PDA

View Full Version : What does...


subzali
11-26-2007, 04:58 PM
90:1 - 96:1 gear reduction feel like?

I've seen upwards of 130:1 and just wondering how high do you need to go? Stock FJ40 is about 25:1-28:1 depending on year, so what's the difference between 3x as slow and 4x+ as slow? What kind of obstacles (take Moab for example, or others) would need something more than a 90:1 ratio?

Uncle Ben
11-26-2007, 05:47 PM
90:1 - 96:1 gear reduction feel like?

I've seen upwards of 130:1 and just wondering how high do you need to go? Stock FJ40 is about 25:1-28:1 depending on year, so what's the difference between 3x as slow and 4x+ as slow? What kind of obstacles (take Moab for example, or others) would need something more than a 90:1 ratio?

That is the million dollar question my friend! Silly low often helps more for control and descending big rocks. Climbing takes a gear that crawls slow enough for control but also carries enough margin of acceleration for a bump if needed. Just the addition of an SM 420 to your mix would yield 66.65! Which is pretty low. Add 4:56 gears and now your playing with 73.94:1! 4:88's = 79.13!

The fun fact is 1st gear in a 420 in high range with 4:11's is 28.98:1 which is lower than what you have now in low range!

Example of stupid low obstacles in Moab would be Can Opener, Rocker Knocker, No Name and Yellow Hill on Pritchett, Rock Chucker and Mirror Gulch on Metal Masher, Pot Holes, (http://youtube.com/watch?v=HNxr1k-cwmw)Several challenges on Tie Rod Flats, Golden Crack (and obstacles around it) and Body Snatcher on Golden Spike, etc.... Other obstacles are just as tough but often can't be crawled due to physics (lifting a vehicle weight straight up without full traction).

subzali
11-26-2007, 05:52 PM
Well I'm thinking H41 (4.925) or H55F (4.84), Orion 4:1, and 4:56 or 4:88 diffs, which would yield around 90:1.

Uncle Ben
11-26-2007, 06:01 PM
Well I'm thinking H41 (4.925) or H55F (4.84), Orion 4:1, and 4:56 or 4:88 diffs, which would yield around 90:1.

Awesome combo! remember 4.88's are a PITA to get C-clips back on in a semi float! .....and the higher the number the weaker the pinion strength!

nuclearlemon
11-26-2007, 06:14 PM
Well I'm thinking H41 (4.925) or H55F (4.84), Orion 4:1, and 4:56 or 4:88 diffs, which would yield around 90:1.

it'll make driving to the trailhead suck. stick with 4.10s and the orion.

Rzeppa
11-26-2007, 06:38 PM
I REALLY liked the 5:1 of the H55F, about the same as the H41 I put into my 76 but haven't driven yet. I'd say the Orion is probably the best way to go, but they sure are expensive. Thing I don't like about SM420/465 is you're basically now a 3 speed tranny, never use granny gear on the road. Plus I hate the way they shift, Toyota trannies are so much smoother.

I've seen a number of instances where somebody with too-low gears couldn't make it because they didn't have enough mo and had to back up, put it into a higher gear and try again. The "Ugly" of the Good, the Bad and the Ugly on Steelbender comes to mind. Usually it's where the traction is loose, crumbly, slick, etc.

treerootCO
11-26-2007, 07:12 PM
If you smell your clutch every time you wheel, you need lower gears. A bigger motor would also be an acceptable answer. The one answer I won't accept is driver experience. It is a pain in the a@@ keeping the engine lugging along without slipping the clutch or beating the piss out of yourself and rig.

treerootCO
11-26-2007, 07:14 PM
http://www.root45.com/SM465Orion/Gears.htm

save and open in Excel and you can play with the gearing combos. I was too lazy to write the html.

treerootCO
11-26-2007, 07:16 PM
Come over and you can borrow the 40 as long as you like. Take it wheeling, beat the piss out of it....and yes I am serious

Romer
11-26-2007, 07:55 PM
If you smell your clutch every time you wheel, you need lower gears. A bigger motor would also be an acceptable answer. The one answer I won't accept is driver experience. It is a pain in the a@@ keeping the engine lugging along without slipping the clutch or beating the piss out of yourself and rig.


Course now that you have an 80 you won't have to worry about the burning clutch smell

RockRunner
11-26-2007, 09:22 PM
Lower gearing can be a great thing and a handicap. I am running dual cases in my 4runner with 5.29's. When I run the 2.8 Tcase and wheel different areas it takes a little more finesse with the throttle and or clutch. When I use the 4.7 case alone those areas are far more easy to handle and I can control the speed of ascent or descant with the throttle. Also with the 4.7 engaged I can apply the brake without having to use the clutch and worrying about stalling the engine, within reason.

When using both cases I drop down to 223/1 and crawl at 1/3 mph with total control. I can just about apply the brake fully and not stall the motor. This makes finesse crawling feasible and some of the harder trails a lot more fun. Like some of the others mentioned finding the right gear can be a trying experience.

I know this isn't exactly what you are looking at but lower gearing makes wheeling a lot more fun. Some obstacles that were impossible before become possible with lower gearing. Driving to the trail is a little harder with lower gears and the gas mileage does suffer if it is a DD but what you get in return is worth it.

I hope this helps somewhat, or maybe it tickled your mind regarding a dual transfer case ;-)

nuclearlemon
11-26-2007, 10:36 PM
I hope this helps somewhat, or maybe it tickled your mind regarding a dual transfer case ;-)

this from someone who towed to the trail :D

problem with an fj40 is lack of room for dual tcases. you end up with a 12" shaft...and that's in male measurements:hill:

bigbluefj
11-27-2007, 12:50 AM
sm420 and 4.88's are nice on the the trial and add the compression of a 350 and it's really nice going down hill ...

RockRunner
11-27-2007, 11:13 AM
this from someone who towed to the trail :D

problem with an fj40 is lack of room for dual tcases. you end up with a 12" shaft...and that's in male measurements:hill:

I would have driven there but the comfort of my DD is to great. Also I need to know how it handles, it did pretty good. This way I have three options for Moab, most likely I will still trailer it out there, just incase :rip: it rolls.

Not to familiar with the 40's would love to have one but $$$$ i do understand the 12"s that is a tough one ;)

wesintl
11-27-2007, 11:48 AM
Well I'm thinking H41 (4.925) or H55F (4.84), Orion 4:1, and 4:56 or 4:88 diffs, which would yield around 90:1.

I kinda like that combo with 4.11's. As you know blow a pinion and you have to build another diff with 4.88's or have some flown in. It's easy to find a 4.11 chunk and plop it in and move on. for example look at nutleys rig. I still think he's runnin 4.11's

subzali
11-27-2007, 12:13 PM
What are the guys in 80s running in their diffs with 35s (nakman, Romer, Uncle Ben, etc.)? 4:56 or 4:88? Looking at the H55F, in 5th gear at highway speed on 35s and 4:88s I would be spinning 350 rpms less than I do now, but then if I drop it into 4th for hills then I would spin about 150 rpms higher than I do now to help with engine power (maybe).

Uncle Ben
11-27-2007, 12:24 PM
What are the guys in 80s running in their diffs with 35s (nakman, Romer, Uncle Ben, etc.)? 4:56 or 4:88? Looking at the H55F, in 5th gear at highway speed on 35s and 4:88s I would be spinning 350 rpms less than I do now, but then if I drop it into 4th for hills then I would spin about 150 rpms higher than I do now to help with engine power (maybe).


4.56's will take it to close to stock gearing with 35's but of course rolling resistance of the 35's vrs the 31's will factor in and kill some responsiveness. I (and most) am running 4.88's in the :kevin: with 35's. Again remember, 80's don't have c-clips! 80 guys who run 37's or bigger used to do the 5.29's but pinion strength is an issue and the new trend is back to 4.88's or shorter and lower t-case gearing.

subzali
11-27-2007, 12:34 PM
Right, I'm thinking way future - full floater rear.

AxleIke
11-27-2007, 03:41 PM
My truck is 90.6. If you'd like, you can drive it at the next meeting (i should be there).

While it is awesome for many CO trails, there are a few types of obstacles where lower would be a whole lot better, and many trails where it is way too low.

