Is a fuel pump upgrade needed?
Oct 26, 2013 | 02:52 PM
#11
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From: Jennings LA
Just because some one is running 500hp on flex fuel pumps doesn't mean its the right way. The opposite is true about fuel pumps as well. With a 340lph pump the stock injectors will work to a higher horsepower. This is the same argument as with stock casting heads. Just, because it works doesn't mean its right.
Oct 26, 2013 | 05:17 PM
#13
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From: Jennings LA
OP, if you would. Specify what size shot your spraying and what future mods you referenced.
Gamble, yes that's common knowledge. I'm asking why it's not the correct way for the guys running 500+ rwhp with NO issues? The flex pump is a safe reliable upgrade.
Gamble, yes that's common knowledge. I'm asking why it's not the correct way for the guys running 500+ rwhp with NO issues? The flex pump is a safe reliable upgrade.
Oct 26, 2013 | 05:44 PM
#14
Ever seen the IDC's or fuel pressure readings at wot on those 500+HP builds using a stock flex fuel pump? Also I would like you to give actual individuals who have done it with "no issues", because I can't think of any. I am sure it has happened I just don't know who you are talking about.
"intake, LT headers, ported and polished factory heads, cam, 2800 stall"
I would guess he is about 375+ to the wheels. Add the spray he will be around 500rwhp.
"intake, LT headers, ported and polished factory heads, cam, 2800 stall"
I would guess he is about 375+ to the wheels. Add the spray he will be around 500rwhp.
Last edited by gamble686; Oct 26, 2013 at 06:00 PM.
Oct 26, 2013 | 09:03 PM
#15
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From: Jennings LA
Byrdman11
Goneb4u
Ak2007r6
Just to name a few in one thread, IDC's or even mentioned...
https://www.performancetrucks.net/fo...506082/page15/
Goneb4u
Ak2007r6
Just to name a few in one thread, IDC's or even mentioned...
https://www.performancetrucks.net/fo...506082/page15/
Oct 29, 2013 | 12:53 PM
#16
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It seems that some math is required. You may want to take a look to this mobile app: for iPhone or for Android, it has a lot of sections to calculate injector flow, pump flow even for engines running E85 and boost among other cool stuff.
Hope this helps!
Hope this helps!
Oct 29, 2013 | 07:06 PM
#17
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right now im only spraying 125 but if I were to ever get the internals built I would really turn it up. im looking at the walbro 255 and 340 lph but am having a bit of trouble finding one that says it will fit a 2007 Silverado 5.3. also do you have any experience with injectors that might work well with this?
Oct 29, 2013 | 07:13 PM
#19
A flex fuel pump is about 200lph and will run about $90 vs walbro is about 255lph $100 vs 340lph pumps $150. Pick your budget based on how far you want to take it. I disagree about the flex fuel being good to 550-600hp. The only way it is lasting that far is if you get big injectors. The ceiling on any fuel component is based on other parts of the fuel system. As for injectors stock injectors are about 24lbs/hr. I would suggest 36lbs as a good budget injector.
The 255 is usually fine but the larger. 340 400 and 450s would prop be trouble From what I understand .
Oct 29, 2013 | 08:42 PM
#20
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From: Jennings LA
right now im only spraying 125 but if I were to ever get the internals built I would really turn it up. im looking at the walbro 255 and 340 lph but am having a bit of trouble finding one that says it will fit a 2007 Silverado 5.3. also do you have any experience with injectors that might work well with this?
