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Max Spray on Stock fuel rail

7K views 21 replies 8 participants last post by  justanotherssuv 
#1 ·
I was wondering what the max you guys spray when taking your fuel off the fuel rail port. I'm looking to up my plate to a 250 shot but I'm still feeding my solenoid off of the fuel rail. I do have a walbro 450 in the tank instead of the stock fuel pump. I already made 550rwhp on a 150 shot. I'm using a Nitrous Outlet plate system on a stock intake.
 
#3 ·
I don't think its so much as how much you can spray off the rail before you get to where the rail is holding you back on power in general. Pcm makes a fuel line y for that reason and to keep fuel pressure consistent.
 
#5 ·
with a single 450 in the tank i had no pressure drop spraying a 250 off the rail. But i dont know if it was a true 250 shot. the pills say yes but im not sure if the plate was flowing at 250
 
#7 ·
A couple things.

1. Pulling off the rail will always cause a pressure drop when the fuel solenoid opens, but a bigger pump helps.

2. Depending on plate design it may not be able to support a 200+ shot

3. You need a feed line and solenoid capable as well.

4. Fueling is also dependent on how much of the pump is being used up by the motor. Is it a stock LS2 with headers or a 12:1 416?

With that said, I would not spray over 175 on a plate designed for a 90-102 front inlet manifold, especially pulling from the rail. If you want to spray a real 250 shot a Direct Port or at the very least a dual nozzle system and a stand alone fuel system would be the way to go.

No motor will last very long trying to spray 200+ off of a standard plate and pulling from the rail.
 
#11 · (Edited)
I have a ported LS3 headed forged 370 iron block in my truck with a billet FTI 3200-3400 converter and a built 4L70e. Nitrous Outlet told me that they have many customers hitting their stock intake manifolds with a 300 hit off the plate. They said the truck manifolds distribute the spray really well up to 300 but they suggest a DP for anything north of 250. I'm looking at 250 max using a 4 an feed line and br7ef spark plugs so I'll keep an eye on my wideband and give the plate a try. Ill see what is the max the truck will support off the rail, I'll stop at whatever hp shot it ends up being cause I'm not looking to step up to a DP.
 
#19 ·
I'm def. going to read the plugs.
 
#20 · (Edited)
Some good information in here. But just to go over a few things.


You will notice a pick up on a -6an line when spraying above a .073 jet (175hp). It always makes since to run a 6an main feed line from the get go, that way you are future proofed. But that line will support up a .082 jet (225hp).

Yes we have A LOT of customers on a .099 jet+ with great sucess. A customer of ours was using our EFI plate and held the LS1 stock bottom end record for years, up until he switch to our puck system. And now he is going even faster.

Our EFI plates offer the best distribution out there over any other manufacturers. Now there is charastics of using an EFI plate. Like the front two cylinders getting more fuel than the back two, do to the way it enters the intake manifold. But with a good tune, it is nothing to crazy for up to .088 jet.

Every customer and car is different, for the guy going to spray every once in a blue moon on a .078- 0.088 jet, the plate is great. It is simple to do jet changes, looks really clean and it is easy to tech out and help the customer out during the install. A fogger (direct port) has a lot more moving parts. But we can really dial in that tune up and make all the changes do to weather and what not. For the guy who is trying to go all out, that is a heavy racer, and will show the car a lot of stress on a daily basis. Then I would really push a fogger set-up over a plate.
 
#22 ·
I went a -6 feed right off the bat and refuse to pull off the rail. If you're gonna spend the money on a built engine and converter, dont half ass the nitrous and try pulling off the rail for a 200+ shot. Pic just because lol

 
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