2 fast 2000

iTrader: (4)

I'm a little confused on the fueling part of my 416 LS3 build. There is so many options out there as far as injectors go. I'm looking at getting a set of fast 50lbs injectors, but is there a certain style I need? There is ls2 style, Ls1 style, ls7 style, L92 style and so on and so on. Not to mention there is different psi ratings also. Will any of the LSX style injectors work? And will the fast fuel rails I had on my Ls1 set up work with these injectors. Any info????????

BlownVette 2001

iTrader: (2)

How much power do you plan to make ? I would do 60lb injectors to give yourself room for growth.

You did not state what fuel pressure you plan to run and this too effects flow rates.

Also are you going FI or NA ? as there are different consumption rates.

Your fuel rails should work with the LS3 manifold and depending on your choice of injectors you might need some spacers.

Most vette guys set their fule pressure between 58 - 60 pounds.

2 fast 2000

iTrader: (4)

I was wanting to keep the fuel psi around 60. I'll be N/A for a little while, but plan on hitting it with kits of juice. I know nitrous dosen't require big injectors like the blown cars, but more or less on fuel voluming. I got 2 255lph fuel pumps for that. Just checking to see if anybody could lend me some info. I'm a old h/c guy, so this is the first fully built motor I'll be running in the car. So some of this technical stuff is above me.

SweetS10V8

iTrader: (4)

What intake are you going to run?

LS3 intake takes the short LS3/LS7 style injectors.

If your going to run the FAST LSXR 102mm, when it comes out, it takes the LS2 longer version. During the time until the LSXR releases you can use a .600" spacer between the intake and fuel rail to adjust the height. Probably could find a nut that's .600" thick or use a bunch of washers.

The fuel rail is the same part number for both LS2 and LS3 intakes, so your good there is you have one already, no matter what. The difference is the amount of room left for the injectors, which is done with the design of the intake.

I called FAST for this exact reason, I'm waiting on their intake but I also need injectors and want to get the right ones the first time! I put on a set of Lingenfelter CNC LS3 heads, Comp Cam, 1 3/4" LT headers, and that intake when I can get my hands on one! So I definitely need a set of injectors and want the drop in replacements that FAST has.

Edit: I forgot, they also explained that if the part number ends in 7, its the short LS7/LS3 style injector. If the part number ends in 2, its the longer LS2 style injector.

2 fast 2000

iTrader: (4)

Hmmm, okay but I'm running a fast 92mm intake. So I should be fine with buying a standard LS1 type injector.............right? My fast fuel rails are off of a LS1, so I will have to run a LS1 style injector.

bigdsz

iTrader: (1)

Yes, Fast 90 and 92 intakes use an LS1 injector. You really don't need 50-60# injectors. All I've got are Ford 30# which are 35# at 4 bar on my 408 with a Racetronics fuel pump no issues.

SweetS10V8

iTrader: (4)

What LS3 intake are you planning on running?

LS1 injectors are too long for any LS3 intake, youll have to use a spacer between the intake and the fuel rail if you keep them. But if your buying new, it depends on the intake you plan on running.

For Example; Im planning on running the FAST LSXR 102mm Intake when it comes out, which takes the longer LS2 injectors. But until then I have to run the stock LS3 intake which is designed for the shorter LS3/LS7 style injectors.

So Im using a nut for a spacer until I get the intake Im going to run.

2 fast 2000

iTrader: (4)

I'm running a fast 92mm on my LS3 build. From what I understand it should be okay with the LS1 type injectors.

sroach20

iTrader: (31)

you will need the spacers and the thicker orings for the bottom of the ls1 injectors. lingenfelter and katech both carry the injector orings.

SweetS10V8

iTrader: (4)

You cant run a FAST 92mm on LS3 heads. Havent you seen the difference between a cathedral port and an L92/LS3 port??

2 fast 2000

iTrader: (4)

This maybe true, but I don't have LS3 heads. I have some Trick flows

SweetS10V8

iTrader: (4)

You could of said that earlier...... Ive been trying to help you since post #4 based on saying you had an LS3.

2 fast 2000

iTrader: (4)

Yes and I appreciate you helping out as much as you can, but the only thing I need help with is the injectors. Some people say I can use Ls1 injectors, some say I can't, & the rest say I can use them as long as I have spacers. Does anybody really know??????? Because I'm lost now.

sroach20

iTrader: (31)

you can use the ls1 injectors without any spacers or anything since you are using the standard fast setup. we all thought you meant ls3 with the ls3 heads.