What size injectors and Max U.S.?

SixOhh

SixOhh

EPA unfriendly
To make a short story long my SAC 60% overs aren't going to cut it anymore. I am pretty set on sending them to F1 for nozzles and balancing.

My first thought was 100-120 over nozzles but i have some questions...

What is the max u.s. people like to use before harming an injector and why?
i remember old tunes stretching it out to 3100 or 3200 u.s. and i notice that exergy doesn't do any testing above 2800 u.s.

As far as im concerned i will always have a big single pump and a single charger and i am fine with 8-900 to the ground. Now that i have a looser converter i am really happy with my s369 sxe. People told me i would need more fuel to make this charger happy and they are right.

So i want less duration and hopefully that will help with my smoke with a larger nozzle? i know its a double edged sword...

I would love to hear your thoughts on max duration and how far over i should go for my setup. If i ever switch turbos again it would just be for a different single, never larger than a s475 s480ish, but i plan on keeping this SXE for a long while. i just want the most out of it. 150% overs and call it a day? or more to be safe?


-Marcus
 
It's not about harming the injector as much as it's about keep end of injection at a safe point for the rpm you're running at. Bigger the injector the less timing you have to run and the less likely you are to run the injection event to long and melt a piston or something.
Running the injection event too far past TDC is just as bad as Starting injection to far before TDC.
That being said, I don't like anything over 100% on stock bodies.
 
thanks for that insight Dominic.

FI told me they would discuss body tuning with me further after i decided how far over i wanted to go. what do they actually do when they say body tuning?
 
I have DDP 150% overs with body mods in my 03 with an he351 67/67. The 5.9 12mm cp3 can not keep up to these injectors.
I believe the body mods are internal with the pintle? The body tuning is something every injector company does? But maybe that is body mods too?

Exergy and S&S don't do body mods until after 250% over.
 
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You want less duration at higher RPM, while not the most efficient you can run a lot of duration on a truck that makes its power down lower (compounds or small singles). If you see a larger single in your future I would get bit larger injector, maybe around a 200% over to get the full potential and RPM required to use that size turbo.

For instance when the big power guys above 1500hp load a "hot tune" in a high RPM CR, it uses about 1800us which is around stock duration.
 
ramthiscummins said:
What about the 05, 800 hp on them with a 472? 12.38 in the quarter mile?

What size DDP's?
Click to expand...

05s are 150% overs. The turbo is way too small. Ordered a new FI 476/87 to put on. I made those passes and dyno pulls in my tow tune. I did 951rwhp on PDDs dyno on the race tune with spray uncorrected.
 
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