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convertible gears

regalniz

Well-known member
Joined
Apr 8, 2002
Messages
194
Location
vegas baby vegas
Corvette
94 Polo Green Convertible w/auto
i heard that the performance axle ratio is different for coupes and convertibles. i have an auto and always thought i had a 3.07 rear. now i heard i might have 2.59's because its a convertible. i do exactly 2000 rpm at 70. any thoughts.
 
Roadsters got 2.73 gears as the "performance" axle. Look on your RPO code sheet for RPO G92 "Performance Axle Ratio" and GU2 2.73 gearset.

The 2.59 ratio was standard on A4-equipped roadsters. The 3.07 came with the 6-speed.
 
im a little confused. i do have the g92 code on my console. thats why i thought i had 3.07's. so i have 2.73's, because its a automatic convertible. so the code g92 is different for coupes and convertibles? so confusing.
 
G-92 performance Axel

You have 3:07 gears the G-92 is the same for all C-4's as far as I know.
 
G92 is the code for the (so-called!) performance axle and is the same code for both coupes and roadsters. The other code (GU2) specifies the ring and pinion combination installed which defines the ratio itself. Go to the Model Center to find the RPO codes for the various ratios that were available.
http://www.corvetteactioncenter.com/tech/rpo/8496rpo.html

My 92 A4 roadster has G92 and GU2 installed. The G92 option was all of $50!
 
Axle Ratio

My build sheet list the code as GM3 and 3.45. So does that mean i have 3.45s. it is a 6 speed
 
regalniz,
If you have the G92 then it is a 3.07. At 72mph you would be running exactly 2000rpm. 2000=(((3.07*72)/26.0)*336)*0.7

first,
yes 3.45 with 6sp in 91. Only option was GM4 - 3.54. I haven't heard of too many ordered with that.

c4cruiser,
the 3.07 was the default in the early 4+3 cars. once the 6sp came out they started with 3.33, then moved to 3.45. there is no 6sp with a 3.07.

graham
 
hey thanks for clearing that up. deep down inside i was wishing i had 2.59's so that when i get my 3.54's, i would notice it big time. got to put in a little more overtime.
 
regalniz said:
hey thanks for clearing that up. deep down inside i was wishing i had 2.59's so that when i get my 3.54's, i would notice it big time. got to put in a little more overtime.


hehehe :D

Yeah you bet. I swapped from 2.59 to 3.54. What a wakeup call for the car. Definetely the thing it was missing. You should still feel a difference even going up .5. Most certainly going up 1.0 made a huge difference. In 2nd gear the A4 should be a blast for low speed autox. I'll find out in a few weeks :Steer

Graham
 
I know I have the 2:59's on my 89 auto convertible. I turn 1,700 RPM at 70.

Radar :)
 
regalniz said:
hey thanks for clearing that up. deep down inside i was wishing i had 2.59's so that when i get my 3.54's, i would notice it big time. got to put in a little more overtime.

in 94 GM1 is the 2.59 , G92 is a 3.07

Get 3.73 gears, the cost difference should be minimal. I don't think you're going to be as happy going from a 3.07 to a 3.54.
 
I have 3.45 gears on my convertible. I have a 6spd, and that is why. I think the 6spds came with these gears.

Besides looking at the option codes, you can check physically. One way is at 60, in Drive (1:1 ratio) what is your rpm? that will indicate your rear end ration.

The other is to spin the drive shaft and see how many times the wheel turns. That will give you the differential ratio as well.
 
Topless said:
I have 3.45 gears on my convertible. I have a 6spd, and that is why. I think the 6spds came with these gears.

Besides looking at the option codes, you can check physically. One way is at 60, in Drive (1:1 ratio) what is your rpm? that will indicate your rear end ration.

The other is to spin the drive shaft and see how many times the wheel turns. That will give you the differential ratio as well.

YEs 6spds got the 3.45 mostly.. some 6 spds did however get 3.33 gears
 

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