MPH - how much extra?

Mopower · Mar 16, 2014

If you're a little shy on power to run low rpm & high gear at a certain speed limit, what is the minimum extra wheel speed you prefer to have on tap at full throttle to stay competitive? For example: 4mph top wheel speed in a 3mph class. (I pull a UB capable of about 5.5mph under a stiff load in 4&5mph classes.) Feel free to expand on your preferance, why, and variables involved. It'd be nice to hear what everyone thinks.

Mike Bock · Mar 17, 2014

you got it about right maybe 1 mph over limit , if you have enough power , traction will win over speed though ,dont be discouraged if you cant run with them you can still out pull them

PretendFarmer · Mar 18, 2014

(quoted from post at 03:35:44 03/18/14) you got it about right maybe 1 mph over limit , if you have enough power , traction will win over speed though ,dont be discouraged if you cant run with them you can still out pull them

I agree however you'll rely on skill and a good eye for the track to beat a tractor with a half competent driver if he has twice the horses.
I've done it. It's fun when I do, but its not easy.

Superih · Mar 18, 2014

At stock rpm;

NATPA Div3 is 3.5 mph, I run a 6 mph gear.

Summer pulls at 4.5 mph I run a 7.4 mph gear up to 5500 then drop to 6.6 mph gear.

778899m · Mar 18, 2014

Slippage is a huge factor,one MPH is fairly good,experience and skill with luck is a good combination too.Being "one" with the tractor is important,knowing how to read it's reaction to different parts of the track. Div. II you need 100 hp in the 4500# class !!!!! On some good tracks I have had to slow up when I hit solid traction after getting thru some rough spots,just depends,it is not always get on,go and hang on,even in the lower mph classes,it is a driver's skill that wins mostly.

mightymolinekid · Mar 18, 2014

We were at a pull this past summer, there were 3 JD Gs there that ran 4 and 6 mph from 4500 up through 6500. In the 6 mph class, they topped out at 5.5, and never slowed down until the end when they spun out. In the 4 mph class I don't recall them bumping 4 but 3.7-3.8 all the way down the track, it didn't appear that they had rpm left....they totally dominated that day, the best I could get was a 3rd. Their set-up was perfect all day, 18.4/38 Firestone SATs on the back, they just marched down the track. My question is, many years of experience and a well built and tuned machine, do you need a bunch of rpm left? I don't know, but they didn't. I will try again next year, and hopefully I'll at least get a 2nd...I know one in particular I'll never beat unless he breaks something at 50 ft. Lol

VicS · Mar 18, 2014

It's like a lot of things in pulling. Doesn't always help to be able to have a lot of reserve. Our WC will run 6 mph with 18.4X34's. Last summer I pulled it with the 435 tires, while it was down. The 435 will just run 4 mph with no load. On the average the 435 will beat the WC. Last summer the 435 won the 4000 4 mph class at Evansville In. pull, 3 tracks pulling. There were RD 460's and 320 Olivers. At the end they couldn't help pushing the throttle open and spinning wildly. So sometimes extra power doesn't help. And yes I have came in last. 66ft total.
The only reason I can come up with is the JD final drives are straight back, and the WC finals are turned straight down. So the center of gravity of the JD is lower. If the rules would let the AC's turn their final drives straight up I think they would dominate the lighter weight classes.

Vic

MPH - how much extra?

Mopower

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Mike Bock

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PretendFarmer

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Superih

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778899m

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mightymolinekid

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VicS

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