liltoxic97

iTrader: (1)

Tried searching and all the answers that I'm finding are confusing me even more than when I started reasearching! I would like to do a 03 6L sbe and stock 317 heads with an Ls6 intake. Cast s480 t6 with a 44mm wastegate somewhere in the ballpark of 15psi. Would like to be around 800hp.

Now, i have a racetronix 255 with the Hotwire kit and i realize this probably isn't going to fuel my goals. Would like to use 80lb Siemens injectors also.

Now I'm wondering what I should do for my fuel pump, feed line, return lines, rails and regulator. I considered putting a fitting on the back of my stock tank and running a magnafuel inline pump up to whatever fuel rails we find. But once I've researched I've seen people using the stock fuel lines and fuel rails. But I can't seem to comprehend how people are using the stock feed and rails. Any help/ info on this would be greatly appreciated!

ScottyBG

Here is how I would do it. Or did it rather.

https://ls1tech.com/forums/fueling-i...ct-review.html

I did a lot of research on this as well, and while you can use your stock fuel lines, its not really the right way to do it IMO. The stock fuel lines and rails will flow enough to meet your HP requirements, as long as you have enough pump/pumps to drive it through. It's like you can lift the earth with a lever long enough. Here is the catch. The maximum the intank regulator can handle without some pressure creep is 255 lph. That is why Racetronix will not sell their single fuel pump kit with a 340 in it, and only a 255. I was told this directly by them. Even a single 340 lph pump correctly wired, out flows the volume the stock intank regulator is rated to handle. When you exceed the volume rating on the regulator, pressure begins to rise as it can't let the fuel through it quick enough. So with a single 340 you may have something like 65-73 psi (depending on the individual pump and regulator, there is some variability) rather than the 58 psi you should have at idle. Once you get into the throttle, enough fuel is consumed by the injectors that pressure drops back to the regulator's setpoint of 58 psi, because there is not enough fuel flowing back to the regulator to overwhelm it any longer. Many people don't even realize this because their tune takes care of it, they pull a little fuel out of it at idle to make up for the increased pressure and it works fine. Most people that run stock lines are not using a fuel pressure gauge either so they don't know where the pressure is. They don't even realize this is why they have to pull a little fuel out at lower power levels, they just set the VE table so the car runs right off the wide band. Probably maybe even believe it is because their big cam is really inefficient down at idle which is also true. So the regulator pressure creep is masked, and without a gauge on rails there is no way to know.

If they run dual pumps, the second pump is usually only brought on with a hobbs switch, which is boost referenced, or can be on a WoT switch like used on NO2, so it is not a factor at idle to give the stock regulator fits.

So there is how they make it work, although I don't think the majority of consumers setting up fuel systems really understand it. They see someone else do it, so they do it.

My thought was to do it what I believe to be technically correct, have a boost referenced FPR, and lines that can easily handle the volumes of fuel I was looking to need now and in the future with E85. This should make tuning and troubleshooting easier, not having to worry about transitioning fuel pressure, and giving me a system I can grow into, even when hopefully someday I start to exceed the capability of the stock fuel rails and lines.

Hope this helps.

liltoxic97

iTrader: (1)

Awesome man! Thank you very much! Had I found your write up beforehand I wouldn't have had any questions! Very informative and detailed thanks for the help!