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Discussion Starter · #1 ·
I think most agree the stock system will support 600 to 615 flywheel hp comfortably. After that it is time to upgrade to provide a reliable source for the increased demand. I am mainly interested in working from the pump forward and understanding what is needed to create more volume.


If one replaces to pump, but not the lines leading to the motor, is a significant increase in volume goona occur? It seems the lines would continue to be a bottleneck to the flow of fuel to the motor. I assume with the increase in pressure and increase is volume is goona occur to some degree, but how effective is it really?


I really don't want to do fuel rails, but will a pump be suffecient without changing to a bigger diameter line going to the motor? But then one gets to the injectors and they can only flow so much........so soes it do any good changing pumps without going to a bigger injector?


What kind of volume increase is seen just by swapping pumps with stock injectors? Not much I would assume.


John
 

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you gotta increase the line dia if your going to go with a bigger pump or your car will develop hypertension. i doubt that more volume could in fact be pushed if the diameter of the lines are not increased to correlate with the larger pump to match its output. injectors increased as well. all or none principle. anatomy and physiology on a car eh /images/graemlins/toothy
 

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Several people have made 650-675 rwhp by using a boost a pump and increasing voltage to the stock pump, sometimes in combination with another in-line pump. Above that you're probably better off to replace everything.
 

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AB on the other board is completely re-doing his fuel system. Might want to PM him for clues. I may do something similar in the future. :thumb: :thumb:
 

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Hey Jdawg..

You will need to go with larger line. I am using -10 AN hose which is probobly and over kill, but if you use the stock lines, you will cause your fuel pump (if you are getting a higher flow pump) to over heat...the stock stuff will not be able to handle the flow of increase fuel. Also you could go with larger side fed injectors by having your stock injectors opened up...but the problem there is the stock internal fuel rails in the plenum is not going to flow enough fuel plus with more volume you will need to do a return fuel line system.

I just redone my entire fuel system and it's ready to flow!
 

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silvergts1998 said:
Hey Jdawg..

You will need to go with larger line. I am using -10 AN hose which is probobly and over kill, but if you use the stock lines, you will cause your fuel pump (if you are getting a higher flow pump) to over heat...the stock stuff will not be able to handle the flow of increase fuel. Also you could go with larger side fed injectors by having your stock injectors opened up...but the problem there is the stock internal fuel rails in the plenum is not going to flow enough fuel plus with more volume you will need to do a return fuel line system.

I just redone my entire fuel system and it's ready to flow!
John, I agree with Adam. Just re-do the whole thing with bigger pump, lines and return fuel system.

I think you should add a turbo or two while you are at it! /images/graemlins/laughing.gif :thumb:
 

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Discussion Starter · #7 ·
I was wondering about the lines going to the intake if they would be large enough to see any gains from a better pump. So I am assuming the stock line is probably around a -4???


I would like to stay with sidefed and I think I could either get them enlarged or I believe someone sells a 36 or 37 lb sidefed. Appreciate the feedback. It probably isn't that big of a task to do the system I would just like to do it right the 1st time.



John
 

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J DAWG said:
I was wondering about the lines going to the intake if they would be large enough to see any gains from a better pump. So I am assuming the stock line is probably around a -4???


I would like to stay with sidefed and I think I could either get them enlarged or I believe someone sells a 36 or 37 lb sidefed. Appreciate the feedback. It probably isn't that big of a task to do the system I would just like to do it right the 1st time.



John
John, to do it right the first time would be to go to the -10 line splitting into (2) -8 lines with fuel rails with maybe a smaller(than the big aeromotive) pump and just have a voltage regulator slow the pump down, That way you do not have to do everything twice when you go to the next level of power.

I think the stock fuel line might be even less than a -4.

Besides enlerging the stock injectors is something like $1500.00 form RC engineering. It would be cheaper to buy a set of fuel rails and the smaller initial set of injectors than to try to make yours flow more.

