V2 program improvement suggestion

[Telco]

While working on my 2000 Silverado's trans tune, I had occasion to use the Speedometer Calculator's Shift Point Correction. I decided to use a Corvette's shift parameters for my truck as what I was using wasn't quite working right. If I had the same kind of trans I'd be spot on since it allows you to change the gear and tire sizes, but in my case I am using a trans with different ratios. The Corvette shifting program is working a lot better so far, but it's not quite perfect and I suspect it's because the trans ratios are just far enough off. Thanks.

[joecar]

Watch out for the Corvette shift parameters, it has Transaxle checkmarked in the Speedo calculator whereas the Silverado should not have that checkmarked.

[Telco]

I just used the program to calculate the numbers, I didn't do a segment copy. I then copied over the specific fields I wanted. I also unchecked the transaxle box when I did the calculations. The thing was the Vette was using the same gears as a 4L60E where I am using a 4L80E with a TCI low gear set. What's in there now is working pretty well but later on I'll sit down and work out what adjustments need to be made to account for the gearing differences. Thanks for thinking of the potential problem though, I'd rather have found out now than from the trans rebuilder. :grin:

[joecar]

In the Transmission segment there is a table for gear ratios, you can edit the TCI ratios into these.

[Telco]

Yes, but that wasn't what I was aiming at here. I verified those fields were in place before ordering the 4L80E and those fields are correct for the trans in my program. And, the 2.75 first/1.57 second make my 4L80E feel a lot like my 4L60E in shifting except with the 4L60E I could easily break the rear tires loose due to the 3.01 first gear and the 4L80E won't. The tires would be at the verge of spinning with the low gear 4L80E. It was well worth the extra expense IMO.

The change I was looking at would allow you to adjust the shift parameters in the Speedometer Calculator's Shift Point Correction so if you were to do as I did and change transmission types, and your old transmission were dialed in and shifting perfectly, you would be able to use the Speedometer Calculator's Shift Point Correction to adjust the shift points for the different gear ratios in the new transmission. You'd then be able to copy and paste those fields to the new transmission's program and have your shift points at the same place as the old transmission.

[joecar]

Ah, I see :cheers: