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View Full Version : What is your crawl SPEED!!!!!


mahana79
02-16-2006, 12:36 PM
This give a new outlook on things instead of finding the standard crawl ratio.

http://www.4x4help.com/resources/calculators/final-ratio.htm

I did mine at 1000 RPM instead of 750. just a little more realistic to trail speed.

Drivetrain:
Tracker Auto 1st: 2.40 3rd: 1.00 Reverse: 2.00
Toy range box: 2.28
Dana 300: 2.62
R&P: 4.10
37" tires


results without factoring in Torque Converter multiplication

Calculation Results
Forward Crawl Ratio: 58.78022 to 1
Forward Movement @ 1000 RPM: 2.74655242432547 Feet per second
Reverse Crawl Ratio: 48.98351 to 1
Reverse Movement @ 1000 RPM: 3.29586342253555 Feet per second
Highway Speed @ 2000 RPM: 53.6949976449363 MPH

Results factoring in a 2.5 torque multiplication from the converter (note: TCI says most torque converters give a torque multiplication of 2.5 at intial start so I multiplied first gear and reverse by 2.5 and use those numbers, I didnt change 3rd gear because at cruising speed the torque converter balances out at a 1:1)

Calculation Results
Forward Crawl Ratio: 146.9505 to 1
Forward Movement @ 1000 RPM: 1.09862134047941 Feet per second
Reverse Crawl Ratio: 122.4588 to 1
Reverse Movement @ 1000 RPM: 1.31834506100726 Feet per second
Highway Speed @ 2000 RPM: 53.6949976449363 MPH

Billjohn
02-16-2006, 03:18 PM
Well, it looks impressive but I'm not convinced that my trail rig will do 99mph...
http://www.billjohn.com/calc.jpg
The calculation doesn't take into account the fact that my gearset has a high range of about 1.7:1
This would bring my speed down to about 58mph... which is about right for 4500 RPMs...

DesertZuki
02-16-2006, 09:03 PM
The calculator doesn't like Firefox. IE was okay.

I get the same thing as Bill, at 5400 RPM I have a top speed of 165.2 MPH.

Regardless, I know I have to lower my crawl speed. I believe my next drive train change will be putting in the Trac/Kick 2WD auto behind the 16v (I already have it). Otherwise I really like that OTT dual t-case set up. I have to do something though, 56:1 crawl ratio sucks. (It was actually okay for most stuff before I changed the clutch, but now I have new "grabby" clutch - looks like I never drove before - embarrasing and hard on the rig).

mahana79
02-16-2006, 10:14 PM
The calculation doesn't take into account the fact that my gearset has a high range of about 1.7:1
This would bring my speed down to about 58mph... which is about right for 4500 RPMs...


Yeah that is the only thing it doesnt do. it assumes that your high range is 1:1

Vagabond
02-17-2006, 01:11 AM
Try this one:
http://phill.kenoyer.com/gears/

mahana79
02-17-2006, 10:26 AM
Try this one:
http://phill.kenoyer.com/gears/


Nice

it needs a spot for a range box jamminzz

TatorZuk
02-19-2006, 09:45 AM
Both very cool...thanks guys.bigok

maxduty
02-19-2006, 10:06 AM
Gear Setup Summary
Your transmission's lowest gear ratio is 3.652 : 1
Your transmission's highest gear ratio is .795 : 1
Your transmission's reverse gear ratio is 3.466 : 1
Your transfer case's gear reduction ratio is 6.4 : 1
Your crawl box's gear reduction ratio is 2.0 : 1
Your final drive ratio is 5.13 : 1
Your tire diameter is 39.5 in




Calculation Results
Forward Crawl Ratio: 239.8049 to 1
Forward Movement @ 1250 RPM: .898393 Feet per second
Reverse Crawl Ratio: 227.5914 to 1
Reverse Movement @ 1250 RPM: .946604 Feet per second
Highway Speed @ 2000 RPM: 57.62733 MPH

mahana79
02-19-2006, 10:31 PM
Gear Setup Summary
Your transmission's lowest gear ratio is 3.652 : 1
Your transmission's highest gear ratio is .795 : 1
Your transmission's reverse gear ratio is 3.466 : 1
Your transfer case's gear reduction ratio is 6.4 : 1
Your crawl box's gear reduction ratio is 2.0 : 1
Your final drive ratio is 5.13 : 1
Your tire diameter is 39.5 in




Calculation Results
Forward Crawl Ratio: 239.8049 to 1
Forward Movement @ 1250 RPM: .898393 Feet per second
Reverse Crawl Ratio: 227.5914 to 1
Reverse Movement @ 1250 RPM: .946604 Feet per second
Highway Speed @ 2000 RPM: 57.62733 MPH

Now that is crawlin'!!!!!!!:shocked!: bigok jamminzz

Ruttdigger
02-20-2006, 03:34 PM
133.4587 crawl ratio
top speet 104... Only because you would have to drive off a cliff and that would be the terminal velocity.