I finally put the O2 sensor in the exhaust today for the wideband, and saw what my readings were.
Holy crap I'm burning waaaaaaaaaay too much gas!!! At idle and off boost it's all hunky dory, but in boost it goes to somewhere BELOW 10:1, the gauge only goes as low as 10.0. Chris and I have a few hours to spend with a laptop haha. I was leaning towards some SS 36#ers but I think I'll hold off for a while. Some may remember my dyno sheet saying my A/F was way too lean, something above 18:1, well that's clearly not the case here.
I'll update when some tuning is done.
14.330 @ 96.37mph
have someone follow behind you when youre in boost, lotsa black smoke?
is the wideband calibrated?
what kind is it?
LE61T PTE6262 Powered 
AEM, UEGO. Calibrated, yes, as far as I know...unless I'm unaware of a calibration process. I know of the dial on the back of the gauge which is set to the proper position. Anything I'm missing here?
14.330 @ 96.37mph
Was the wideband installed correctly? IIRC if its not installed properly it could lead to inaccurate readings. dont quote me on that though im not positive.
If its all done right then playing with the laptop is a good idea.
I want to share something with you - the three sentences that will get you through life. Number one, 'cover for me', Number two, 'oh, good idea, boss', Number three, 'it was like that when I got here.'
I remember your dyno readings. Have you changed anything since then? I would consider trying to find someone in your area with a wideband as well. Maybe swap out and try. Only because you had 1 wudeband say lean and now 1 saying way rich. If you are running that rich you should smell it and see it. What has your gas mileage been?
FU Tuning
I agree with John... I'd be a little hesitant to start taking fuel out...
LE61T PTE6262 Powered
His car for as long as it's ever had the charger pours out black smoke under WOT... which is what confused us about the readings at the dyno.
Please keep in mind the dyno reading was from a tailpipe sniffer. We didn't want to add or subtract fuel until he had a proper wideband in there to see.
At idle it's reading 14.5 - 15.0 so... it's fairly accurate.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
SweetnessGT wrote:His car for as long as it's ever had the charger pours out black smoke under WOT... which is what confused us about the readings at the dyno.
Please keep in mind the dyno reading was from a tailpipe sniffer. We didn't want to add or subtract fuel until he had a proper wideband in there to see.
At idle it's reading 14.5 - 15.0 so... it's fairly accurate.
-Chris-
With that info then I would be ok with taking fuel out. It should add some power with taking fuel out.
Edited 1 time(s). Last edited Sunday, March 11, 2007 9:47 AM
FU Tuning
I think its really important to make sure these things are calibrated and to take out the 02 sensor when doing so. I dont think the tail pipe sniffer would make a difference of 18:1 to 10:1. At idle my car is 9.6:1 (really really bad), in boost I get 12-13. I thought you had a wideband in your car...since you always thought my car was going to blow up.
The difference is Sam, my computer was controlling injectors of which it knew the size of, my computer was reading boost properly. The gauge doesn't need to be calibrated, it just needs to be tuned. If I had stayed with stock reflash programming I wouldn't have needed a wideband, hence my delaying it's purchase for this long. I felt safe because of what I mentioned above. The machine used at they dyno place was clearly and obviously not functioning properly.
14.330 @ 96.37mph
Quick update. Chris and I did some tuning tonight and took care of that uber-fat mixture problem. It's now hitting a mid-to-high 11 throughout most of the rev range. Doesn't appear the injectors will need to be upgraded, the duty cycle hit a mid-80% at the most, on like one occasion. Still a few tweaks to take care of here and there but we got a damn good start on it tonight.
14.330 @ 96.37mph
Yeah a good few hours of tuning helped it quite a bit thus far. Many thanks to ROn for his advice and his histograms to get this done...
It seems the PCM tells the injectors to go well below 10:1 under boosting conditions, which is completely ridiculous. I had to pull out gobs of fuel in the mid range and then work with the IPW multiplier on the fueling tab to take care of the richness in boost.
We're seeing some knock while using the stock GMSC timing charts, (I've been seeing this knock since day 1 on his car) and I do believe it to be false knock so I'll look into that next time I sit down in the car. Timing is up next.
So - with all that said, I do believe the GMSC reflash just runs far far far too rich. Bill has a smaller pulley, larger crank pulley, and all kinds of breathing mods as well as secret cams and it was STILL pig rich, so... I donno whatsup with that.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Nice to hear that the issues are slowly being fixed up for you Bill. I so cant wait for my tuning session this friday and next week. Should be interesting to see what the car is running and how bad the ARF ratio is.
Did you put that larger pulley on my crank when I wasn't looking, Chris? I don't remember ever installing one!
14.330 @ 96.37mph
this makes me wish my car was tuned at the very least...for some reason, I would love to get chased by Bill at the track
I'm surprised more people haven't had any comments, be it from their own experience or as a way of saying thanks for giving them an idea what's going on with the reflash if they haven't gotten any HPT work done.
Next step in the process is getting the M45 back to it's previous boost levels.
14.330 @ 96.37mph