I remember our conversation of about a week ago in regards to your datalogging the initial leanness of the AF as the nitrous is coming on, I think you need to think about the big picture and only dick with that stuff once. Going with a bigger external pump with a voltage regulator with the proper volume lines is your best bet. :thumb:
 

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The 1st thing to consider is how much power you want. The more power, the more fuel. A system that will flow enough fuel for 2500rwhp is nothing like a system for 850rwhp. Pumps, lines, injectors, fuel rails and filtering system none of it is the same. For 650rwhp you can just about get away with nothing but voltage booster.

I don't know your system or what mods you have to the car already. Looking in your gallery you have cats and roller rockers. I'm sure you have more then that though.

What's your target rwhp?
 

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Tanked said:
The 1st thing to consider is how much power you want. The more power, the more fuel. A system that will flow enough fuel for 2500rwhp is nothing like a system for 850rwhp. Pumps, lines, injectors, fuel rails and filtering system none of it is the same. For 650rwhp you can just about get away with nothing but voltage booster.

I don't know your system or what mods you have to the car already. Looking in your gallery you have cats and roller rockers. I'm sure you have more then that though.

What's your target rwhp?
Why dont you take the in-tank stock mopar fuel pump out and reinstall one from a F-14 in your car. Then to be consistent with your other nonsense, come back and tell us how your viper is going to make 300000 pounds of thrust, make barrel rolls, fire missiles, and can take off from an arcraft carrier?
 

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I have the complete Paxtom kit fuel system for sale and 10 larger injectors,(the Roe injectors that he includes with his kit), you will need fuel rails for these blue top fed injectors. Make me an offer, pics avail, or $200 for just the injectors. I ended up going with RC 54 lb injectors , but they are not cheap.
 

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Top feeds are the way to go. -10 AN lines and new fuel rails. SX APFR works very well, so does aeromotive stuff. 550cc injectors are 46lbs/[email protected]% (or 52lbs/hr at full cycle) and are redily available. RC uses PTE injectors, which are what I use. You can pick them up fairly cheep from ebay, ~350 for a set of 6, and find another set of 4 and you're set.

As for pump, you can use an inline. Not like you're going to hear the buzzing anyway /images/graemlins/laughing.gif
 

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JDawg:

A SC car (must overcome boost) and a N2O have different fuel pump demands. I believe that Albert did his 150 MPH run with a modified N2O engine with only the 255 liter WALBRO. On A modded N2O car the Walbro and boost-a-pump should be sufficient. It is so simple, log the the fuel pressure as you bring up the shot. That is so much simpler than doing a modified fuel system. If the logging proves the pump ample, put the money elsewhere
 

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Discussion Starter · #15 ·
Jack, what pressure gauges have the logging capability?



Fuel rails would be nice, but I am not in the mood to tackle that right now..........maybe soon though. It doesn't appear to be difficult, just maybe some fitament problems that would have to be overcomed UNLESS someone makes a set of rails that fit perfectly on a viper. Anyone???
 

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Discussion Starter · #16 ·
ps - is it necessary to go with an external pump with fuel rails? I know most that are pushing huge hp do or use a dual intank setup, but is an upgraded single intank with fuel rails good for <750 rwhp?
 

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JDawg:

The new electric version of all Autometer gauges are built for logging. They give you a 0-4.5 volt out. I run the Innovate logger like yourself and it picks up the fuel pressure perfectly. The new Innovate software can be configured to display the fuel presssure in psi in lieu of the voltage.

The fuel rails by them self do not automatically necesitate a different pump, the engine has to ask for more fuel. The only reason for adding fuel rails is when the side feed injectors go static due to the engine demanding more fuel than they can supply.
 

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J DAWG said:
Jack, what pressure gauges have the logging capability?



Fuel rails would be nice, but I am not in the mood to tackle that right now..........maybe soon though. It doesn't appear to be difficult, just maybe some fitament problems that would have to be overcomed UNLESS someone makes a set of rails that fit perfectly on a viper. Anyone???
West coast Viper has them.
 

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Discussion Starter · #19 ·
Those look like some nice rails.


What is the parts list for the rail system?

I see 40 lb injectors everywhere and I am getting a pump, so other than those things and some line is that about it?
 
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