Big gear or not?

2864 Views 20 Replies 8 Participants Last post by JohnDeere9610, Aug 11, 2007

mech2161

Discussion Starter · Aug 6, 2007

I have never tried high side. Do I need the extra wheel speed? Will it help or hurt? Here are the calculations I came up with. I have never snuffed the charger at the end of a pull. Open for ideas.

3rd gear low side
mph rpm
31 4195
28 3789
25 3383
22 2977
33 tire dia

1st gear high side

mph rpm
37 4637
34 4261
31 3885
28 3509
25 3133
33 tire dia

Save

1 - 2 of 21 Posts

bbunting

· #3 · Aug 6, 2007

Kev

You'll know in time to back up and redo things.....but I thought you said your clutch wasn't the greatest, then it wont like the high side.

Save

bbunting

· #7 · Aug 6, 2007

mech2161 said:
Brian SB sent me a new clutch. I missed the opertunity Friday when I had first hook. It could have gone either way after watching some of the gassers. I guess I need to find the balls to just do it. The new clutch works a whole lot better. Bean I have looked at the wheel speed numbers so many times I think it's driving me crazy. I've always done ok where I'm at but this new clutch has me thinking again.

4 lo is much easier to get moving due to the gear reduction, torque multiplication if the transfer case, and input shaft. I have the Iron Giant II with 4200 # plate, and somehow burnt it up in three hooks (it was slipping).

With the powerband on your 7.3, I'd do 4 lo 4th. As I said, you'll know in the first 75 feet if it will work. For DHRA hooks, 4 lo 3rd.

Save

1 - 2 of 21 Posts

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.

Top Contributors this Month