Help with gear change
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Teching In
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Help with gear change I have a 2000 Firebird with the 4L60E auto. I want to change the rear gearing to a taller gear from the stock 3.23 I read the FAQ about gearing and it was useful, but I still have a question for any of those that have done this on their 4th gen F-body. How and what did you do/use to change the values in your PCM for speed (mph) change, converter lock-up, shift points...etc Any and all help would be greatly appreciated.
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From: Schiller Park, ILL Member: #317
It doesn't have to be HP tuners specifically, it could be any tuning software. Even a basic HPPIII handheld could make the necessary shift point and speedometer recalibrations.
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Teching In
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Thanks guys, I have never used a HP tuner or any other tuner, Do they come pre-programed for what I want to do? I read up on the Hypertec one last night and it doesn't do gear ratios just tire size? Any suggestions of which one to use for a newbie?
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From: Schiller Park, ILL Member: #317
Hypertech (HPPIII) does, in fact, also do speedometer and shift point corrections for gear ratio changes. Or, at least it always did historically - I haven't checked current production in quite some time but I can't imagine why they would have changed it. I can tell you first hand that the older ones 100% certainly offered this feature.
But there are a bunch of tuning options depending on your overall goals, budget and skill level. You can also just get a mail order tune to fix basic stuff like gear changes.
But there are a bunch of tuning options depending on your overall goals, budget and skill level. You can also just get a mail order tune to fix basic stuff like gear changes.
The HPP3 handheld I have for my '98 does have adjustments for both rear gear ratio and tire size. I dusted it off after sitting in the closet for 20 years to use when I swapped to an S60 / 3.73 ratio (I didn't change tires so didn't need that feature, but saw it in there). NOTE that the gear ratio selections seem to be limited to what gear ratios are available for the OEM 7.5" 10-bolt (its not an infinitely-variable adjustment...... unless there is an "other" selection that allows user input of the ratio that I didn't see).
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Verdad Gallardo Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Looks like the Hypertech tuners have been updated a bit since mine was made back in the early '00s. Here is what they currently offer for a 2000 V8 Firebird:
https://www.hypertech.com/vehicle-re...x?AAIAID=27161
The "Speedometer Calibrator - Part #732500" says the following regarding gear ratio changes:
Gears 2.73, 3.08, 3.23, 3.42, 3.73 & 4.10
It would probably be more cost effective to just get a mail-order tune from a shop that does these cars. Then you could get some other basic stuff updated for the same price (if desired).
https://www.hypertech.com/vehicle-re...x?AAIAID=27161
The "Speedometer Calibrator - Part #732500" says the following regarding gear ratio changes:
Gears 2.73, 3.08, 3.23, 3.42, 3.73 & 4.10
It would probably be more cost effective to just get a mail-order tune from a shop that does these cars. Then you could get some other basic stuff updated for the same price (if desired).
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
Custom tuning (even mail order) can be done for any ratio, as far as I know. Lots of folks with 8.8 & 9" rears using various Ford gear ratios and they've all been able to get a tune for it.