Someone skool me on injector sizing

slc6oh · Apr 30, 2016

so , currently on an s362 and stock sticks and stock fuel pump.

being able to tow fairly heavy (10-15k) up steep, long, hills in high elevation
is pretty high on the priority list, but kinda thinking some sticks might help get this charger going faster? Its not bad by any means, but I feel like theres some left on the table.

body size is basically where your getting your top end and nozzle size is your low end/drive/towability correct?

something like a 190/30? be worth lookin into ?

or is that too much?

Fox hunt · May 3, 2016

Nozzle size plays into your top end. A larger nozzle can dump more fuel with a shorter pulse width. With 30% nozzle you can have fuel pulled to where a 190/30 acts like a 155-190/30. But on a high pulse width tune the 190/30 will have more fuel to be able to inject vs a 155 or 175. Most people think a 30% is about the smallest nozzle to be a to completely empty a 190 and the depends on you pulse width as well. Charlie or someone else can got into it a bit more, but the 190/30 injector seems to be pretty popular for those who tow and want a ~550hp truck when not towing

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slc6oh · May 3, 2016

And at what point do i need to start looking into a bigger fuel pump?

Or more oil?

powerstrokecrzy · May 4, 2016

slc6oh said:
And at what point do i need to start looking into a bigger fuel pump?

Or more oil?

190s and you'll need more fuel. Oil should be OK on a healthy pump. Some have great success with the juggerpump mod for 190s but that didn't work for me which is most likely attributed to the 75% nozzles. Went with a 6.7 pump and all is well.

6.0 Tech · May 4, 2016

With any aftermarket injectors fuel is recommended. At least a regulated return. I have been told 205s are the gray area on a stock oil pump. If you are going to do 30 nozzles, id recommend stepping to 205s. They will run just like 190s until you are on it hard. I have been told that 205s is the max a 30 nozzle will be able to empty.

Mdub707 · May 4, 2016

FWIW, I can watch fuel pressure drop pretty hard on stock sticks with a tune. Though, I also have measured fuel pressure behind the heads, instead of the fuel bowl like most. Measuring at the fuel bowl it looks OK. Behind the heads and pressure drops HARD.

I'd recommend a pump for anything over stock honestly. Either a 6.4 stock pump as a lift pump, or swap the whole setup out for a 6.7 pump, those seem like decent inexpensive upgrades.

I'd probably do a 175/50 or 175/30, something like that, with this turbo. It's what I wanted to do with mine and just never got around to it. Talk to Rykan at Holders and see what he recommends.

I know Matt ran this turbo with 225's for a while.

04cr450 · May 4, 2016

I'd go to 205/30 or 75's. When I had the 364.5 it cleaned up my 205/75's on a race tune to slight haze.. fwiw I also use a oem hfcm pump with a 6.4 pump as a pusher. Regulated return and I hold steady fuel pressure at 60psi. That 62 is not that much smaller than the 64.5... I'd say go bigger on nozzles. It will be a fun combo.