Ls swap return-less fuel system question

[Roblq84]

the setup I have is a Cammed lq4, with ported 243 heads, fitech tall manifold, fitech fuel rails and 55# injectors, it’s going to Be ran N/A for now shooting for around 400-450 hp.

20 gallon fuel cell, -6 feed to a 255lph pump, into the c5 filter/regulator, returned into the tank also through -6, I’m going to install a breather/check valve on the other unused return port of the cell.

My question is, when feeding the fuel rails, would it be advantageous to have a Y split fed into each rail, and a crossover at the opposite end, assuming this is the parallel way, which I’ve heard to possibly have issues of vapor lock

Or just feed into the back end of one side, through the rail, out through the crossover to the other rail, and than cap/deadhead the back of that rail in series?

Thanks!

 

[64nailhead]

Are you using filter with the return port on it? (I’m confused a little by your opening comment)

If you are, then I’m opinionated on this, so hold on. Take that Corvette filter and returnless rails and chuck them. Install a budget manifold referenced regulator and proper return.

 

[Streetbu]

There are many known issues with the corvette filter/regulator setup. Mainly most of the aftermarket ones don't work properly. If you're not going to be boosted, drop in a Holley fuel module assembly and be done with it. Much easier, & dead simple. I love mine.

That being said, it doesn't matter how you feed your rails, either way works fine.

 

[Roblq84]

the rails are not “returnless”, they’re just aftermarket rails which can be plumbed however you like. Ive also been hearing about issues with the c5 regulator/filter, but I have a fuel pressure gauge to check what’s actually
Going to the rails. On the initial prime/startup I will see if I like what the pressure is since it’s an oem product, and again it has a cell, and requires an external pump which I cannot use the Holley module

 

[64nailhead]

It will idle fine with that filter, but the pressure will potentially be all over the place during throttle pedal changes.

Time will tell.

 

[nycutlass]

Sounds like your going to build this in stages if so , i wouldn't do a 255lph pump your going to run out of fuel real fast. you can get a Walbro 450LPH 800HP on 12 volts and up to 950HP give or take on 13.5 volts for few pennies more, i agree with 64nailhead get rid of them Corvette filter and return less rails and chuck them. again few pennies more and you can have a real regulator and return system. you can do a camed 6.0L and hit 544hp easy with stock 799/243 heads mill 30 off the heads and get more

 

[Roblq84]

Sounds like your going to build this in stages if so , i wouldn't do a 255lph pump your going to run out of fuel real fast. you can get a Walbro 450LPH 800HP on 12 volts and up to 950HP give or take on 13.5 volts for few pennies more, i agree with 64nailhead get rid of them Corvette filter and return less rails and chuck them. again few pennies more and you can have a real regulator and return system. you can do a camed 6.0L and hit 544hp easy with stock 799/243 heads mill 30 off the heads and get more

the 255 is good for 600+ especially N/A, and I kind of doubt a Cammed lq4 will put out 500+hp even with ported 243 heads,

 

[nycutlass]

COMP Cams LSR Series Hydraulic Roller Camshafts 54-469-11
look up Richard Holdener on you tube if your interested in a proven dyno pull with full results. i have it done with 799 heads milled

 

[Roblq84]

COMP Cams LSR Series Hydraulic Roller Camshafts 54-469-11
look up Richard Holdener on you tube if your interested in a proven dyno pull with full results. i have it done with 799 heads milled

Well that makes me feel a lot better about what to expect haha

 

[nycutlass]

all the thinking is done for you, just turn the wrenches now. refer to the posts above you will easily be doing 500hp rear wheel