This was split off of Jerromes fuel post. Figured this could be a useful thread all by itself. ;)

Originally posted by BigBald
What is the highest Duty cycle you should tune too? I have 550s right now and with this tune i am getting my highest of 75%. I was told 80% is considered perfect and anything more then that is the danger zone. If this is the case then i want go no higher then 15psi on this turbo until i get bigger injectors.

80-90% is ideal. I've heard of people going over 100% when maxxing them out. Anyone who has maxxed out injectors care to chime in?...

holy shit.... math is fun!

I know people who are running 100% (perhaps even higher IIRC, a guy in Rochester said he was running perhaps 130% when maxing his 660's with added FP to run 11.6's, but I could be completely misremembering what he said). It shortens the life of the injector and means failure of an injector can cause significantly more damage (a 100% 660 failing is much leaner than a 80%). I really don't know a whole lot about the duty cycle aside from the ideal range, but I'm hoping I won't run into that issue with 850's.

It can't be that good for the injector to be firing at all times with no down time.

Does the >100% come from a greater FP (and subsequent greater volume of fuel than normal being pushed through a constantly open injector)? Am I even close here? Did I go insane?

Originally posted by HybriDSM
Does the >100% come from a greater FP (and subsequent greater volume of fuel than normal being pushed through a constantly open injector)? Am I even close here? Did I go insane?

I don't know if it comes from higher FP but I think it would be safe to say you'd need higher FP when running close to/above 100%.

The main thing I know about injector d/c is that it is " impossible " to achieve a higher duty cycle than 100% , after u surpass 100% say 120% your running without 20% of the fuel that you need. An injector can only flow as much as its maximum duty cycle, no matter what % shows up on the log. I ran my 510's w/16g at 120-125% duty cycle for about 6 months, i know its not good for the injector, but they lasted fine. I'm on 780's now, 65% dc lmao !

Originally posted by DSMTunerS95
The main thing I know about injector d/c is that it is " impossible " to achieve a higher duty cycle than 100% , after u surpass 100% say 120% your running without 20% of the fuel that you need. An injector can only flow as much as its maximum duty cycle, no matter what % shows up on the log. I ran my 510's w/16g at 120-125% duty cycle for about 6 months, i know its not good for the injector, but they lasted fine. I'm on 780's now, 65% dc lmao !

Yeah i need to pick up some bigger injectors too. I try not to go above 80% on mines. God forbid one of them fail, which i seen happen.