Pontiac Grand Prix Forums : Grandprix

I have a question about shiftpoints. In the tranny section using a DHP PT, you have the Performance shift WOT MPH section and RPM section.

Say I want to shift at 6400rpm, but don't know what mph that would be...how do you adjust for this? I think it is around 93mph in 2nd gear with 3.29's, but does it look at the RPM WOT shift point or the MPH?

Also in the performance shift TPS %, I'm assuming the 100% should be the same mph as the WOT mph...

Just a little confusing. Any help would be great. Thanks!

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

At WOT, the PCM uses the RPM shift points. At less than WOT, the PCM uses the MPH shift points.

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Morad Parts Company

1997 GTP - 200k+ miles, PEMs, 3" SS Exhaust w/ Borla Mufflers, 3.4", 180* stat(summer), FWI, 1.84 RR, PT, SLP hood, KYB GR2s, GMPP Handling Kit, etc...

Awesome. That makes it pretty easy. So I can now just scan and start with the WOT RPM shift point first and adjust the MPH after the scan to get it close.

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

It has been mentioned before, but as I it understood both conditions have to be met. Here is a shift verus MPH based on gearing spreadsheet from Jim at easyperformance...This was pretty close based on the tune Trannyman did. Scanning confirmed as does the tables in the PCM.

Attached Files

Shift_Points_for_Grand_Prix_4T65E_Transmission.zip (9.2 KB, 34 views)

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04 Indy SS build #972
GPS Cam 1, TOG's, Tripleedgeperformance.com transmission-ported blower-build and tuning, PRJ wires, PRJ Rails, Stage 2 IC.

That is an awesome graph. Now if I put the gearing for 1st 2nd 3rd 4th in the RPM 1, 2, 3, 4 spaces, will it switch the table for me?

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

I just answered my own question. THAT IS AWESOME!

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

Ok...I have 1 more question after messing around with the table.

You can change the individual gear ratios for 1st 2nd 3rd and 4th. But the final drive ratio is 2.93 still. When we change to 3.29's we just change the drive and driven gears and not the individual gears. How do you change the final drive ratio change to implement the change across all the gears?

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

:Nevermind...at the bottom of the spreadsheet, there are tabs for all 3 gear ratios!

Thanks a million for this!

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

One more thing to consider.....there is a small time laps in when the PCM triggers a shift and the shift actually happens, My general rule of thumb is 300rpm......to explain, if you want the shift to happen at 6700, put in the table 6400. When in 1st gear and at WOT, if you have it set to 6700, by the time the tranny actually shifts and gets your RPM's back down you could be at 7000 and thats not good....just give yourself a little buffer.

webracin

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2001 Grand Prix GTP
ZZP HUB 3.2 3.4, ZZP 8 Rib conversion, JC 3" DP Gen 2 cat & U-bend Delete, Accel Super Stock 8mm wires, DHP 1.5, 180* Thermo, Throttle Spacer, SS Intercooler, ZZP Fuel Rails, SLP CAI w/K&N Cone, Dynomax cat back, ZZP Tranny.

2000 Grand Prix GTP Daytona K&N, Flowmasters

Yeah...for sure

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

I compared my tables to the sheet for 3.29's and my 1st WOT shift rpm and mph don't match, but the 2nd shift rpm and mph do match. Is this the cause why I have a kinda strange 1-2 shift? (sorry to hijack)

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1997.5 Regal GSX13.9@98.72-6K HID, Pacesetters,P+P blower,SLP catback,tinted tails,CompG suspension,72mm TB,Thrasher shift kit/Intake,PT,3.29's
70 Monte Carlo SS454 12.5@109 full roller gen VI big block,480hp/550tq.

How far off are you, from the table? I'm sure that the spreadsheet is a close approximation.

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04 Indy SS build #972
GPS Cam 1, TOG's, Tripleedgeperformance.com transmission-ported blower-build and tuning, PRJ wires, PRJ Rails, Stage 2 IC.

I've got my 1-2 shift (at WOT) 5700 rpm and 39 mph. The spread sheet says at 5700 rpm I should be at 42.75? I get a shift, then not even a half sec. later it will shift real hard...sometimes chirp. (The chirp is mainly due to my winter tires being only 15's and real narrow I'm guessing)

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1997.5 Regal GSX13.9@98.72-6K HID, Pacesetters,P+P blower,SLP catback,tinted tails,CompG suspension,72mm TB,Thrasher shift kit/Intake,PT,3.29's
70 Monte Carlo SS454 12.5@109 full roller gen VI big block,480hp/550tq.

I would put the MPH closer to what the table says and then scan to get it closer.

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Jae Harris: XPZ, 1.6 RR's, 2.8-2.6 DUB, Stage 4 Gen III, P&P LIM, N*, LQ4, FWI, Stg 3 Heads, ZZP Stg 3 IC , 42.5lb, SLP Headers, 2.5"SLP Catback, Cutsom Tranny w/hard parts, 3.29's, 2800stall, ICCU, LS1M, GMPP Susp, BMR F/R Sways, Next LVL STB, F-boby Brakes

I'll give it a try

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1997.5 Regal GSX13.9@98.72-6K HID, Pacesetters,P+P blower,SLP catback,tinted tails,CompG suspension,72mm TB,Thrasher shift kit/Intake,PT,3.29's
70 Monte Carlo SS454 12.5@109 full roller gen VI big block,480hp/550tq.