Missed 2-3 shift...Log enclosed from track

[exploder]

I have a log here from the track. The car was moving out pretty well, but the car didn't make the 2-3 shift in time and banged the limiter. I had to let out and then get back in it...I still ran a 10.3 at 136. I am going to enclose a log a tune from prior to that run and then another tune with what I changed to try and correct it. I never got a chance to test it to see if it worked or not, tell me if I went the right way or if I need to go more. Thanks

[joecar]

I looked at your files briefly, I am going to look in more detail.

[jfpilla]

You have the 1-2 shift set at 40mph. The corresponding 2-3 shift mph is 75mph.(you're set at 85mph) It's never a perfect correlation, but when you find the mph that causes shifts at the rpms you've set then you can set your rpms with more confidence.

[Slowrc]

You have the 1-2 shift set at 40mph. The corresponding 2-3 shift mph is 75mph.(you're set at 85mph) It's never a perfect correlation, but when you find the mph that causes shifts at the rpms you've set then you can set your rpms with more confidence.

What math dictates this?

My Z shifts to 3rd @ 6200 and I have it commanded @5800. I had to back it down to 5800 to keep it off the limiter????? I don't know why either...

[jfpilla]

What math dictates this?

My Z shifts to 3rd @ 6200 and I have it commanded @5800. I had to back it down to 5800 to keep it off the limiter????? I don't know why either...

There may be some formula for it, but I doubt that there is a simple one.
The popular theory is that both the MPH and RPM parameters must be met for a shift to occur. Faster reving cars and/or slow shifting trannys need to have lower MPH settings relative to the desired RPMs.
ex:On my current setup with a fast shifting RPM trans I have the MPH in 1st set at 50MPH and 6750RPMs. It shifts at 6900RPMs. That was based on my first trip to the track, with this setup, where I had 1st set at 40MPH and 6750RPMs and it shifted at 6000RPMs. I had set the MPH low based on my experience with my previous setup.What MPH to set? It seems to be just trial and error.

[Slowrc]

There has to be some better info on this. I thought the mph was an enabler "something that must be met for the shift to happen" and the rpm was the point that it happens. Thats what it looks like on my logs. The current gear pid swithes from 2 to 3 right at 5800 as I command , But the rpms top out at 6200 on the log. This may be more normal than I think...Maybe between TM, high stall, and high rpm thats as quick as the trnny can get it done.

Disclaimer: These are my thoughts and assumptions

[joecar]

The WOT shift parameters are still a mystery as far as blowing a shift, and a stall makes it worse...

there might be some tables/parameters that have not been discovered yet.

[joecar]

Whether the MPH is the enabler and the RPM is the trigger, or vice-versa, it doesn't matter since observing this shows that the shift happens after both conditions are met regardless of their order (or, rather, this is what I have observed, which doesn't make it universal... "don't assume anything").

[joecar]

exploder,

Your 0005 and 0006 tune files only differ in the PE table... or am I looking at the wrong files...?

Cheers
Joe

[Slowrc]

Whether the MPH is the enabler and the RPM is the trigger, or vice-versa, it doesn't matter since observing this shows that the shift happens after both conditions are met regardless of their order (or, rather, this is what I have observed, which doesn't make it universal... "don't assume anything").

Good to know