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Discussion Starter #1
how come you need a chip to change youre gearing? the tech article says something about the computer not being able to do its N over V deal but what kind of problems would that solve. seems like guys with fox bodys and the old eec IV swap from 2.73s to 4.10s without any computer work at all. no chip or nothin.

ive got 3.08s in my cougars open rear and i want to buy a used pumpkin with trak loc and at least 3.73s to move this boat. what kind of problems would i run into if i just threw them in along with a new speedo gear and went without the chip. i never heard of gear swapping requiring a chip...is it something with the newer eec V computer?

just curious, depending on the answer i may have to settle for some 3.27s....:(

any input is greatly appreciated.

-josh-
 

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I could be wrong.. but..

I believe it depends on the transmission. But basically the 4r70w is electronically controller, where as the AOD/AODE is hydraulic. The reason for the programming is that the computer needs to compensate for the fill up time since the new gears will rev faster than the older gears. So if the tranmission isn't told to start filling soon eough you will rev up and then bounce off the limiter, then it will shift, since the cylinder won't be full when it should be.

The computer can compensate for 2 gear steps. So if you have 3.27s then you can jump up to 3.73 without any problems. But 3.08 to 3.73 would require modification in the computer.

Again, this is the story I'm told for the 4r70w, I don't know about the AOD/AODE.
 

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Well, besides that, you just described it will screw up your shift schedule, this is true, but also, our vehicles use a driveshaft speed sensor to regulate top speed, and if you put 4.10's in your car, your top speed would probably be somewhere around 70mph or so, because at that speed, your driveshaft is spinning the same as It used to without the gears at 105.
 

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Discussion Starter #5
so the best thing would be to get a set of 3.27s then? or do you think i could get away with 3.55s?
 

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wigglesrewind said:
so the best thing would be to get a set of 3.27s then? or do you think i could get away with 3.55s?

Ive got some 3.55s.....for sale..pm me if you want them


joseph
 

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Discussion Starter #8
thanks for all the responses guys, i know how big these tanks are...my 89 is an absolute dog with that 3.8. i need as much torque multiplication as i can get out of this rear so the more gear the better!

-josh-
 
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