Now that I have my other issues resolved I'd like to start fine tunning this thing. As far as the transmission goes,what can I expect from tunning without a shift kit? IE; could I get it to chrip the tires from 1-2 gear? I've read alot online but would like to know if someone has experience with it. Also, in tunercat, what do the "Manual up/down shift points" do? Mine are set really low but I can hold it in 1st until it reaches the limit I set in the constants table. Is this normal?

Thanks
Brian

 

Brian, here is some transmission tuning info ref Solomon's site, look about 2/3 the way down the page http://www.lt1pcmtuning.com/tips/ . The PCM uses the Manual up/dn table to control the tranny whenever the shift selection is not in "D" . The stock settings usually force an upshift prior to max RPM setting. Lots of tuners set the settings to something you never hit EG: 220 up / 215 dn to disable PCM control of shifting in manual operation. Specifically if you are doing a dyno run in 3rd you don't want it up shifting to 4th . If you want to keep PCM control of manual up/dn shifting make sure the RPM matches the rear and tire size setup you have on the '69 setup. Your stock '94 A4 tune was most likely set for 2.73 rear so you settings on all your tables (normal, manual, cruise, kickdown, performance (FB T/A only) need to be adjusted to your 3.36 rear. Depending on your tires, your 3.36 rear, chassis setup & weight of the '69 body your stock engine (275 FW/HP) should defiantly chirp in 1st and possibly 2nd with correct engine and tranny tune.

 

Cool, thanks. Another piece to the tunning puzzle.

Brian

 

This isn't making any sense to me. If I understand what are saying, If I put the selector in say 2, then it should follow the manual up/down shift points? Becasue this isn't working for me. I have the manual 1>2 upshift set at 20 mph from 0-18.8 TPS% but the trans shifts at 11 mph which is what I have the normal shift point at. In my 94 Corvette shop book, in the 4L60E component malfunction tables, it lists a "Manual switch" v-8 Pontiac F-car only and also the "Performance Switch" v-8 Pontiac F-car only. But, I cannot find any reference to this manual switch mode in the wiring diagrams only the performance mode. It's not really a big deal I guess, but it seems to me something must activate the manual mode, not just the gear select.

Brian

 

Manual mode tables have no effect on my Y-body.

Might be an F-only thing...

 

Ok, I figured it out. Found an old post that talked abot this. Manual mode only works in D2,D1. In the tunercat switch table, must have "Force Manual Mode in D2" enabled. I checked that box and it seems to be following the Manual mode shift points.

Brian