walbro vs t-rex... Interesting

moneypit94

Active Member
May 23, 2003
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Macomb, IL
I couldn't figure out why AFM suggested i get a t-rex to replace my walbro inline 255 lph when i started going uncontrollably lean at 5k rpms... Because t-rex is rated at 50 gph which is roughly 190 lph.

AFM had told me that the ratings on the fuel pumps can be missleading and that they will make the advertised specs but it may only be 2 inches from the fuel pump instead of at the end of the line.

But i still couldn't see how a 190 lph could be recommended over a 255 lph till now. The t-rex is rated 190 lph @ 70 psi and i did some searching and found that the wablro is rated at 255 @ 20 psi (12 volts) or 40 psi @ 13.5 volts.

In fact @ 70 psi the wablro makes 180 lph @ 12volt and 220 @ 13.5 volts.
So depending on which voltage the t-rex is rated, it could be higher then the GSL392 (Walbro 255). (I have a feeling the t-rex is rated at 12v.)

gsl392.webp


Im currently running a walbro 255 inline and to further my investigation i plan on timing how long it takes to fill up a 1 gallon jug at the end of my fuel line and also plan on doing the same with the t-rex as soon as i get it..

Just thought you guys looking to put on a supercharger or turbo would like to know about this. (especially to find out if the walbro puts out enough fuel like i don't think it did for me..)

BTW this is one of the most ideal ways to figure out which fuel injector size you can run.
 

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BlueOvalStangGT: you have a PM

Does anybody know the fitting size on the t-rex.. I know that the gsl392 is just an 1/8 pipe fitting... Thats almost like hooking up a fire-hydrant to a garden hose...
 
95stangGT said:
Whats the difference between a walbro in tank 255 lph and an inline walbro 255 lph?
I got a turbo kit I bought so this just confused me as to what I should go as for a fuel pump.
Well they are two completely different pumps... With any turbo or supercharged application you should run both a good intank and inline pump. The intake really acts as a feeder to the inline pump though.