Desired Track Speed and/or Final Gear Ratio...

R

ross3031

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Feb 22, 2009
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So recently a buddy and I bought a 93 12valve to make into a pulling truck (Big plans, including P Pump). We've never pulled 4wd trucks before, but pulled Semi's for a long time. Just making sure we got the right idea here, somewhere around 25-30 mph track speed, and a final gear ratio of around 16?

Does that sound about right to you boys? Gonna run in 2.6 or 2.8 class...
 
Big time 2.8 trucks are running around 14-14.5 final drive ratio nowadays
 
hp = mph
600 = 24
650 = 25
700 = 26
750 = 27
800 = 28
850 = 29
900 = 30
950 = 31
 
I know of a few 2.6" trucks running 30-37mph wheel speed, really depends on the setup.
 
Not ground speed, no. I would assume that number would be closer to 25-30mph depending on RPM and track condition.
 
Smokem said:
Not ground speed, no. I would assume that number would be closer to 25-30mph depending on RPM and track condition.
Click to expand...

Interested that they run a similar sled speed with tire speeds at 30-37mph than the folks who run 27-33mph. Sounds like they need more traction.
 
The American Ride ran a 28 mph gear at Schieds and qualified for the finals in 2.8 class. Would have love to run like a 30-31 but just doesn't have the power. Must be all about the setup because that truck dyno'd under 700 hp, which I know was probably one of the lowest hp trucks there. And it didn't have duals.
 
lubeowner said:
The American Ride ran a 28 mph gear at Schieds and qualified for the finals in 2.8 class. Would have love to run like a 30-31 but just doesn't have the power. Must be all about the setup because that truck dyno'd under 700 hp, which I know was probably one of the lowest hp trucks there. And it didn't have duals.
Click to expand...

Mine was 31.xx mph ....then it self destructed.:doh:
 
Carried 35 mph the whole track last weekend, but that's because I only had three tires spinning :doh:
 
zstroken said:
Interested that they run a similar sled speed with tire speeds at 30-37mph than the folks who run 27-33mph. Sounds like they need more traction.
Click to expand...

I would assume it is not unusual to see a peak ~ 35mph.
 
Where do you guys get this stuff? I've never done any pulling, but I've been trying to pay more attention. Want to give it a try next year.

Smokem said:
13.22
13.65
13.90
14.05
14.84
15.18
15.44
Click to expand...
So these are final drive ratio's? What do they correspond to? Are they just common #'s that most guys end up with on their different setup's?

lubeowner said:
hp = mph
600 = 24
650 = 25
700 = 26
750 = 27
800 = 28
850 = 29
900 = 30
950 = 31
Click to expand...
And this is just common knowledge? What about torque? How does that factor in? I know hp is just a number calculated from tq.

I was kinda under the impression that it was all about the wheel speed, but it obviously isn't. What is the sweet spot?

A few months ago I was looking into this and I put some of the number's together.
4th gear - 1.39
4 low - 2.72
rear - 3.73
fdr - 14.102

That seemed like a decent starting point, and it looks like I would be right in the middle of the magic chart up there LOL
 
There are more combinations that what is listed, but to digress;

13.22 - direct low 4.88
13.65 - 2nd high 4.10 NV5600
13.90 - direct low 5.13
14.05 - 4th low 3.73 NV5600
14.84 - 2nd high 4.88 NV4500
15.18 - 2nd high 4.56 NV5600
15.44 - 4th low 4.10 NV5600
 
Sandaholic said:
A few months ago I was looking into this and I put some of the number's together.
4th gear - 1.39
4 low - 2.72
rear - 3.73
fdr - 14.102
Click to expand...

Your final would be 14.05, calculate wheel speed in your useable RPM range;

33" tire
3000RPM - 21mph
3500RPM - 25mph
4000RPM - 28mph

35" tire
3000RPM - 22mph
3500RPM - 26mph
4000RPM - 30mph
 
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