tuning help needed. no manual shift at wot
12-28-2006, 10:24 AM
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tuning help needed. no manual shift at wot 99 f body 4l60e. i noticed that my car will not manually shift at wot. it hits the rev limiter on the 1-2 shift if you move the shifter up to second when it is time to shift. i suspect it has something to do with my pcm tuning since my rear gear was changed from 2.73 to 3.73. a friend recalibrated the speedometer with his flash software but did not change any of the shift settings. the trans shifts great in the overdrive and drive position and will manual shift at part throttle. i hoped that maybe someone else has run into this before and could tell me how they corrected it.
12-28-2006, 10:45 AM
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i was thinking on the same lines but i'm not sure quite where to start. i figured the shift mph would be off since the gear was changed but im not sure why it only affected the manual shift. i will have hp tuners soon and im looking for some insight on where start correcting this. is there seperate tables for manual shift settings and overdrive settings. thanks for your help
12-28-2006, 11:21 AM
#4
In order to shift manually like you're trying to do (not sure why you want to, the pcm shifts faster than you can), you need to install a shift kit that will allow you to hold any gear manually (transgo HD2 for example.)....In stock form, you can't manually shift a 4l60e like you're trying to do, no matter what you change in the tune.
12-28-2006, 11:48 AM
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the reason i want to hold it in 1st gear is when the car is spinning i need to pedal the car some. when i pedal it it shifts to second. once it stops spinning, i go back wot and it downshifts back to 1st. then is starts spinning real bad. to further elaborate on my shifting problem, even when you move the shifter up to second gear at 5000 rpm it still bangs the rev limiter. the only way for me to avoid the rev limiter is to make the whole pass in drive or overdrive, which isn't possible for my current combination. furthermore a friend has another f body, same year that will manually shift at the shift point just fine. same rear gear, same trans builder, same internal trans modifications. the only difference is his has a hypertech programmer to calibrate the rear gear change with. that is the reason i am looking for some tuning advise.
