I'm new to this whole thing. I changed a few minor things to get zero knock at 22psi through third gear.

I think I need new injectors, evoscan is showing 97% ish duty cycle on the stockers.

Thanks in advance, i don't really know what I'm looking at.

 

I dont know that I would trust the 97%. I have tuned cars with alot more boost and cams on stock injectors and a pump and only hit 94. With the WB AFR's not being logged there is a possibility that it might be a little rich. I would contact your tuner and express your concerns.

 

My AFRs at redline are in the 11.0 range. I do some road racing and asked for it to be slightly rich for safety reasons.

 

after looking at some other logs, my timing advance seems low.

the injectors are at 93%... sorry, made a typo, is that acceptable range?

 

try beginning your logging from low rpm, 2500 or so, in 3rd gear wot. Knock occurs in low rpms, just as well as high rpms. All of your logs begin at high rpm.

 

Something Tephra said in another thread got me to thinking about your IDC delimna. I have known for awhile that the percentage it reports is incorrect and attributed it to some safety net engineered in the system. I think it is actually reporting the percentage of the scaled injector not the actual size. SO a stock injector is 560cc and scaled as a 513.

513/560= 91.6% and then 97% of that (or 93% as you pointed out) would drop it somewhere in the high 80's. 93% of 513 is 477, 477/560 is 85.1%. I know of one tuner that has seen IDC's well into the 110 range (which would offer some support of this) and still be able to adjust fuel.

 

Well that puts my mind at ease, thanks.

 

That is very interesting. I have my stock injectors scaled to 472 in order to avoid the high fuel trims messing my AFR. When I log IDC I see an average of 97.8% @ 7500 rpm omn a TBE and drop in filter Evo 9.

If what you are saying is correct, then my actual IDC is much less than that. 472/560=84.29. 97.8%*84.29=82.44. And 97.8%*472=461.6 =>461.6/560=82.43. So my IDC should be 82.43% @ 7500 rpm.

 

Now thats the kicker on my thoughts on IDC. If you log the pulsewidth and did some math based on that (if you could make sure it wasnt affected by scaling) you might be able to prove/disprove.

Based on the data I have gathered and others have it seems to be a good working premise. I have seen IDC's (not on my car) up to 120% where there was still AFR's pretty much on target.

 

so then should the IDC % calculation just automatically multiply by <injector scaling>/560 for stock injectors?

 

Thats my current belief Codgi, yes. Its not hard to change how it logs but I would hate to be wrong and it is actually a little different than that. I do not believe that it is 100% accurate still the way it is. Whether I am 100% right on how its doing it needs to be figured out by someone smarter than me.

 

If we can get confirmation that IDC calculation should be done based on injector scaling rather than injector size, then that will prevent a lot of unnecessary injector purchases. I hope someone will step up and confirm this. If confirmed, then this is huge.

 

On the dyno, I have seen AFR's that where once tuned at 11.0/10.9 at around 6800/7000 start wondering up past 11.2 with IDC's over 100% as logged by evoscan.

They where able to be brought down a tad with Fuel map adjustments but when comparing the Fuel maps to evos that aren't at 100% IDC, it seems to tell me the evo is starting to run out of injector.

 

...

 

Fair enough.