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98 ECU 3->4 shift speed

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Old Sep 22, 2015 | 09:14 PM
  #1  
kylush's Avatar
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From: Watertown, SD
Default 98 ECU 3->4 shift speed

I recently changed my rear gear ratio to 3.73 from the stock 2.73 ring and pinion. I love the new gears but when I went into the speedo tab of hpt and recalibrated my speedo I used the auto scale trans table option and coupled with the shift extension from my 3600 stall my shift points aren't quite right. If I go WOT I will bang off the limiter at the top of 2nd. Now I read the sticky and every thing makes sense and looking at my hpt file everything makes sense except for one thing. My 3 to 4 shift mph is set to like 192 mph. Looking at the stock tune it was previously set to 255 mph. Should this be reduced to something more realistic? How the heck did it even shift into 4th at WOT before when it never saw that mph?
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Old Sep 23, 2015 | 12:15 PM
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just went and checked my stock 98 tune and it is set at 125 3>4 but it has 323's
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Old Sep 23, 2015 | 12:25 PM
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Originally Posted by kylush
I recently changed my rear gear ratio to 3.73 from the stock 2.73 ring and pinion. I love the new gears but when I went into the speedo tab of hpt and recalibrated my speedo I used the auto scale trans table option and coupled with the shift extension from my 3600 stall my shift points aren't quite right. If I go WOT I will bang off the limiter at the top of 2nd. Now I read the sticky and every thing makes sense and looking at my hpt file everything makes sense except for one thing. My 3 to 4 shift mph is set to like 192 mph. Looking at the stock tune it was previously set to 255 mph. Should this be reduced to something more realistic? How the heck did it even shift into 4th at WOT before when it never saw that mph?
Its set that way so it doesnt shift into 4th while WOT. 192 or 255 doesnt matter, you wont hit either one in 3rd gear WOT.
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Old Sep 24, 2015 | 12:36 PM
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So it's there to protect the trans basically since it's generally a bad idea to shift into O.D. at WOT. That's basically what I thought. I just noticed that in the sticky it had been adjusted down to a speed that actually could be hit in 3rd gear. Would this ever be a good idea? Maybe with a built transmission?
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