Lower would be for rock gardens. You don't need a bunch of speed and power, but you just don't want to have to work the clutch. On 4 runners at abou 215-228:1, it is perfect. You can idle over everything up to about 2 ft boulders, any bigger and you need to give it a little gas.

The other great option is having stock low range for the cruising parts of the trails.

Obviously, this won't work in a 40. If it were me, with a 40, I'd go with a 4speed tcase from one of the vendors. I just can't get enough of the gearing options.

Rzeppa
11-27-2007, 07:36 PM
While it is awesome for many CO trails, there are a few types of obstacles where lower would be a whole lot better, and many trails where it is way too low.

Lower would be for rock gardens. You don't need a bunch of speed and power, but you just don't want to have to work the clutch. On 4 runners at abou 215-228:1, it is perfect. You can idle over everything up to about 2 ft boulders, any bigger and you need to give it a little gas.

Obviously, this won't work in a 40. If it were me, with a 40, I'd go with a 4speed tcase from one of the vendors. I just can't get enough of the gearing options.You guys with 22REs and such have to remember that with an F or 2F (or better yet, a 3B or 1HZ) you get 90% of full torque at 1000 RPM, and can lug that big ol' straight six down to less than 500 RPM and still get up the trail.

Al Ostoff (who has a V8J40) rode with me up the Rock Garden of Spring Creek one year and had forgotten how slow these motors can go. It sounds like it's going to stall, then a bit of skinny pedal and it just grunts right through. Neil Quigley had to drive his 40 at Moab last year because of issues with his runner, and he told me how he had almost forgotten how much different driving a 40 is from a runner, as far as technique. They are like tanks, and the extra low grunt of the stock motor reduces the need for lower gears.

No question, lower gears have their place, but with the stock motor you can do a lot you would have more trouble with a motor that didn't have as much low end. Everything's a trade-off though and there are pros and con's to everything from stock to modified and one model type to the next. And as my friend Wayne Smith says, which I tend to agree with, "the farther you get from stock, the more you sacrifice that Toyota Reliability".

ScaldedDog
11-27-2007, 09:25 PM
You guys with 22REs and such have to remember that with an F or 2F (or better yet, a 3B or 1HZ) you get 90% of full torque at 1000 RPM, and can lug that big ol' straight six down to less than 500 RPM and still get up the trail.

At 200:1 and 3.0 in my 4500lb-5000lb 4Runner, I could idle up that steep incline at the end of the loop on Fins. 300rpm and it took the better part of minute to climb the thing, but it did it consistently. That was with 35" radials, though, I don't think I could do it with 37" bias ply's. Lot's of rolling resistance at 5psi, in addition to the increased diameter.

Idling through the Crack with no feet on the pedals is kind of fun, too. :D

Mark

Rzeppa
11-27-2007, 09:38 PM
300rpm and...Just curious...what engine will run at 300RPM?

ScaldedDog
11-27-2007, 10:52 PM
Just curious...what engine will run at 300RPM?

3.0 V6. Downey headers and a Jacobs ignition are the only real modifications.

Mark

AxleIke
11-27-2007, 10:52 PM
You guys with 22REs and such have to remember that with an F or 2F (or better yet, a 3B or 1HZ) you get 90% of full torque at 1000 RPM, and can lug that big ol' straight six down to less than 500 RPM and still get up the trail.

Al Ostoff (who has a V8J40) rode with me up the Rock Garden of Spring Creek one year and had forgotten how slow these motors can go. It sounds like it's going to stall, then a bit of skinny pedal and it just grunts right through. Neil Quigley had to drive his 40 at Moab last year because of issues with his runner, and he told me how he had almost forgotten how much different driving a 40 is from a runner, as far as technique. They are like tanks, and the extra low grunt of the stock motor reduces the need for lower gears.

No question, lower gears have their place, but with the stock motor you can do a lot you would have more trouble with a motor that didn't have as much low end. Everything's a trade-off though and there are pros and con's to everything from stock to modified and one model type to the next. And as my friend Wayne Smith says, which I tend to agree with, "the farther you get from stock, the more you sacrifice that Toyota Reliability".

Ahhh, that is a good point. Especially about Toyota reliability.

