2007 Corvette C6 Vert. A6
LME LS402, Pat G custom cam, ATI 10% OD Damper
Circle D triple disc 2600, 3.42 Diff
YSI, 3.0 pulley, ID 1000's
Alky Control Meth,
ARH 1 7/8 headers,
1009 RWHP @ 7000, 817 RWT @ 6000
https://www.facebook.com/tuningbyshanehinds
[email protected]
2009 G8 GT [email protected] 1.60 - Sold
2008 A6 LS3 C6 Cammed [email protected] 1.44 Sold
2013 CTSV wagon 9.21@151
2015 C7Z bolt ons 10.0
I could be the farthest from the diagnosis here, (never stopped me before) but it seems like this may be a mandatory pre-overdrive diagnostic cycle as it has to be repeated after a cool down, and for EVERY drive. I would wager a guess in this case that after a certain fluid temperature is reached, a calculation/comparison may be determined when engaging 4th to assure that there actually is in fact the expected 1 to 1 drive ratio, or some figure within tolerance. Now hopefully where that data is stored, (TCM, PCM?) and how to freeze it in there or bypass the diagnostic will be the next task driving you guys crazy.
Everything you are saying here makes sense, but it just doesn't seem to line up in my logs. I went back to a track day and compared the logs to the tune.
Each gear starts the shift at exactly the mph I have set in the tune... which corresponds to what you are saying. The problem comes because the when the shifts actually occur, doesn't match at all the rpm I set them for.
For example the 3/4 shift. Set at 30mph and 6300 rpm. The shift start at 30mph exactly but completes at 38mph / 6750rpm.
I then changed the RPM down to 5800 to try and get it to shift earlier. It triggered and shifted at the same spots again. It seems the rpm is not having any effect, which is what Chris (subfloor) has always said.
Getting it to trigger is easy, by mph, but getting it to actually shift where I want has been another story.
2007 Corvette C6 Vert. A6
LME LS402, Pat G custom cam, ATI 10% OD Damper
Circle D triple disc 2600, 3.42 Diff
YSI, 3.0 pulley, ID 1000's
Alky Control Meth,
ARH 1 7/8 headers,
1009 RWHP @ 7000, 817 RWT @ 6000
Let me catch up with you here. In the example you said 3/4 shift, but list speeds in the 30's. I'll assume you are actually talking about the 1/2 shift in your example.
Especially in 1st gear where things are happening fast, things have to be lead. Like I mentioned above, the preshift process takes time. If it starts at 30, and is not ready to strike until 38, then setting the rpm lower than what 38mph corresponds to isn't going to make it shift any earlier. Set the mph lower to like 20, then experiment with rpm changes. Especially in 1st gear with a high powered car both rpm and mph will have to be lead alot. I often set the mph to what 4000rpm would be so that it has plenty of time to get ready in preshift mode (only talking about 1st gear here). If you want it to shift @ 6300, you might have to actually set the rpm to 5600 or so to make it happen. If you watch what my trans program does, you'll see it leads all the mphs, more so in the lower gears. But it only leads the rpm in the lower gears when the lead setting starts to get cranked up. (rpm leads only show up when your ready to paste out from the export screen)
Now to throw a monkey wrench in here. Saying that rpm doesn't make a difference can actually be taking place. There are tables we don't have in HPT that show if the wot rpm qualifier will be used. Lot of stock cals don't use rpm for 1/2 - Almost all do for the 3/4. It's been this was since genIII stuff. Back then speed was the only thing used for 1/2 and then rpm was included in the later gears. The newer calibrations seem to follow the same pattern. When the rpm qualifier is not used, it follows the same process it does when not at WOT. As soon as the pre shift process is ready and complete, it just goes ahead and shifts. Clear as mud now?
Here is a screen shot from brand "C".
Rpm_Qualifier.JPG
Last edited by Bluecat; 02-23-2014 at 05:14 PM.
You are right. I was rushing earlier and meant to use the 3/4 shift but put numbers from the 1/2 .
The 3/4 is set to change at 88 , and does start the shift there.. The actual shift occurs at 97-98 mph. Again, changing rpms didn't have much effect. When set to 5800, it shifted at about 6600.
I have to play with it more when the snow melts, but I always have the same problem. It starts the shift where I want it to, but the completion is just not very consistent.
2007 Corvette C6 Vert. A6
LME LS402, Pat G custom cam, ATI 10% OD Damper
Circle D triple disc 2600, 3.42 Diff
YSI, 3.0 pulley, ID 1000's
Alky Control Meth,
ARH 1 7/8 headers,
1009 RWHP @ 7000, 817 RWT @ 6000
Just to add to this, I have experienced the same problem. I thought it was fixed with my most recent tune because it behaves well on the street, but my last trip to the track proved me wrong. I got the opportunity to hot lap after sitting for a while, and picked up the better part of 2mph and got my best pass ever. As a matter of fact, I made three passes in a row and got quicker each time.
2017 JKU Rubicon: Purple, long arms, tons, 40s, Banks CAI, Borla cat-back, TD2/HPT tuned, daily.
2017 GMC Sierra SLT: 6.2/ 8spd. Just getting started on it...
Bump - anyone figure out a way around this besides running through the gears in the burnout box or staging lanes ?
Once the weather clears up ill try to get it to happen again for me while logging.
What if I just disabled abuse mode? what negative impact would that have and would it help?