Started doing some tuning tonight on my new engine and turbo and quiclky noticed that I am maxing out my 680 injectors at only 20 PSI. I plan on running 30+ PSI and N20. What injectors would you recommend.

 

i had 880's for my 50 trim but maxed them out when i switched to my gt35r. now i have to go bigger. 1000's? and be done with it.

 

i have 880s on my 57 trim......just a bit bigger than a 50 trim .

 

ed, not sure if 780s are large enough but i have a set just sitting here if you want to try them. give me a shout.

 

880s should be plenty but I would recommend a stand alone for tuning purposes for anything larger than 780.

Also, just out of curiosity, why you're using nos? Usually nos is used to spool the much larger turbos in 4 cylinder applications.

 

Not using it for the spool, just the shear power. I built a pretty stout engine so why not through a another 100 HP at it. Thing is that I really want the power of a big turbo, but I hate lag. So I figure that the combination of the 50 trim and a 100 shot will give me the best of both worlds. Next engine that I build is going to be designed as a nitrous engine and I will be running stupid amounts through direct port. Please keep it on topic for all the nitrous haters looking to jump on

 

Hit me with a PM and let me know how much. If you are literally willing to let me try them and see what the duty cylce is, I would go for that. I suspect that they are going to be too small though.

 

You can tune 880's fine on a stock ECU. I am running 1000's myself.

 

WHY??? i have 1000cc on stock ecu tuned perfectly with no issues. as do many people.

 

I would go with 880's if you plan on staying with anything in the 50 trim territory.

On a side note, if "larger" injectors are scaled properly in the rom they should work flawlessly. But there does come a point where they can become too large for an OBDII vehicle to idle and pass emissions properly. Injector on time is just too short....
At the point where you are running larger than 1000cc....or more than 600WHP.....the vehicle should be running a standalone.

 

What duty cycle are you seeeing with 880's at high boost? I eventually want to run E85 so if I can pull off 1000 cc injectors with the combination of the utec and a flash I would like to do that.

 

Normally on average you will see 67-77% dependant on cam profile and fuel type.
E85 is not a good idea with 880's alone. 1000cc's would be a minimum along with more than just one walbro.

 

I'm running 680s with my AMS 50 Trim, hit 400whp on pump alone without much adjustments at a perfectly safe boost & duty cycle level.

 

Can anyone definitivly tell me what the duty cycles that they are seeing on race fuel at high boost with 880's around 500 WHP?

 

a 50 trim at 500whp? on a realistic dyno your not gonna see numbers like that.