upgrade fuel pump for nytro s/c

[extreman1]

Any body have the fuel pump upgrade for the nytro with s/c and did it fix the fuel flow problem? I was told the stock injectors are good for 14lbs boost is this true?? Last year i was told i would have to change injectors if i went higher then 8-10 lbs boost at sea level. its a mpi charger by the way Thanks

 

[rj998]

Ask Dave at hurricane, email him

 

[SWENytro]

Any body have the fuel pump upgrade for the nytro with s/c and did it fix the fuel flow problem? I was told the stock injectors are good for 14lbs boost is this true?? Last year i was told i would have to change injectors if i went higher then 8-10 lbs boost at sea level. its a mpi charger by the way Thanks

Any news? Do we need a upgrade @ sea level?

 

[pro116]

I have the upgraded fuel pump but never ran without it and i have the stock injectors.

 

[bottlerocket]

6-7lbs for stock injectors right?

 

[mbarryracing]

6-7 lbs for stock fuel pump and no regulator...

 

[procross]

what do you mean no regulator? there is a factory one.

didn't mpi offer a different regulator 1:1 at one point? what kind of boost can you run with just the 1;1 regulator?

 

[mbarryracing]

A Nytro doesn't have a return fuel line so the fuel dumps back at the in-tank fuel pump, via a built in pop-off valve that you could technically call a regulator. However, it doesn't "regulate" the fuel pressure to compensate for engine load like the vacuum referenced regulators on the fuel rails do. The fuel pressure stays constant. I agree, I also remember MPI offered a fuel system upgrade that consisted of a new regulator and a return fuel line adapter but can't recall if that included a new or additional fuel pump.

I don't think it's the fuel pressure so much as volume capacity shortcoming of the stock fuel pump. As the fuel consumption goes up with boosting, the pump can't keep up and therefore pressure drops even more. Volume and pressure are two different things.
Reason why for most stage 2 turbo kits for most sleds you have to run a supplimental high pressure fuel pump inline after the factory pump, even on an Apex with a factory 1:1 FPR.

I am not sure what the stock Nytro injectors will flow up to for HP if you were using a 1:1 FPR, but I've had my stock injectors on my Apex (with factory 1:1) over 22 lbs boost before the AFR starts to drift lean because they can't supply enough fuel (pegged at 100% duty cycle)...

 

[tjc]

the ulmer site has 8 psi on stock motor with fuel pump and regulator using pump fuel on the stage 2 at sea level. I think he pulls timing though. Then its 14 PSI on race fuel same setup. You might want to double check this because this is only what I read.

Keep in mind the Nytro has 330 cc injectors and the Apex has 390 cc.

http://www.ulmerracing.com/TCFX.htm

 

[Srxspec]

When doing a fuel system upgrade on the FX Nytro you must remove the stock pump and put a new pum pon or add a new inline fuel pump and also the pressure regulator. I have tried shimming the "regulator" in the stock pump up and with a small fuel psi increase then the pump can not keep up with enough volume to maintain pressure.

MPI's kit includes a new fuel pump and pressure regulator that is 1:1 rising rate.

 

[pro116]

When doing a fuel system upgrade on the FX Nytro you must remove the stock pump and put a new pum pon or add a new inline fuel pump and also the pressure regulator. I have tried shimming the "regulator" in the stock pump up and with a small fuel psi increase then the pump can not keep up with enough volume to maintain pressure.

MPI's kit includes a new fuel pump and pressure regulator that is 1:1 rising rate.

Thats the kit I got.

 

[Agman 57]

I also have the upgraded pump, took the stock pump out. Have run 12# with stock injectors with no problems. That was at 800 feet but only for short periods of time on pump gas. Normal run 6-8# for trail riding on pump gas

 

[extreman1]

thanks for all the replys very helpful, one more question, i have the magna force clutch arms from D&D, any idea on starting point with the magnets? I will be at 13-14 lbs boost at sealevel.