Anyone recommend 4:30's for a 02 gt/AUTO?

big T

New Member
Feb 25, 2004
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Hawaii, oahu
Is it too much gear?, or is 4:10s right? I would like to still get to at least 130-135 mph. I use the car for daily driver, also looking at 13.5-.7 in the 1/4... Is superchips a good programer to use with the auto's,I hear that they are the expert's at the automatic trans cars from ford. How much quicker in the 1/4 between the two a .1 or so.
 
big T said:
Is it too much gear?, or is 4:10s right? I would like to still get to at least 130-135 mph. I use the car for daily driver, also looking at 13.5-.7 in the 1/4... Is superchips a good programer to use with the auto's,I hear that they are the expert's at the automatic trans cars from ford.
4.30's will feel faster, but if you are daily driving on the highway and don't like being at high rpm for long periods of time, go with the 4.10's, they are high enough on the highway as it is.
Definately get a chip so you can sharpen up those shifts and get the
speedo corrected.
-wade
 
Im having 4.30's installed soon along with some other goodies.:D
I know its not too much gear. Hell, I was even tempted to go with 4.56's.:eek: You can still go 135-140 mph. As a matter of fact, with a 26in(stock height) tall tire on the rear and a 6,200 rpm rev-limiter, you can still hit 150. No kidding either. Although I kind of wonder why you want to go that fast, still, you can do it(please dont for the sake of the public). Superchips is a good company. Unless if you get the racer tuner package(which is really expensive), I'de recommend a dyno tune or chip over that. I'll probably go with a chip from Superchip.
 
KJ Hoppus. I did some research. You'de tap out 3rd gear doing 106.Xmph@6,200rpms. Thus, you might run out of gear in the 1/4 mile. If you have internal work done and your rev-limiter and shift points are up to around 6500 rpms, then 4.56's would probably work without fear of running out of gear in the 1/4 mile and having to shift at the end.
 
You guys are crazy doing top speed runs. The other day I had a clear road ahead of me and my radar detector on so I decided to give my car a little stretch, and at about 100 mph things move so fast that I wouldn't wanna risk attempting 140 or 150!

I would get 4.10s right now if it wasn't for the gas mileage. 4.30s would be even WORSE gas mileage.
 
big T said:
Thx again, want is the diff in the 1/4 betwn the 2 a .1 or .2 or something. Just curious.

Depends if you have tires / suspension to get traction in 1st gear really. I have a hard enought time with 4.10s and 18s. The difference wouldnt be huge, 0.1 at most I'd guess.
 
jas142 said:
You guys are crazy doing top speed runs. The other day I had a clear road ahead of me and my radar detector on so I decided to give my car a little stretch, and at about 100 mph things move so fast that I wouldn't wanna risk attempting 140 or 150!

I would get 4.10s right now if it wasn't for the gas mileage. 4.30s would be even WORSE gas mileage.
*cough* pussie *cough* No, seriously though. Way to think. I wish more drivers would get that mentality in their heads. Fast does not equal cool...well except in quarter miles. Ah, f*** it, you know what I'm talking aboot. [/canadian]
 
i would not recommend the 4.30's.

#1) you will need a good suspension/tires in order to make proper use of those gears

#2) you will max out 3rd at 106. if you plan to run faster than 106 in the 1/4, you are screwed. going into o/d at wot is not good.

#3) your gas mileage will suffer. since it's a DD, i would think it would be of some concern to you. especially with gas being $2 a gallon.
 
DBMSTNG said:
i would not recommend the 4.30's.

#1) you will need a good suspension/tires in order to make proper use of those gears

#2) you will max out 3rd at 106. if you plan to run faster than 106 in the 1/4, you are screwed. going into o/d at wot is not good.

#3) your gas mileage will suffer. since it's a DD, i would think it would be of some concern to you. especially with gas being $2 a gallon.

With 4.56's you'll max out 3rd gear at 106mph. If you have a 6200 rpm rev-limiter, you can tap out 3rd gear with 4.30's at about 110 mph. Thats plenty for the auto in the 1/4 mile.

I agree about the suspension and tires though. As for gas mileage suffering, there is hardly any difference between 4.10s and 4.30s in terms of cruising rpms and gas mileage differences. You probably wouldnt even be aware of the difference.
 
Dark Knight GT said:
With 4.56's you'll max out 3rd gear at 106mph. If you have a 6200 rpm rev-limiter, you can tap out 3rd gear with 4.30's at about 110 mph. Thats plenty for the auto in the 1/4 mile.

I agree about the suspension and tires though. As for gas mileage suffering, there is hardly any difference between 4.10s and 4.30s in terms of cruising rpms and gas mileage differences. You probably wouldnt even be aware of the difference.


my GT does 140mph in 3rd. (140*3.27)/4.30 = 106. granted that's at 6000rpm. fuel cutoff is at 6050. raising the rev limit on stock heads isn't a good idea. the car is his daily driver, so it would be best for him to be on the safe side.

as far as the gas mileage, i ment the difference between the 4.30's and stock. not the 4.10's. i should have made myself more clear. again, you have to take into account that this is his daily driver. and that is why i mentioned it may be of some concern to him.
 
Guys rev their motors up to 6,500 rpms with the stock heads, cams, and block without any problems. The cams in the 99+ GT's still pull pretty hard up until 6200 rpms thus I recommend putting the rev-limiter there. It can be done without problems.

EDIT: Accordingly to a gear calculator I have, a 4r70w automatic will tap out 3rd gear doing 6,[email protected] mph. Although thats not much difference than 106mph, its still a little bit higher. It will also tap out doing 6,[email protected]. Thus, I believe 4.30 gears are the perfect gear for a n/a auto GT. If you have cam/ cylinder head work done and your power band is broader, Ide say 4.56's are the gear for you.