ok, so i need to know what everyone's IDC's are for a stock set of LSJ injectors. I've seen them usually in the 90% area. I dyno my car and MAX i got was 62%. ??????

 

That just goes to show how much IDCs dont really matter..

You have to look at PW (pulse width).. Thats where youll find the useful information.

 

less dynamic airflow, thus less fuel is needed to maintain AFR.

generally you'll have to lean out the tune to pull "perfect" AFR's while doing a pull.

dynos are fairly useless.

 

well this was logged with hptuners and im confused because of such a drastic difference

 

Your car isn't pushing enough air or your maf is screwed up

 

stock i was 137% this is due to a number of things, first off the stock tune commands 10.8 on a 07 which is for sure way way too rich and running it to 7000rpm used about another 20% more than what it would have at 6500

 

if my maf was messed up my afr's would be off by a notable degree

to my knowledge IDC is linked to pulse width. i believe the equation is IDC=(PW*RPM)/1200.

i cant give you my exact PW atm as im on my work comp. maybe i could see what everyone else was logging for now?

given the above with a 58% duty cycle i'd be at about 10 ms at 7000rpms. how does this correspond with anyone else logs?

 

its also kinda hard to gage without knowing some mods you may have and what the AFR read. Type of intake, exhaust, header, dp, tuned or untuned? What gear were you dyno'd at. My 2nd gear pulls have a higher IDC's than a third gear pull.

 

ok mods as dynoed are: catless downpipe. thats it. stock intake, stock header, stock catback 'n all. afr's ran at a consistant 11. the pull was also done in fourth gear for the near 1:1 ratio

 

With my little expierence I'm gonna say that your IDC's are about right. Once you start leaning it out with an intake, header and exhaust you should see your IDC go up, especially if you get a tune with it.

 

well thats the thing,im getting ready to tune with friend (im learning). our friend brian from dynotune here in columbus says he sees most stock ss's with IDC's around 90% and was confused why mine was only 60. im trying to get to the bottom of this before we go any further. anywho, after work today im doing some logging and gonna try to find out whats up

 

lol... If your fuel trims are not +20's, or your AFR's are not lean and if you have no knock count yourself as one of the luck few.

 

my fuel trims need to be dialed in, but they're nowhere near 20% lol. afr is consistant, and guess what, no knock! monitoring with efilive i showed a couple degrees worth of knock, but when retarding the timing it had no effect. checking with HPT i get 0 knock across the board.

 

Is your scanner configured right? If your using a default scanner it will be looking for 2 injector banks instead of the one on the cobalt, and giving you a false reading.

Kevin

 

right, and we looked into that. a little while ago my dynamic air per cylinder was completely whack, couldnt understand what the hell was going on. did a little digging to find is confiured for 2 banks. since then any issue involving a similar situation has been addressed