floman

iTrader: (54)

I have a 98 SS with a L92 swap with cam & bolt-ons and Moser 12 bolt with 4.11 gears. Just finished up swapping in a 4L85E & FTI converter replacing the old 4L60E/Circle D conv.

I have HP-Tuners and not much experience using it until a week ago on this swap. I am using the 4L60E tune that was working in the car previous to this swap. I used the "slow67" relay mod to allow the 98 PCM to control the new 4L85E.

I have basically scaled up the WOT & Part throttle shift tables 19% in 1st-2nd gear shifts, and up 9% on the 2nd-3rd gear shifts. I based this on the calculated differences between the 1st and 2nd gear ratios of the two transmissions. I left the shift RPMs at 6500 rpm where they were set as my desired shift point.

Took the car to the track today to make a couple of passes to see how the tranny performed. Everything went well, tranny performed great. BUT, my shift points are still too low. Shifted out on 1st-2nd at 5700 rpms, 2nd-3rd at 6200 rpms. Re-flashed another tune with the shift tables bumped up another 2 mph and still shifting about the same , 5700 & 6200 rpms.

Question: Do I just need to keep raising the mph in the tables until it shifts at my desired 6500 rpms in each gear change? I don't want to make too big of a change and not have it make the upshifts.

Any suggestions, or does anybody have any shift tables that might be a good reference for me to look at?

Thanks in advance

mrvedit

Did you update both the partial throttle and WOT shift tables? I have changed trans gear ratios and that was all it took.

floman

iTrader: (54)

Yes sir, I did change the values in both sets of tables. I put the same mph settings in the part throttle tables in the last two cells on the "normal", "cruise" and "hot" tables.

I added 19% to the 1st-2nd shift, and 9% to the 2nd-3rd shift which is not much really on the WOT and 100% TPS cells its only about 4 mph. I think I'm at 29 mph on the 1st-2nd shift and 54 mph on the 2nd-3rd shift. To me that seems really far from what the actual mph would be when those shifts are made. By using a calculator and doing the math with 4.11 rear gears and 28" tire my 1st gear of (2.48) should be 53 mph without any slippage factored in, and 2nd gear (1.48) should be around 89 mph with no slippage.

I was just watching my tachometer at the track to see my shift rpms, surely its not off that far ( with the 4L60E it would shift each gear right at 6500 rpm). I need to learn how to set up my data logging to record the actual speeds and rpms of the shift points.

I guess I can just keep bumping the MPHs up, I did re-flash another tune at the track with the MPHs bumped an additional 2 mph on each shift, but it didn't seem to change anything. I just didn't want to make too big of changes at one time. I'm still very new to the tuning thing and don't want to hurt my new $3000.00 transmission ( also known as my *** pocket) hehe.