bgreen

Hey guys, I'm doing either a 4.8 or 5.3 in my Jeep... normally I'd post this in the hybrid section, but this question applies directly to the truck motors.

I am putting it in a Jeep Wrangler, the stock fuel system is a deadhead (no return, with regulator intank) and runs static 49psi. I understand the truck setup runs 58psi, vacuum regulated, but it would simplify things greatly if I could just use the Jeep regulator (the regulator is part of the filter, as well as the top of the whole fuel pump assembly). I have the intake/fuel rail & injectors from a 2000 6.0L motor that I will be using. I will be using LS1 Edit as well.

My question is, can I run the 6.0L injectors at 49psi static, as long as I change the injector flow rate to correlate to that static value? I'll have to dig up the injector flow rates, then verify that those are the injectors I do actually have.

More or less, will the 6.0 L injectors flow enough at 49psi to supply a stock 5.3 L's fueling needs?

Thanks for any input

parish8

iTrader: (6)

yes, i think so. prety sure the injectors will feed a stock 5.3 at that lower presure, if not you can look for a set of 8.1 injectors they will feed it forsure. you will need to change the flow rate in the computer with something like ls1edit and it won't be a linear flow rate anymore. the vacume controled regulater is what keeps the fuel flow equel under varing loads but you can program this with ls1edit to change the flow rate based on load. the ls1's in the cars have a set fuel presure and no return and the computer adjusts the flow rate for diferent loads on those cars.

i am prety sure that the 6.0 injectors would feed a 6.0 even at the lower fuel presure as long as you don't try and hop it up at all. i am big fan of the 6.0 and if you are looking for more power you should go strait for the 6.0

here is a site http://www.rceng.com/technical.htm with alot of info on injectors, i think the 6.0 has 24#(not sure) injectors at 59psi, and is rated at 300hp, so go figure out if it will work at 49#

parish8

iTrader: (6)

just did some numbers form that site and if the 6.0 injectors are 24# at 59psi you can convert that to 49psi and now they are 21.8#

now you can calculate how much hp the 21.8# injectors can handle

at 80% duty cycle and .5 BSFC = 279hp
at 90% = 313hp
at 100% = 348hp

looks like those injectors(if they are 24# will handle 300+ hp prety easy at 49psi

BigTex

iTrader: (16)

Parish8, remember thats HP at the flywheel before drivetrain loss. So those injectors might not handle 300 at the rear @ that fuel pressure.

parish8

iTrader: (6)

yea, all of those numbers are fwhp, what i was geting at is that the 6.0 injectors should be ok to feed a 6.0 even at 49psi of fuel.

really slow truck

yeah just dont plan on doing any serious mods though, i wouldnt want to spend money on injectors and then after i mod the car a little it is already getting up into the 90+% duty cycle range

bgreen

Cool, this is pretty much what I gathered too.

I probably won't hop it up at all, but it is worth taking into consideration that it will have a high flow intake, stock exhaust manifolds, but probably no cat & a high flow exhaust. So I'll probably make the most of what fuel I supply <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I'll be datalogging and such, so I'll find out for sure if I'm running low on fuel, if so I'll step up to the 8.1 L injectors, and keep the low fuel pressure. It'd be cheaper than running a new return line, and fittings and such probably.

Heck, 280-300hp in a Jeep is more than enough for me <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

thanks..

<small>[ September 24, 2002, 08:17 AM: Message edited by: bgreen ]</small>