GMC - DANA 44 - which gears to buy?- I wanna burnout!!

[boucher racing]

Originally Posted by Brad54

Are those 3.54 gears OE or aftermarket?

-Brad

The gears are from the factory, 3.54

Originally Posted by kieth

Do not know why you would change out to the 4.10, the first gear in your 700r4 is really low, it should burn rubber right now.......try it before going through the gear swap, send me the diameter of your rear tires, the engine that you run, and we will calculate speeds and usable torque to the ground so you can see how your burb will perform before you change the gears......Kieth

Kieth, first of all thanks for the spreadsheet. It is really useful. To answer your concern. I used your spreadsheet and came up with this.

I am comparing the new set up with my old setup (T5). With the 3.54 / T5 setup, I was turning 2300 rpm at 70 mph. With the 700R4 and 4.11 gears, I will turn 2300 rpm at 69 mph, so it is very close. I did like the highway setup with the T5, nice power on tap at 70 mph. It did not lug, it seemed to be at a sweet spot.

Also, look at the power ratio off the line (1st gear X rear ratio)

T5 - 3.76 x 3.54 = 13.3
700R- 3.06 x 3.54 = 10.8
700R with 4.11's- 3.06 x 4.11 = 12.6

The T5 in first launched really hard. Now looking at the 10.8 number, it sort of explains why it feels weak. The 4.11 gears get the power ratio close to that of the T5.

So... I am pricing a set of "thick" cut 4.11 and install.

We shall see!

Boucher'