g8lover

Hi,

This is a really dumb question but just wondering what you think..

If someone tells you that on the dyno it shows your at 125% injector duty cycle... what does that mean?.. and will this cause an issue if your tune is correct?..

tHanks

HCI2000SS

iTrader: (2)

It means it's time for some bigger injectors lol. I'm not really sure how to explain the details of how and why it can read higher than 100% but I have in fact seen this before. Basically all you need to really know is that your injectors are maxed out, it will determine the state of the overall tune, so it's time to upgrade. Assuming your dyno operator is correct of course

g8lover

yea.... now engine is toast and needs complete rework.... 125% seems to mean the car wants alot more fuel than the injectors can put out... lol.....

T/A KID

iTrader: (12)

whoever was working on it, should have known better

HCI2000SS

iTrader: (2)

Damn thats not good. So was this person tuning it or just dynoing it, and did it blow on the dyno or afterwards?

g8lover

Engine was still running when pulled apart... found exhaust valves stretched and could have been like that forever... I just know the dyno was run 6 times with duty cycle all messed up and after i picked up car was when tuner actually told me i needed to mix race gas in at a high level to make it not go lean... tuner was remote and didnt see all what the dyno person was doing... one issue with having a person who doesnt tune and doesnt understand it run the dyno and not have tuner handy and available... lessons learned ..

gametech

iTrader: (1)

This is the kind of issue that drove so many of us to tune for ourselves.

RonSSNova

iTrader: (3)

Kind of sketchy info here.
What size injectors?
What fuel?
How much HP was it making?

Duty Cycle is a calculated number based on RPM and Injector Pulsewidth
Entirely possible the tune is hacked up and that data is wrong.
Or the tune is fine, and the injectors are indeed too small.

It's certainly possible to have duty cycle over 100% but still have a flat fuel curve.

Ron

JakeFusion

iTrader: (7)

Yep^

And you watch it lean out big time up top.

T/A KID

iTrader: (12)

Tuner sounds like an idiot to me.. who did it?

TrendSetter

different fuel wouldnt help get your duty cycles right if its at 125%
idc is a calculated number, it can be calculated and reported above 100% but that just means the injectors are never closing and you are at 100%. anything over 100% idc wont flow more fuel.