April 6, 200916 yr I was snooping around when I did the gears for my Toyota, and found a crawl ratio calculator. So I punched some numbers using this as a guide to transmission gear ratio's: And what I came up with was; EA81 Dual Range 4spd Crawl Ratio of 20:1 EA82 Dual Range 5spd Crawl Ratio of 22:1 this is with a 3.9 final diff. In comparison, my toyota with the new gears has a crawl ratio of 90:1. And when I stack a second transfercase it will go up to 208:1.
April 6, 200916 yr low gears are overrated!!! no....they're really not I think my Yota, with stock drivetrain and the Auto trans has like a 40:1.
April 6, 200916 yr i have 163.1 right now. 4.44 diffs,6.5 zookie t-case,3.545 ea82 d/r,1.59low soobie. when i grow up i want to buy an atlas t-case for the buggie i WILL build.i will get a 3 or 4:1......cheers, brian
April 6, 200916 yr Saw one on pirate that had a 10.34 low:eek: Was like 2700$ Yipes. i have 163.1 right now. 4.44 diffs,6.5 zookie t-case,3.545 ea82 d/r,1.59low soobie. when i grow up i want to buy an atlas t-case for the buggie i WILL build.i will get a 3 or 4:1......cheers, brian
April 7, 200916 yr So I have a 22:1 My brother has 93:1 I have 27" tyres He has 35" tyres So his first low is 1/3rd of my first low at idle speed... But I still try crawling over every offroad track...
April 7, 200916 yr Author Yeah I wasn't poking fun at Subarus crawl ratio's... just thought it would be nifty to know. 163:1 is impressive for the Sube Brian, I can't wait to see it in action.
April 7, 200916 yr Yeah I wasn't poking fun at Subarus crawl ratio's... just thought it would be nifty to know. 163:1 is impressive for the Sube Brian, I can't wait to see it in action. you and me both.i been getting the tow rig(dodge diesel) up and rollin the last few days.got some work to do on a friends car here pretty quick,and then back at it.mainly i am just waiting to buy some things.so the fund reservoir is slowly being filled up right now.but there is plenty to do between now and then anyway.......cheers,brian
April 7, 200916 yr you and me both.i been getting the tow rig(dodge diesel) up and rollin the last few days.got some work to do on a friends car here pretty quick,and then back at it.mainly i am just waiting to buy some things.so the fund reservoir is slowly being filled up right now.but there is plenty to do between now and then anyway.......cheers,brian yeah, I've been working on my future tow rig ('72 K20) as well... Brat is just sitting in the garage, waiting to be put back together..... luckily most of my spending for the Brat is done... just brake lines and optima left for the most part.....
April 7, 200916 yr So I have a 22:1My brother has 93:1 I have 27" tyres He has 35" tyres So his first low is 1/3rd of my first low at idle speed... But I still try crawling over every offroad track... This is the real issue, a Crawl Ratio does not tell the full tale! Tires are a factor that no one really figures in. I think there should be a "Creep Ratio" ( a ratio that factors crawl and tires together). This would give a more meaningful representation of the ability of a drive train setup. A stock Subaru with stock tires has a reasonable Creep Ratio. When you go over sized with the tires, your crawl ratio does not change. Your Creep Ratio just went in the toilet! Now...just how do you calculate a Creep Ratio to give a meaningful number...
April 8, 200916 yr Author The difference is so small it doesn't really matter. I mean, yes... there is a difference... but it wont make or break anything.
April 8, 200916 yr Now...just how do you calculate a Creep Ratio to give a meaningful number... I just came up with this calculation on the spot, not sure if its good and works but it looks to... My SUBARU 27 inches x 3.14159 Pi =84.82293 inches radius 63360 inches in a mile /84.82293 =746.967 rotations to a mile 1000 engine RPM /22 crawl ratio =45.4545 wheel rotations a minute 45.4545 WRPM x60 =2727.27 WRPH (hour) 2727.27 WRPH /746.967 rotations per mile =3.651 MPH ------------------------------------- My brothers 4RUNNER 35 x Pi =109.95565 63360 /109.95565 =576.23232 1000 /93 =10.75268 10.75268 x60 =645.1608 645.1608 /576.23232 =1.119 MPH 1000rpm in low first Subaru = 3.651 MPH 4Runner = 1.119 MPH
April 8, 200916 yr So this begs the question, What is the Creep Ratio of a stock Subie? Apparently a small change in the numbers makes a big difference in the ability to power the wheels. I notice a BIG difference with 27" tires and the stock tires. Are the stock tires 22" ? I don't have any stock tires left to measure...
April 9, 200916 yr there are gear calculators out there for when going to larger tires, it gives you the new gears you need to have to get back to the stock "feel" power wise. these calcs do not take into consideration additional weight of the tires. http://www.ramblerman.com/blazer/gearcalc.htm And he's a chart where you can see how you move across the bands when changing sizes... http://www.tellico4x4.com/moreinfo/ratio.htm
April 12, 200916 yr Stock, IIRC, is 175/70R13 which equals 23.3" total diameter. I think your wrong.. 175/70R13 should be 22.65" 175 / 25.4 * 0.7 * 2 + 13 = 22.65
April 12, 200916 yr ^correct although, AFAIK EA82 5MT D/R 4WD stock tire size is 185/70r13, which is ~23.2"
April 12, 200916 yr Author I think your wrong.. 175/70R13 should be 22.65" 175 / 25.4 * 0.7 * 2 + 13 = 22.65 You are correct. I used http://www.miata.net/garage/tirecalc.html and I think i left the rim size at 14" or something. My Bad.
April 14, 200916 yr So this begs the question, What is the Creep Ratio of a stock Subie? Apparently a small change in the numbers makes a big difference in the ability to power the wheels. I notice a BIG difference with 27" tires and the stock tires. Are the stock tires 22" ? I don't have any stock tires left to measure... So, doing the math, A stock Subie 22.65" = 3.06 MPH A Subie with 27" = 3.651 MPH 4Runner = 1.119 MPH Apparently a 0.6 change in a ratio makes a big difference! This is the only real ratio that makes sense as it accounts for tires not just gears.
April 16, 200916 yr Dunno about in the US. But every EA82 I 've seen here in Australia has standard tyres size of 175/70R13.
April 18, 200916 yr low gears are overrated!!! IM 100% sure that the wrong gears are not much fun, I just switched the rear diff to 3.9, and the 3.9 5speed w/1.59-1 low range is ready for install sooooon, Roxy still has the P/t RX trans that was awsome for high speed dirt roads with 13's, but not too good for 28.5 swampers. It does jet on the hyway. cant wait to switch. COBCOB beer party wrench day ?????? Edited April 18, 200916 yr by mykingcrab
May 4, 20214 yr Phizinka, the 4WDs were usually 185/70R13, 2WDs were 175/70R13. I have a GL 4WD with 185/70R13 on the driver's door pillar.
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