'91 #473 Tuning

[jss06c6]

Gents,

Spend most of my time on CorvetteForum (don't hit me!).. Just getting old and habits are hard to break.

Finally put #473 on the rollers a couple of weeks ago. With SW Headers, full SW exhaust, Hi-Flo cats, Fidanza FW, Delphi Injectors and Marc's tune, the car put down 345 rwhp and 349 rwtq. Hot engine (drove to dyno shop) and an 80 degree day. Talked to Marc and we figure we're missing about 16 hp. Past runs (before exhaust upgrades) put the AFR at 11.9. Didn't have a tailpipe sniffer this time, so not sure what it showed, but worthless anyway since I'm running metal matrix cats. Decided to do my own tuning.. Very comfortable with LS platform and HpTuners, but not OBDI. Thanks to Dominic's counsel, I now have TunerPro RT V5, Moate's APU 1 and a new AEM wideband O2 sensor to install. I suspect the Low

I located a stock BIN on GearHead-EFI along with a BIN definition file to read it. With help from Dave Blundell at Moate's tech support, I finally got the current tune downloaded. I want to duplicate it on another SST 27SF512 chip so that I don't run the risk of messing up the tune that I got from Marc (will leave this chip "unmolested").

Now that I can interpret BIN files, I'll get the wideband O2 sensor installed and begin to log data so I can see how the tune sits here in Texas. Car runs great (of course! Marc's tunes are legendary), but I can't resist the temptation to tune I really enjoyed dialing in the VE tables and spark along with other tweaks on my LS2, so looking forward to learning OBDI secrets. I'll share what I learn so that others can take advantage of my wins and headaches!

My ECM is a 1228331 with a broadcast code of AXFK. I'm using the stock BIN from GearHead-EFI along with the BIN definition file from GearHead-EFI.

AXFK_91_Vette_5_7DOHC.bin

$AF 91 Vette ZR1 LT5.xdf

Both of these are on the GH site (most complete set of BIN files and BIN Definintion files I have seen on the web!) Incredible resource!

My custom tune uses a $AFA Bin definition file.

There are some location differences for equivalent parameters between the two BIN files, so at this point, I can't see how to use a common *.xdf to easily do comparisons, but not worried, since I'm going to create a copy of the current tune on a new SST27SF512 chip using the $AFA definition file and then create a copy of the stock BIN file using the $AFA definition file. Then can do comparisons using TunerPro RT.

So, stay tuned and I'll keep everyone posted as I translate my LS tuning knowledge to the OBDI environment and TunerPro RT.

[XfireZ51]

Steve,

Shouldn't be any real difference between the AXFK ($AF)calibration and
the BRXB ($AFA). The main parts should be identical. GM added a couple of lines of code, but didn't change much else between the two versions of the cal.
IOW, you should be able to start w the BRXB cal without worrying about "converting" the AXFK to the $AFA Mask.

[jss06c6]

Good idea, I'll give that a try!

Thanks..

Sent from my XT1585 using ZR-1 Net Registry mobile app

[-=Jeff=-]

Don't forget the ADX file for data logging


Sent from my iPhone using ZR-1 Net Registry

[jss06c6]

Yep, I've got it already.

Mainly interested in how the AFR looks and the VE tables..

Sent from my XT1585 using ZR-1 Net Registry mobile app

[MickeyD]

Originally Posted by jss06c6

Yep, I've got it already.

Mainly interested in how the AFR looks and the VE tables..

Sent from my XT1585 using ZR-1 Net Registry mobile app

Hey, do I know you! Glad you came over to the dark side. David and I are trying to plan a drive over in Southwest Section. Just started convo.

[jss06c6]

Mike,

Let me know when you get it planned. Just got the wideband installed. Now ready to start getting the VE tables dialed in.

Steve

Sent from my XT1585 using ZR-1 Net Registry mobile app

[jss06c6]

AEM Install.. all working well.. Logging data next step.

[MickeyD]

Originally Posted by jss06c6

AEM Install.. all working well.. Logging data next step.

I have no idea what you are doing will do! I need help just to change my oil and that's coming up. Kudos to ya Steve. I am just not mechanically inclined. Do you charge by the hour?

[XfireZ51]

Originally Posted by jss06c6

AEM Install.. all working well.. Logging data next step.

Steve,

What r u using as a datalogger? How r u connecting to the ALDL?