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Discussion Starter · #1 · (Edited)
I have a 95 GT and just did the following upgrades.

I installed a FRPP Wide Ratio Gear set making is basically a 4R70W.

- Precision Industries Stallion 2400 Stall Convertor
- FRPP Gear Set
- PA Hardened Input Shaft
- Level 10 Automatics Hi-Flow Pump
- Karl Baumann Valve Body Shift Kit
- B&M Deeper Pan (holds an extra 3 qts.)
- Long Trans Cooler

Here is my situation....I am bouncing back and forth on what rear gears I want. Most people jump to say 4.10's cause it is an Automatic.

One of my friends with a AOD and the FRPP Wide Ratio Gear Set said this in an Email "3.73's is as high was i would with my AOD. I'm running out of gear as it is at the end of the 1/4 mile crossing at redline in 3rd at 100-101MPH. If i had 4.10's i would need to shift to OD."

3.73's or 4.10's? This will be a daily driver....I have a 92 LX with a 5 speed and 3.73's and at about 70mph I am at about 2400 RPM.

According to Karl Baumann with the stock rer 3.27's the car has now and combined with the FRPP Wide Ratio Gear Set - first is about a 3.87 Gear.

What so I do guys? I don't wanna run outta gear in the 1/4. Am I going to run out with 4.10's?

Also, how hard is it to swap the speedo gear on an Automatic? Do I use a 23 Tooth for 4.10's? What do I use?

Thanks guys!
-R
 

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I have the lower 1 & 2 gears in my 94gt with 3.73 gears and like it for daily driving. I think 4.10 would be fun, but it wouldn't be any faster as first and second would do nothing but spin. Traction is hard enough with the 3.73s. But I have a 347 and lots of other goodies so trying to compare is a waste.

Who cares what I or anyone else think, Do The Math yourself and decide on the numbers you want and how it matches your cam, and other goodies.

RPM = (MPH / (Tire Radius / 168) ) * (Axle ratio * gear ratio).

Build a spreadsheet for each of your gears and each rear gear set and figure out what works best for you in each and every gear.
 

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Discussion Starter · #5 ·
Don 95Vert said:
I ran 123 MPH with my 4R70W and 373's and really didn't over-rev the engine - my rev limiter was 6200... You'll be fine.

You do need a chip to tell the EEC that the auto gear ratio has changed and to keep from hitting the limiter on shifts...
The car was tuned with SCT Software and the shift points were changed to 5500 instead of stock.

Do I still need to re-tune after I install gears? :confused:
 

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Since my 2000 has that trans, I'll chime in. I am looking at the gears, and decided on the 4.10's. It is right for that engine. But about the trap speed. On the calculator, or formula, I can hit 108 at 5800 rpm with 4.10's in direct, and 119 or so with 3.73's.

The formula I have is (all the same result anyway) RPM= (gear x rear end x mph x 336) / tire diameter.
 

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Discussion Starter · #7 ·
JNMA71 said:
I can hit 108 at 5800 rpm with 4.10's in direct
:eek:

I hit the 1/4 at 106mph N/A on my 92 with 3.73's.

I am thinking about doing an S-trim with this car.....maybe I should do 3.73's

Seems like I am gonna run out of gear with 4.10's an S-trim and the AODE.

-R
 

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Discussion Starter · #10 ·
Don 95Vert said:
Yep - A reburn just for the new gearset.
What a nightmare....

and the advantage to this is that I will not need to install the 23 tooth gear or that it will read correct?

There are not many people here in NJ that tune with SCT. They are few and far between...

-R
 

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Discussion Starter · #11 ·
JNMA71 said:
You run to 5800 with a stock 5.0?
in or around 5500....

The cam I have is designed to stop making power around 5500 so that is where I shift.
 

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It's an old school 5.0L at about 400 HP. 4R70w trans and torque converter that was behind a V6. Right now it has 273's I guess because of the V6. I have a set of 373's I'm dropping in.
It's built for a playtoy. No plans on a daily driver. Might take to strip just to see what it will do.
 

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