the throttle is open will not affect it. Somebody chime in if this isn't the case.

    Tom
     
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  3. orsoweld

    orsoweld New Member

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    where are you dumping the pump saver to???????????
     
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  4. pat Iley

    pat Iley Member

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    I was advised to have pump saver being returned to the hat distribution block to help keep the blower rotors cool as the pump saver comes into use at the end of a run where your blower was running at top speed and this will prolong strips and blower, also motor will be a little rich which won't hurt it
     
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  5. Mike Canter

    Mike Canter Top Dragster
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    Well, I have heard this many times before that the pump saver will not dump if the throttle is wide open. I say that is wrong. There is no oring seal inside the barrel valve to stop the alcohol from flowing out if that poppet cracks open. I watched it happen on a car. We had a manifold temp sensor and as the car went down the track the manifold temps kept on spiking down from 120* to 30* at the same time the fuel pressure would abruptly level off. I found the pump saver was set at the same pressure that the fuel pressure was leveling off. The fuel was dumping through the pump saver poppet into the blower and dropping the temps abrupty down.
     
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  6. Blownalky

    Blownalky Top Sportsman

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    Well, there you go. I had the "Text Book" answer and Mike comes back with the "Real World" answer. I just went through this and now I have three different pump savers set at 150, 175 and 200LBS. I'll be testing this out to see what they show on the computer. Mike, as always, thanks for your "spot on" advice.

    Tom
     
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  7. pat Iley

    pat Iley Member

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    I can see where that is possible however if a system is set up proper you set the poppet at a higher set value than your running fuel pump pressure it will open up when the throttle shuts down and fuel pump is still turning at high speed due to motor rpm it builds higher pressure at barrel valve and pump saver should open. I guess that if you are going to plump system like this you should have good information with regards to fuel pump pressure and fuel flow to monitor system is correct. the key to getting a fuel system correct is with data from a proper set up system which some people cannot afford or sending your system to a fuel injection geru with your motor specs. both cost money but can save you in repairs if your fuel system has problems
     
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  8. Scouder

    Scouder New Member

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    Sorry about not including all the info. Yes, I am dumping back to the hat.

    So what I'm getting here is that all it does is go rich if it cracks at full throttle?

    I only need one run to see where the fuel pressure peaks, then I can set the poppet where I want it. I just wanted to make sure it wasn't gonna hurt anything if it was too light on that run.

    -Brian
     
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  9. pat Iley

    pat Iley Member

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    some racers also use this poppet as a fuel volume control as the pump makes to much volume at part throttle and at launch if they leave at 3000 to 5000 rpms the pistons go cold hurting performance in this case you must return fuel to fuel tank. the position of the spool must be correct as it is designed to work at part throttle and closed throttle.
     
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  10. orsoweld

    orsoweld New Member

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    that's what I also do.
     
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  11. orsoweld

    orsoweld New Member

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    I think your right, I also thought it only works when you close the throttle ,but I notice that my fuel pressure Max's out right around the pressure of my pump saver, I noticed it when I tried running more rpm, I was turning the motor around 8000 everything looks OK, I went to 9000 the car slowed down and the rpm and fuel pressure goes crazy, I dump into the hat from the pump saver,I think it is getting to fat???? because the pump saver is opening??????? or I am crazy or doing something wrong???????
     
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  12. orsoweld

    orsoweld New Member

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    pressure

    may I ask what kind of pressure you guys are setting you pump savers at???????????
     
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  13. pat Iley

    pat Iley Member

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    the spool that is in the barrel valve will allow this poppet to work at part throttle and when closed also. when setting this up you need to know fuel pressure at barrel valve at operating rpm. fuel pressure will be affected by so many varibles such as fuel line size, injector nozzle jets and motor rpm if you go from 8000 to 9000 rpm you spin fuel pump faster more pressure occurs . if you had a jetsize program from Davenport it helps you by calculating fuel pressure changes with the changes you do with regards to your system. if not you just go from your data recorder. if your motor is losing power at 9000 rpm you may need to lean fuel and or adjust timing, what class are you running in.These fuels systems are complex and is hard to say what works for one persons setup will work with yours. it helps to understand the basics of them and then work on yours to get your system right without hurting parts. However what ever changes you do to in small steps and don't do a full pass unless you are sure you won't hurt your motor. there is a good post from Mike Canter on reading spark plugs which will be of great information to assist you. I have used the book from lowes fuel injection and have dealt with fuel injection enterprises both have been very helpful .
     
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  14. Alkydrag

    Alkydrag Sr. Dragster

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    With the fuel system set up "properly", the pump saver does the job it's supposed to do. It should only open when the throttle is closed and the pump is at high RPM. This keeps the pump from blowing up. The crack pressure should be about 50 psi above peak pressure. If it's opening up during the run, then the pressure is set too low.
     
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  15. Reeves Racing

    Reeves Racing New Member

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    Pump it

    Yeah, What he said
     
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  16. Blownalky

    Blownalky Top Sportsman

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    My system has been flowed and it came back at 155LBS @ 8k and 173 @ 9k and that is why I had the different valves so I can check it out. Probably will end up with the 200LB valve. Just got the Davenport program yesterday in the mail. Will be installing it today to check it out.

    I have a single -10 line out of the barrel and am going to plumb the pump saver back to the port outlet of the barrel valve. Anybody see any issues with this?
     
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  17. pat Iley

    pat Iley Member

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    Do you have port and hat nozzles and using one line with a flow meter. I would run the pump saver to the hat distribution block.returning it to the barrel valve you will have the pump pressure going against your line. as you are doing your run the port line will be trying to force fuel down your return line and what ever pressure you have will be forced against the poppet maybe causing a failure and damaging barrel valve. also when you shut throttle off the pressure will be still there. the fuel in the line will not go to motor as spool in barrel valve will not allow this, and you are putting fuel back into where you want to take it away
     
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    Last edited: Jan 30, 2011
  18. Mike Canter

    Mike Canter Top Dragster
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    You have to be careful on setting the Pump Saver Poppet because the fuel pressure increases as you change the tuneup to compensate for lower Density Altitudes. Sometimes this can change the fuel pressure by over 50 psi unless you change out hat and blower nozzle jets. So setting the Pump Saver at 50 psi above your max fuel pressure at 3500 ft DA may get you into trouble if the DA changes to 500 ft. If you have Jetsize then you can play "what if" and find out what your max fuel pressure can be and set the poppet above that pressure. I find that if I set mine always in the 200-220 psi range I never have a problem.
     
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  19. aj481x

    aj481x Member

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    Another thought on "pump savers", plug it and forget about it. ;)
     
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  20. SoDak

    SoDak Active Member

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    I have never tried it but yes I would think this would work.
     
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