Explain resetting shift points to me, please
Thread Starter
Tech Contributor
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Race Director
Joined: Oct 2002
Posts: 16,477
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From: Gone
CI 6-7-8-9-10 Veteran
St. Jude Donor '03
Using something like the Hypertech, it will simply alter all the shift points just based on the gear ratio data you enter. Pretty easy way to make the conversion you need done, but that's about the extent of the control you have over it.
Using more complex tuning software like EFI Live or HP Tuners (or having a pro tune it on the street or dyno) will offer a bunch more in options for the A4 calibration. I'm by no means an authority on tuning the A4 trans, but a good tuner can really make a difference here in terms of how the cars drives, shifts, and feels.
Le Mans Master
Joined: Feb 2003
Posts: 6,683
Likes: 144
From: Memphis Tennessee
This seems more complicated than it should. If a 3.42 has a lower top speed than a 2.73 it seems to me that the engine would over rev between shifts not under rev. The 3.42 require less motion to acheive a given speen than the 2.73. To put it simply your 0-60 time will decrease with the 3.42. So I don't see how the engine has to turn more times to rotate the axle if it makes the car faster.
Your car will shift at approximately the same RPM give similar loads as it always did with the 2.73, but with the "lower" gear, it will be going slower. Rev's will climb much quicker with a move to 3.42 allowing a quicker acceleration rate. Many drag-racers find this advantageous, and all find it more "fun" to drive.
Your MPG may be a bit lower, but you will be very surprised how little difference is noticed. All-in-all, a great mod to add to the Corvette experience.
Good Luck
Last edited by ALLEGRO; Feb 26, 2010 at 06:56 PM.
Thread Starter
Tech Contributor
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The car will definitely be drivable without these shift point changes, remember at part throttle and normal street driving, your trans normally shifts way below redline, and it will continue to do that after the gears too. This problem presents itself in WOT runs where it's normally shifting near redline. The gears may push it beyond redline.
Using something like the Hypertech, it will simply alter all the shift points just based on the gear ratio data you enter. Pretty easy way to make the conversion you need done, but that's about the extent of the control you have over it.
Using more complex tuning software like EFI Live or HP Tuners (or having a pro tune it on the street or dyno) will offer a bunch more in options for the A4 calibration. I'm by no means an authority on tuning the A4 trans, but a good tuner can really make a difference here in terms of how the cars drives, shifts, and feels.
Using something like the Hypertech, it will simply alter all the shift points just based on the gear ratio data you enter. Pretty easy way to make the conversion you need done, but that's about the extent of the control you have over it.
Using more complex tuning software like EFI Live or HP Tuners (or having a pro tune it on the street or dyno) will offer a bunch more in options for the A4 calibration. I'm by no means an authority on tuning the A4 trans, but a good tuner can really make a difference here in terms of how the cars drives, shifts, and feels.
Drifting
Joined: Jul 2002
Posts: 1,484
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From: Morgan Hill Ca.
About a year and a half ago I did just what you did and swapped out the 2:73s for the 3:42s and a little more. I have the RPM trans and a 2400 RPM TQ converter.
I bought The HP tuners SW. Like someone said above quite a few inputs to determine shift points.
I do my own setups. Kinda fun. I have several configurations built for my car. You can get flat down more technical than you ever dreamed. Part of the fun is hooking up and straping the puter in the passanger seat and go for a ride, logging data. Bring it home look at the entire run and adjust accordingly.
I have the Dewitts Radiator and a B&M aux tranny cooler sooo she runs cool and in cold weather almost to cool as it will delay the 3rd to 4th shift and lock up on the TQ to a higher rpm.
You will love the 3:42s. Gas milage will drop as you might expect with the gears however I think the foot is probably to blame for most of it. :o
I bought The HP tuners SW. Like someone said above quite a few inputs to determine shift points.
I do my own setups. Kinda fun. I have several configurations built for my car. You can get flat down more technical than you ever dreamed. Part of the fun is hooking up and straping the puter in the passanger seat and go for a ride, logging data. Bring it home look at the entire run and adjust accordingly.
I have the Dewitts Radiator and a B&M aux tranny cooler sooo she runs cool and in cold weather almost to cool as it will delay the 3rd to 4th shift and lock up on the TQ to a higher rpm.
You will love the 3:42s. Gas milage will drop as you might expect with the gears however I think the foot is probably to blame for most of it. :o
