I will be putting the pump in in the next couple weeks so I will let you know how it goes

 

so I have returnless when upgrade bigger pump what would I do with regulator in pump since I want boost on my 06 Silverado. Can you share with me this experience?

 

Leave it, youll just need to compensate for the lack of pump with extra big injectors.

This is of course assuming you dont want to convert to a return-style.

 

This last part confused me. Yes it's old, but Idc. So your saying to stay return less and toss a 450 in with 80lb injectors and should be good for around 700-800hrsp?

 

With 80lb injectors and a walbro 450 assuming max of 20psi of boost:

Returnless, base pressure set to 58psi -Injectors flow 315 l/hr and pump is 380 l/hr so you are injector limited and 315 l/hr is about 720rwhp.

Return, base pressure at 58 - Injectors flow 385 l/hr and pump flows 328 l/hr so you are pump limited and 328 l/hr is about 750rwhp.

For comparison, with a return setup with dual walbro 400s - Injectors are 385 l/hr but pumps are 571 l/hr so you are injector limited and 385 l/hr is about 883 rwhp.

Same setup with returnless and you are still injector limited, just like with a single 450. So with a reutnless setup it is not useful to have huge pumps because you will mostly always be injector limited.

I used this spreadsheet I made to figure this all out: https://www.performancetrucks.net/fo...p-flow-510434/

 

I think he is more confused by the fact that you want to run a 450 in the returnless system. What do you have to do in order to accomplish that?

 

Just replace the stock pump with it...

Only 2 connections; fuel output and electrical. Connect the hose to the regulator and connect the wires. I recommend upgrading the wiring connections to 12ga or better.

 

And you're saying that wont overpower the stock FPR in a returnless system?

 

I dont know, maybe a little, but thats really not a huge deal as long as its consistent. Its not near as dreadful as everyone makes it seem, its just like having the regulator set to a higher pressure.

 

FYI my stealth 340 over powered my stock FPR
I went to a return system