I didn't realize the LC motors were that good.

My 22RE hits the power band at 3k. As far as torque goes, I needed 1500 in stock low range just to make it go. With the lower tcase, it does pretty well at 1000.

Red_Chili
11-28-2007, 09:04 AM
And as my friend Wayne Smith says, which I tend to agree with, "the farther you get from stock, the more you sacrifice that Toyota Reliability".
Ahhh, that is a good point. Especially about Toyota reliability.

I didn't realize the LC motors were that good.

My 22RE hits the power band at 3k. As far as torque goes, I needed 1500 in stock low range just to make it go. With the lower tcase, it does pretty well at 1000.
Somewhat true about Toyota reliability for stock, but I have found that with drivetrain that ain't necessarily so. My FF rear for instance. Or combining Toyota parts that were never connected to each other from the factory, but work fantastically. Not a hard and fast rule, there are many 'opportunities' even in Toyotas.

A man made it, and a man or woman can fix it better. It's all synthetic.

I am running about 230:1+ with the R151, and use it. And I drive to trails, and daily driver (except for fear of theft or vandalism). It ain't too low. I use the heck out of first and second with the 4.7 rear case, sometimes first and second with the stock front case is good (only 6" longer drivetrain BTW), and when I want total control and things happening nice and slow, no bounce, no sudden slide, nuttin' beats Marlin Ultimate low. I have gear combos that don't duplicate, and am good for snow bashin' to rock creepin', to towing a camper across Wyoming. It's all good.

Slap a ToyBox in there. You could even keep taller diffs and never feel constrained.

leiniesred
12-04-2007, 12:32 PM
I'm at about 244:1 in double low, 1st gear.
4.30st gear, x 4.7 x 2.28 X 5.29 = 243.7
My 3.0V6 (3vze) will also idle at 300 RPM. Just kinda wheezes along.

It is funny when you climb a rock, and the RPMs drop under 300, the dash floods with warning lights, but then the tire goes back down the other side and the revs come back up. Technically, I don't think the engine is "running" for a couple of seconds, but it is still turning over!

100:1 Makes the trails a lot easier. You can drive more smoothly. You can climb and descend rocks that you used to bounce over at 50:1.

As noted above, 100:1 means you are about 1/2 as fast as the majority of a group trail-ride. You wind up in 3rd or 4th gear on the trail, but you drop down to 1st and enjoy the lower gears at the rough spots like rock gardens, ledges and big climbs.

I find that wheeling with the club I'm in about 50:1 most of the time with 36 inch tires.

Above 200:1 is silly slow and can actually be a bad thing. Your wheels are all but stopped. No momentum to carry you over an obstacle you can't crawl. On ice, going slowly is one thing, but you might as well lock 'em up at 240:1. No control. Descending something sketchy is also a problem. You can't get enough tire speed to do anything if it starts to endo.

Having the CHOICE to go silly slow is really nice though. I often use the 244:1 ratio on the tough trails. but when the going gets REALLY tough I end up in 2nd or 3rd gear, double down(2.28*4.7), engine at 5K. That is about 100:1. I like to descend big ledges double down in 2nd. Right where you are looking.

I would say in summary that 100:1ish makes the rough parts of trails 2x easier/safer. It is also about perfect for tough obstacles that require tire spinning action.

Red_Chili
12-04-2007, 01:40 PM
Choice is good like ^^ said. It's like the dark side, once there you never go back.

One downside to be aware of is pushing in your clutch and freewheeling down a hill. More than one clutch has grenaded as its rotation exceeds 10K rpm or so. Rare, but possible. Once you are aware, it prolly ain't gonna happen.

bustanutley
12-04-2007, 02:41 PM
A low reving F with 100:1 and 40” tires is a good combination. I’m 67.5:1 and it is low enough most the time, but with 40s deeper gears are needed, a 4.3 atlas is in my future which will put me at 125:1, but most my wheeling will still be done at around 60:1. Most the obstacles in moab require a bump so deeper gears don’t really do much for you in that arena, unless you are running BFE.

It would be easier to keep my truck running on this obstacle with lower gears.
http://home.comcast.net/~utleyz/bvnotchsmall.JPG