'12 LS3 ID 850's Question

[Iam Broke]

Getting tired of fighting the FIC 72's at 4 bar. (60#/hr @ 3 bar) Questioned them on the data provided and although they say it is correct I had to rape the MAF over +20% to get the fueling in line. Commanded fuel pressure is ~67 psi at 9 lbs boost and it does drop to 60 at 6600 but that's not enough for the MAF rape. The positive skew is consistent through the mid to high boost range before the FP drops. IDC is peaking at 84% at .80 lambda on E35 so I believe they are 72# injectors at 4 bar but no way to tell here.

Posting from work so no log or tune but I was about 3-4% positive on the MAF cal vs stock with the K&N & SLP TVS on SLP's 52's before maxing the injectors out.

My question is will the ID 850's require a scale in the tune? Never did that before and iDK how complicated it becomes.

Thanks!

[Iam Broke]

Here's a screen shot at the top of 3rd. My biggest problem being OCD is that the torque and HP calcs in the ECU are ridiculous after skewing the MAF cal this much.

LS3 SC 4-13.jpg

[camarochevy1970]

ID provides you a lot of data for the cost of their injectors to help you with issues like what you are currently working on

http://www.injectordynamics.com/ApplicationData.html

[ScarabEpic22]

You will have to scale the tune with ID850s, but since the data is pretty close you wont have to rape the MAF to get fueling in line.

[Iam Broke]

Well, I read the scaling article on the ID site by Dsteck, lots to learn. I think the ID 725's are around 80 lb/hr at 4 bar so they are prob enough for my app and don't look like they need to be scaled from what I can tell of the tables. Decisions, decisions...

[DSteck]

You don't need to scale your PCM unless you run 2000s.



Expect to change the MAF. Don't expect to have trims be +20% here and -20% there. They'll fall in line.

[Iam Broke]

I understand about the LTFT's settling in, they did after a 40 mile cruise. The screencap I posted with the LTFT's -6 or so was only 7 miles into it once everything was good & warmed up.

I just didn't expect to have to rape the MAF from 60.x to 80.x lb/min in the 10,050 range with just an injector swap to get commanded PE. (Similar increases throughout the entire range)

I think the FIC 72# @ 4 bar data sux but FIC quit responding to my emails.

Glad to know I can put in 850's without a rescale. Thanks Dave.

[ScarabEpic22]

You don't need to scale your PCM unless you run 2000s.



Expect to change the MAF. Don't expect to have trims be +20% here and -20% there. They'll fall in line.

Guess it depends on the OS, I had to scale my 07 TBSS tune for my ID850s. I know the newer OSs have the higher IFR limit, a '12 should have the higher limit so no rescaling necessary.

[Iam Broke]

I loaded the ID850 data in a copy of a tune to play around and the IFR table maxes out at 127 iirc, but at pressures I'll never see. Ordering some 850's today. Thanks all.

[ZO6_Bryan]

You'll have to scale the MAF table but mostly only in the very low end and idle area from my experience with the ID850's.

[Iam Broke]

That's no biggie, I expect some trimming to be done. Thanks for the advice.

Dave, you have a pm.