auto2665
Extreme
I am hoping to run my supercharger at 11-12 psi on a Nytro with a head shim. Is the stock fuel pump capable or is an upgrade needed to provide the correct amount of fuel? I was told I might need an upgrade. Also, what gearing can I use to get to these numbers?
MPI web site says you can run stock fuel pump up to 14psi. I just changed my pully combo from 28t/28b(7psi) to 26t/28b and was told this should be about 11psi.
PowderFalcon
Pinnin' it!
I'm running an MSD pump on 10lbs boost. Was advised that it will keep constant pressure as a cheap insurance measure. Have spent $100 on worse things!
kinger
VIP Member
Make sure to have a AF gauge and see if you can find some wide open space to watch it as you accelerate, if it gets leaner under WOT you need a pump. My stock Apex pump was 'supposed' to be ok for 10-11 psi and I had to get a 255LPH to feed the beast. your running as much power as me so what bmcfadded said is not a bad idea. If you have the AF gauge I would practice with it and make sure its holding your WOT AF you want then you don't need to worry and consider that you got a 'strong' factory pump.
auto2665
Extreme
My Gems is programmed for 7psi....if I jump to 10psi does the Gems need to be programmed as well or will it still be ok?
kinger
VIP Member
There is no programming based on boost it just manipulates the fuel signal. Just add more fuel. Start rich they seem to run strong even when very rich.
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auto2665
Extreme
where can the MSD pump be purchased and how does it plug into the existing system? Does it use the OEM connectors or does it need to be spliced somewhere? What controls the pump? How is this different than what Ulmer Racing or MPI sells?
YamerHammer
Expert
1. I bought mine off ebay. (I am running 10 lbs of boost and stock pump got weak after about 500 miles)
2. No it don't plug into OEM plug you have to wire it in with a relay and fuse.
3. You splice the relay in where old fuel pump is wired. (I took the stock pump right out and rigged up a hose where the old pump was to the filter that was fitted on the bottom of the pump so the filter just about hits the bottom of the tank. This is so fuel can be pulled from the bottom of the filter as well so don't set it on the bottom of the tank or you will get fuel restriction. I also used a piece of coat hanger to stiffen the hose so it doesn't bounce around and zipptied it to the hose.)
4. The stock system controls the pump. (Make sure you use a relay and fuse on the power side of the pump.)
5. It is not different at all but it might save you some money. (you are just looking for a 255 gph high presser inline fuel pump. Most people including myself use the MSD pump because they are easy to come by.)
My advice if you don't know how to do this you might not want to go anymore boost than what you have. 10+ lbs is a whole new ball game. The maintenance is alot of work plus before you start running more boost you have to start building the sled up abit first to take the extra power so you don't break something and to harness the extra juice. For example clutching, extrovert drivers, temp gauge, injectors(Nytro) and new chain is what I would do before pumping up the boost. I am not saying don't do it but I am telling you from experience, hold on to your wallet cause your maintenance bill will be double.
Anymore questions........ask there is no dumb questions and we might be able to save you some money in the long run.
Cheers
2. No it don't plug into OEM plug you have to wire it in with a relay and fuse.
3. You splice the relay in where old fuel pump is wired. (I took the stock pump right out and rigged up a hose where the old pump was to the filter that was fitted on the bottom of the pump so the filter just about hits the bottom of the tank. This is so fuel can be pulled from the bottom of the filter as well so don't set it on the bottom of the tank or you will get fuel restriction. I also used a piece of coat hanger to stiffen the hose so it doesn't bounce around and zipptied it to the hose.)
4. The stock system controls the pump. (Make sure you use a relay and fuse on the power side of the pump.)
5. It is not different at all but it might save you some money. (you are just looking for a 255 gph high presser inline fuel pump. Most people including myself use the MSD pump because they are easy to come by.)
My advice if you don't know how to do this you might not want to go anymore boost than what you have. 10+ lbs is a whole new ball game. The maintenance is alot of work plus before you start running more boost you have to start building the sled up abit first to take the extra power so you don't break something and to harness the extra juice. For example clutching, extrovert drivers, temp gauge, injectors(Nytro) and new chain is what I would do before pumping up the boost. I am not saying don't do it but I am telling you from experience, hold on to your wallet cause your maintenance bill will be double.
Anymore questions........ask there is no dumb questions and we might be able to save you some money in the long run.
Cheers
auto2665
Extreme
I just bought an Ulmer clutch kit and have the gauges. What is the capacity of the stock nytro injectors? Is it the fuel pump or the fuel injectors that are insufficient when the boost gets up there? I think I settled on 10psi so I was hoping the stock system was sufficient. Where would I look into getting an upgraded chain? Can anyone verify the pulley combo of 26t/28b getting 10 psi? Another thread I read said 25t/29b so these seem pretty different. This will be used in low elevation.
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On a Nytro model you need both a fuel pump and regulator, as there is no regulator built onto the stock fuel rail, it is part of the stock fuel pump assembly.
auto2665
Extreme
looking on Ulmer web site and don't see the fuel pump. Is there a link to the product you are speaking of?
YamerHammer
Expert
http://www.ebay.com/itm/MSD-2225-Hi...ash=item35f45e9073:g:MbEAAOSw5VFWLvpW&vxp=mtr
You can get fuel regulator off ebay as well but my advice is to buy a brand name one and not a knock off brand.
You can get fuel regulator off ebay as well but my advice is to buy a brand name one and not a knock off brand.
Big_Phil
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You will need bigger injectors to go past 200hp on a Nytro as well.
I will be running 8-10lbs of boost on a supercharged Nytro. If the stock fuel pump cannot provide the necessary fuel for that boost what symptoms will I experience? How will I know that the fuel pump is not keeping up? Will it be dangerous to the engine or will it just stop running smoothly when fuel runs short? I don't expect to hit peak boost often as the trails we ride in are generally pretty tight and only occasionally open it up for a stretch. The upgraded pump is too expensive to add this year. I made a rookie mistake by adding boost without knowing the consequences first. I'll be saving up for the stage 1 upgrade kit for next year.
Big_Phil
TY 4 Stroke Master
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Your motor will blow up if you run out of fuel essentially. You will get detonation, not good. Could be as simple as blowing a headgasket, or as bad as putting a rod thru the block. Depends how lean it is and how hard you are running it.
If you have an A/F ratio gauge, you will know if you are running lean or not. You need bigger injectors to run 10psi, and prob head studs too.
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