WOT Transmission Troubles
07-14-2004, 09:53 AM
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WOT Transmission Troubles First a little bit about the car - 99 Z-28 Camaro with a cam, 2800 or 3200 converter, and a TransGo shift kit and 4.10 Gears all put in by the owner of the car.
When I got the car it had Hypertech Programming in it which I removed and then started to tune it with HP Tuners. Changed the Idle speed up to get it to idle with the cam and changed the Speedometer setings using 4.10 for gear and the same tire size since that didn't change. Put the car on the dyno to see where it was at before tuning A/F and timing, the car made one good pull and on the next pull and every time after that on the dyno or on the street this is what happens at 95-100% throttle:
Gear selector in OD
Shifts ok 1-2
2-3 Car seems to bonce of rev limiter 2-3 times before shifting
Gear Selector in D
Shifts so so 1-2 hits limiter once?
2-3 Car seems to bonce of rev limiter 2-3 times before shifting
Gear Selector in 2
1-2 Shift seems to sit on the limiter and then shifts
Also the speedometer seems to be off by twice as much speed.
Read suggestions here about the MPH tables and shift times, so I fixed all of the MPH shift tables as well as moved the Shift RPM down. I also lovered teh shift time down to 0.15 and tried fixing the speedometer by using numbers that were posted for a certain gear/tire and converting them for my application. Car still behaves the same way except on the street I noticed that if the selecter was in D or 2 (esp. 2) giving it light throttle (1/8 to 1/4) it will go way up in the rpms and then shift hard, real hard like a WOT shift. Adjusted MPH more and the TQ Management tables all to no avail and the only way I could get the speedometer correct was to multiply the values by 1.50 and enter them.
My question now is can this shifting be caused by the ECM or is it something in the transmission like something wrong with the Transgo Kit or converter?
Are the speedometer settings way off and causing this behavior?
Are my changes to the shift tables too much or too little?
Is there a way to test just the transmission without the computer control?
I can't verify how it drove before I put the first program in, I only drove it from the parking lot on to the dyno. I also can't vouch for the install of the components since I didn't do it and the owner who put the parts on forgot to put the o-ring on the new oil pump when he put it on.
Any help, thoughts or suggestions are welcome
Thanks,
Greg
When I got the car it had Hypertech Programming in it which I removed and then started to tune it with HP Tuners. Changed the Idle speed up to get it to idle with the cam and changed the Speedometer setings using 4.10 for gear and the same tire size since that didn't change. Put the car on the dyno to see where it was at before tuning A/F and timing, the car made one good pull and on the next pull and every time after that on the dyno or on the street this is what happens at 95-100% throttle:
Gear selector in OD
Shifts ok 1-2
2-3 Car seems to bonce of rev limiter 2-3 times before shifting
Gear Selector in D
Shifts so so 1-2 hits limiter once?
2-3 Car seems to bonce of rev limiter 2-3 times before shifting
Gear Selector in 2
1-2 Shift seems to sit on the limiter and then shifts
Also the speedometer seems to be off by twice as much speed.
Read suggestions here about the MPH tables and shift times, so I fixed all of the MPH shift tables as well as moved the Shift RPM down. I also lovered teh shift time down to 0.15 and tried fixing the speedometer by using numbers that were posted for a certain gear/tire and converting them for my application. Car still behaves the same way except on the street I noticed that if the selecter was in D or 2 (esp. 2) giving it light throttle (1/8 to 1/4) it will go way up in the rpms and then shift hard, real hard like a WOT shift. Adjusted MPH more and the TQ Management tables all to no avail and the only way I could get the speedometer correct was to multiply the values by 1.50 and enter them.
My question now is can this shifting be caused by the ECM or is it something in the transmission like something wrong with the Transgo Kit or converter?
Are the speedometer settings way off and causing this behavior?
Are my changes to the shift tables too much or too little?
Is there a way to test just the transmission without the computer control?
I can't verify how it drove before I put the first program in, I only drove it from the parking lot on to the dyno. I also can't vouch for the install of the components since I didn't do it and the owner who put the parts on forgot to put the o-ring on the new oil pump when he put it on.
Any help, thoughts or suggestions are welcome
Thanks,
Greg
