[mech2161]

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

 

[HotRodTractor]

If you haven't snuffed out I would at least try it and see how she fairs. Get the momentum built up and hope you got enough power to keep it there.

Definately try it.

 

[bbunting]

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.

 

[bean]

Kev, I have been pullin 4th lo last few pulls and it rocks if the sled is light enough. My rev limiter is only 3400rpms so 3rd lo and 1st hi I could only get around 25mph wheel speed and 4th lo gets me about 31mph. You peak power is around 3000 rpms so I would gear accordingly cause thats where you will spend most of you time down the track once the load is on.

But if the sled is heavy out of the whole then go 1st lo or 3rd hi.

 

[mech2161]

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.

 

[bean]

4th lo is definetly harder on my clutch but mostly due to my big charger. I would say your charger would lite better then mine and be easier to get out of the hole. Two weeks ago I got 24.3 mph track speed out of 4th lo, 1st hi gets me about 21mph track speed.

 

[bbunting]

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.

 

[mech2161]

Humm! I thought 4 low would be too big of a jump. 1st high is between 3rd low and 4th low.
Here's what I come up with for 4th low.
mph rpm
40 4132
37 3822
34 3512
31 3202
28 2892
25 2583
22 2273
33 tire dia

 

[mech2161]

3rd gear low side

mph rpm
31 4195
28 3789
25 3383
22 2977

1st gear high side

mph rpm
34 4261
31 3885
28 3509
25 3133

4th gear low side

mph rpm
40 4132
37 3822
34 3512
31 3202
28 2892

 

[bean]

You are a hair faster then me do to the 3:73's and I have 4:10's but those #'s look real close to what I saw on the street when I was testing my rpm/speed. I say try 4th Lo on loose tracks and 3rd lo on tight tracks.

 

[mech2161]

Well I didn't have the balls to try it tonight since this place has sent me home broken the last three times. Waynesburg PA PPL 8k Open Street 2nd place.
Hey Bean NO BOUNCE the last few times out.

 

[bean]

Whats the secret, I didnt bounce couple weeks ago and hauled ass with the sled, got 1st. Next time out bounced again and got 5th due to it bouncing crap around and knocking one of my TPS wires loose and making the engine go to idle. Also broke loose my over head console and my subs bounced up and crushed the capacitor in the back. Putting bars on the front for this week, gonna air up the bags but leave 1" of travel this time and see if that will help at all.

 

[Sapps]

my subs bounced up and crushed the capacitor in the back. .

:gun:

 

[smorris]

You crushed your flux capacitor??!!
So I guess 88 mph is out of the question now?

 

[mech2161]

Bean
No bump stops, no front bars, rear air bags to 80 psi. When I mounted the bags I installed the upper mount a little higher so it didn't raise the rear too high. The traction bars have no preload in the lowered position. When the bags are inflated it will load the bars to keep the pinion down. Come out hard and break the tires loose as soon as possible. I know to some extent I'm giving up some distance with this set up. But no bounce. I can try to get some distance back now without breaking everything.

 

[bean]

If you can get rid of bounce there is your distance, hard to pull when th etires are off the ground.

 

[mech2161]

LOL I guess you may be right. A second and a third within a week looks good.

 

[House]

gone try no suspension stops friday night just the added leafs

 

[mech2161]

This is a through back to my beginning. Truck never bounced before I added stops. Tried to add everything else to make it stop. The only thing I have are bags and bars.

 

[bean]

Pulled 4th lo again last night on a tight track, clutch didnt like it for first 100+'
but once the clucth locked in it was on. Pulled 344' and second place was 296 I think. Next track is tonight on a loose track so it wont be quite as hard on my clutch.