This will answer your questions:
Fuel Pump Selection
Those pumps aren't meant to be speed varied like that for returnless. Think they may have been a miscommunication.
Got new fuel pumps installed and...
- Thread starter Molon Lave
- Start date
This will answer your questions:
Fuel Pump Selection
Those pumps aren't meant to be speed varied like that for returnless. Think they may have been a miscommunication.
The diagnosis doesn't sound off. As long as everything else was checked first. The issue is the parts you were recommended. I don't blame Lethal (yet) as they can only go off what info they're given. But if you said the word "returnless" in any of your conversations they should've known not to go with the 465's.
Which brings up another point.... the fact that your tuner didn't think anything about dropping the pumps in and also saying you don't need a tune for them raises a couple of flags for me.
Messaged back and forth with lethal Blake, guess he reviewed the recorded audio when I called them. Rep assumed that because I mentioned I have lethal’s fuel hat that I was running return style which I’m not. So he recommended the 465s. Point is you can run a fuel hat return or returnless. I feel that since I called them for advice and guidance to choose the right pumps the rep could have been more thorough and helpful in asking me more detailed questions. All they asked was how much HP I’m making. On lethals website the 465s don’t give any description or info stating that they are for return style applications. Details matter. Blake suggested 2 pumps that would have worked for my set up. That’s the info I was looking for from the beginning when I called them. I don’t feel I’m 100% responsible for this screw up, sucks to be me I guess. Lethal’s rating dropped a few notches in my book.
I wonder if these 465s will work right even after a custom tune while staying returnless??
Not according to that chart. If you notice at the bottom the only two pumps that they recommend for returnless are also the only two without check valves. The rest are not meant to be modulated the same way. Returnless pumps need to be able to change pressure and change rate fast. Which is why a retune for larger pumps is recommended. There is a tricky back end on returnless pumps called PID controllers. It controls the rate of response and really crude "learning". My guess from switching stock to that is its demanding waaaay to much proportional demand and either the ECU has no chance and/or the pumps don't have the ability to catch the bounce.
Long short that type of pump doesn't usually agree with that type of closed loop feedback control. They like constant rate or linear ramp with a mechanical pressure control.
That hat can be used for a couple different purposes but my guess your parts supplier, like many in here, my self included thought you were on a return style. Not many upgrade hats to stay returnless anymore.
Don't think 465 work returnless and mega overkill for you. I make 700+ on e85 with 2 of those but return. Not exactly stock replacements.
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For comparison I make 700+ on 340s just to show how big a 465 is
Well, first off, are you telling me that DeatschWerks 9-307-1033 03-04 SVT Cobra 340lph Compact Fuel Pumps (Pair) will work on my returnless set up without needing a tune?
Yeah, you definitely found out correctly. The 465s are meant for the return style setup. I would be getting different pumps or converting to return if you are keeping the 465s. Sucks, but atleast you didnt find out by popping a motor.....
The 465's are great pumps and I would just make the switch to return.
Just curious, what resolution did Lethal offer considering this is partially on them?
I’m probably going to go return style depending on overall costs and making it worth my while paying labor to drop the tank again. I was told by lethal rep that the 465s would fit right into their fuel hat but the connectors weren’t compatible. Not entirely sure if that’s what they meant but it is what it is.
Leaning that direction
Still in the works, looking to see what kind of budget package that Blake can piece together for return style and hopefully get a discount since I feel they’re partially responsible for the mix up and the extra labor I would have to pay. Don’t think I can return the 465s since my mechanic had to change connectors on them.
The cheapest route will be to use the current line as a return and run a new feed line. You should be able to use your current fuel rails as well....and of course a retune. Shouldn't actually be that terrible cost wise.
Keep in mind it may be best to just do both new lines and rails. That way your set if you decide to ever go E85.
Keep in mind it may be best to just do both new lines and rails. That way your set if you decide to ever go E85.
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