TRIPPLE FUEL PUMP PICK UP
- Thread starter silvergt8
- Start date
Have to do a surge tank set up. I've got the whole fuel system in stock i believe. You DO not want to be modifying inside your gas tank. its expensive
MarkH
GT Owner
Agree with Dan, not worth messing with the stock fuel tank. To easy just to add the Radium surge tanks and get it all plumed correctly. We have done many of these setups on customers cars making lots of power. I can tell you, we have seen several cars come in with blown motors that have not had additional fuel measures taken when they have been modified. In, our opinion the stock fuel system is only able to handle so much and pushing the limits can be costly.
Mark Heidaker
M2K Motorsports
281-346-8114 office
Mark Heidaker
M2K Motorsports
281-346-8114 office
2112
Blue/white 06'
Mark,
What power level would you say is the limit for the stock fuel delivery unit?
How much more if you use install a boost a pump?
Thank you
What power level would you say is the limit for the stock fuel delivery unit?
How much more if you use install a boost a pump?
Thank you
Depends whether blower or turbo. A turbo GT can make more rwhp safely with the factory pumps than a blower car can due to the fuel loss you don't see at the rear wheels that it takes to turn the supercharger. The GT only has twin 300lph pumps. Boost a pumps help but when two pumps are tied together you get only about 75% out of the two combined for lph.
2112
Blue/white 06'
OK, Makes sense.
So what would you say the upper limit for a blown motor is with stock pumps and no auxiliary tanks?
So what would you say the upper limit for a blown motor is with stock pumps and no auxiliary tanks?
BlackICE
GT Owner
I don't know if you jack up the the pressure of the stock fuel pumps. However with the stock pressures on the fuel rails I was running over 85% on fuel pump and over 90% injector duty cycle using an 21 PSI pulley on a gen 1 Whipple at Mojave. And even at that it was running towards the lean side so I stopped after my past my goal of 200 miles an hour. Mohave is at high altitude so the true boost is less than 21 PSI.
2112
Blue/white 06'
:thumbsup Thanks guys, I am only on a 3.4L Whipple and around 700 RWHP. Safe for a while at least.
MarkH
GT Owner
We see a lot of GT’s that are modified and many are not even having the boost a pump. The problem we see more often than not is the cars making 900rwhp and they run for a while like everything is great. Over time I believe the pumps as well as injectors and the fuel control module start to see some wear and tear and next thing you know is that nice oil smoke out the exhaust and it’s to late. For sure these cars will make a lot of power on less fuel mods but some are on edge and the repair can become timely and costly. I still say there is never enough power and what a great car to mod but make sure your over build for the power you desire.
Mark Heidaker
Mark Heidaker
Yes you have to modify your fuel filler neck for a return line and the system is no longer a dead head system. You have to do a return style fuel system, NO if ands or butts about it. I make 1500whp on e85 with my 3 gallon surge tank, I put larger pumps in factory tank to feed it, then pull fuel out of it to aftermarket pump, returning fuel in to it from regulator and then when surge tank is full it returns back to the filler neck. 3 gallons will give you plenty of distance for a pull and combine that with still free flowing fuel in from gas tank you will have plenty of fuel even on e85 if you choose to run that.
Indy GT
Yea, I got one...too
A 3 gallon surge tank providing the main draw for the engine at Wide Open Throttle (WOT) sounds about right for a gasoline powered 1,500 hp engine.
Assume 10% max horsepower = fuel flow rate at WOT = 150 gal/hr (Pretty good rule of thumb)
Assume IC engine thermal efficiency (work output/energy input) = 22%
Gasoline energy input necessary to produce power = (1500/0.22)*(42.44 BTU/min*hp) = 289,364 BTU/min
Assume energy content of gasoline = 19,065 BTU/lb and 1gal fuel = 6 lb
(289,364)/(19,065*6) = 2.53 gal/min fuel flow necessary with gasoline
However, since alcohol is significantly inferior to gasoline in energy content, you need to supply about 70% more fuel to the engine for the same 1,500 hp output.
Assume energy content of methanol 9,770 BTU/lb and 1 gal methanol weighs 6.87 lb
(289,364)/(9,770*6.87) = 4.31 gal/min fuel flow necessary with methanol
(289,364)/12,780*6.81) = 3.32 gal/min fuel flow necessary with ethanol (little bit better)
Assume 10% max horsepower = fuel flow rate at WOT = 150 gal/hr (Pretty good rule of thumb)
Assume IC engine thermal efficiency (work output/energy input) = 22%
Gasoline energy input necessary to produce power = (1500/0.22)*(42.44 BTU/min*hp) = 289,364 BTU/min
Assume energy content of gasoline = 19,065 BTU/lb and 1gal fuel = 6 lb
(289,364)/(19,065*6) = 2.53 gal/min fuel flow necessary with gasoline
However, since alcohol is significantly inferior to gasoline in energy content, you need to supply about 70% more fuel to the engine for the same 1,500 hp output.
Assume energy content of methanol 9,770 BTU/lb and 1 gal methanol weighs 6.87 lb
(289,364)/(9,770*6.87) = 4.31 gal/min fuel flow necessary with methanol
(289,364)/12,780*6.81) = 3.32 gal/min fuel flow necessary with ethanol (little bit better)
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Thankfully a gt on ethanol E85 (NOT alcohol/Methanol) 30% more fuel is required over gas and WOT time 22-25 second for lets say a mile run. With 680lph pumps in the oem tank free flowing into that 3 gallon surge tank one should still have more than enough fuel to complete a mile run and I don't think anyone here would be looking to do anything over that.
TO AWSUM
Ford GT Owner
Indy GT
Yea, I got one...too
Again BMF that sounds about right too.
E85 (85% ethanol + 15% gasoline) is better than straight methanol or ethanol but not a whole lot better. The energy content of this fuel can also be easily calculated by looking at the fractions, thus-
((85/100)*(12,780)) + ((15/100)*(19,065)) = 13,723 BTU/lb
E85 is about +7.4% better energy density relative to straight ethanol but -28% lower energy density relative to straight gasoline.
Thus as BMF indicates above to develop the same horsepower with the E85 fuel, you need to supply +28% (about 30%) more fuel to the engine. This is why laypeople are always perplexed that their FlexFuel vehicle gas mileage "tanks" when they fill up with E85. The engine needs 30% more fuel to support the driver's gasoline performance levels.
Thanks Chip, it’s all in the math…….:biggrin