3800 Returnless fuel system questions

v6buicks

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So after all that talk about finding minty PAUs and top swapping a Lacrosse, I stepped back for a minute and thought about how dumb I was sounding.

I know. I'm a mess when it comes to choosing my daily, but that '04 Comp G I keep bringing up is just too damn good to pass up. I started that process and I'll be going to inspect it and pick it up soon. We're pretty certain it needs a fuel pump. I just don't really know what I'm getting into as far as Series 3 returnless systems. What's the scoop? If I'm going to get a new pump, I'd like to upgrade it right away. Can I just buy any run-of-the-mill in-tank pump like I would for an S2 car? With it being an '04 I hope it still has an access panel. That'd be nice. Is it possible or worthwhile to just change the fuel rail and sender and add a return line?

Thanks
 
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sktchy

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I think I'd run a return line with a boost reference regulator and just go that route if your upgrading the pump. The returnless is going to cost you a few ccs of flow and the regulator is in the pump assembly itself in that kind of setup.

That being said somethin somewhere probably has a bigger pump you can modify and keep that style fuel rail but it's nothin I know off the top of my head.
 

1quick

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04 should have the access panel it was the last year for it, you can run any regular pump there is a return but it’s right at the top of the canister and not at the rail, fuel pressure is higher on the return less it’s around 60psi if I remember right, I ran a 340lph pump in my 04 and ran out of fuel around 520whp, switched to a walbro 450lph pump and it was fine
 

sktchy

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04 should have the access panel it was the last year for it, you can run any regular pump there is a return but it’s right at the top of the canister and not at the rail, fuel pressure is higher on the return less it’s around 60psi if I remember right, I ran a 340lph pump in my 04 and ran out of fuel around 520whp, switched to a walbro 450lph pump and it was fine
Will the returnless do a rising rate with boost pressure like the return style setup? I would assume so but I know injector flow rates have to be done different in the pcm for either way
 

1quick

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Will the returnless do a rising rate with boost pressure like the return style setup? I would assume so but I know injector flow rates have to be done different in the pcm for either way
Stock no, if you re plumb it and add a regulator up front you can make it do whatever you want, 60psi is the same fuel pressure a raising rate set up would have at roughly 17psi of boost, they normally start at 43psi and raise 1psi per psi
 

v6buicks

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04 should have the access panel it was the last year for it, you can run any regular pump there is a return but it’s right at the top of the canister and not at the rail, fuel pressure is higher on the return less it’s around 60psi if I remember right, I ran a 340lph pump in my 04 and ran out of fuel around 520whp, switched to a walbro 450lph pump and it was fine
Thanks! I wouldn't want to be pushing this car hard at all. It's just a daily, so I'm hoping to throw a pump, injectors, and smaller pulley in it. I have a 3.0 pulley, which I'm sure is fine for the engine with E85, LS6 springs (already installed), and a full stack (already installed). However, I'd fear for the stock rebuilt trans. 3.4 seems a lot more reasonable.

Idk why my buddy never pullied down. The engine bay was redone done so nicely. It even has the modular pulley and belt wrap, but stock size SC pulley.
 
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v6buicks

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I doubt your gonna outrun the a good OEM pump at that power level but on e85 you'd be close. Throw some 60s at it and push that duty cycle up lol
I'll just yank the 80s out tof the Camaro since they're already EV6 and get a new set of EV1s for the Camaro. I'd say 80s for errthang but the Camaro really needs bigger to move on.
 
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My 04 GTP has the access panel in the trunk. I just dropped a 340lph pump in it and it was just like the fuel pump module in my 01 Regal. So nothing different about installing it. The stock pump couldnt keep up on e85 with a 2.8". I really miss my 01 Regal GS but im slowly starting to get used to the GTP. Being lowered and having the front lip on sucks when parking. It will hit any parking block ive seen. looks cool, but i dont like letting anyone drive it because that shit would be ripped off right away.
 

v6buicks

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My 04 GTP has the access panel in the trunk. I just dropped a 340lph pump in it and it was just like the fuel pump module in my 01 Regal. So nothing different about installing it. The stock pump couldnt keep up on e85 with a 2.8". I really miss my 01 Regal GS but im slowly starting to get used to the GTP. Being lowered and having the front lip on sucks when parking. It will hit any parking block ive seen. looks cool, but i dont like letting anyone drive it because that shit would be ripped off right away.
Glad you chimed in! Geez you have a 2.8 on your GTP? Is the trans stock? How's she doing? Lol
 
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Glad you chimed in! Geez you have a 2.8 on your GTP? Is the trans stock? How's she doing? Lol
It had a 3.3" when I bought it, and it really wasn't impressing me at all. The cam lacks some low end and it was only making 7-8lbs of boost. I drove it like that for about a year, then Marty (M-dogg on here) let me barrow his 2.8" a couple weeks ago. Wow, I know dropping .5" is pretty substantial, but it feels like different animal. Now its right at the end of the map table, so around 14-15lbs. The trans is supposedly built with 300m input shaft, gemini chains and shift kit. I guess we'll see haha. Its still shifting nice for now haha
 
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