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Got Arbutus?
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Discussion Starter · #1 ·
well as it states, both will leave me with the same rear driveshaft angle and are equally involved. however the 220:1 option will cost a little more (around 400 bucks) so do you guys think it is worth it?
 

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You are putting a V8 in right? Consider the torque you are putting to the rear axle. It could end up being very significant, especially if you need to bounce on the gas.
I think the only reason the Toyota rears last when they do crawl ratios like that is cause they do not have the same large torque numbers.

So my suggestion would be to do some reasearch and find out what kind of torque numbers you will end up putting out with the reduction boxes to the rear axle. And then find out if the 9" and its components (you full floatered it right?) can handle that amount of torque.

Good Luck.
Wes
 

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Hey Wesley we all realize that with double low gearsets etc you will not use the gas pedal at all.

Even the original six cylinder would blow chunks out of the axles at 160:1 if you bounced the gas pedal.
 

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Superfly
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You're talking about dual cases and a manual tranny, right? You might as well go 220:1, just so you can say you have it. :D

Besides, you don't HAVE to use the lowest ratio. Just use it when you absolutely need it.

...lars



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220:1 for sure if its only an extra 400.00 you would be stupid not to.
just think to every time someone has said oh i wont need this, the very next time out you need it.
 

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Superfly
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Re: Fess up, Andrew

cwate said:
I'm guessing the 160:1 is NP435/NP203/D300
What's the 240:1? 3:1 gears in the 203, or something completely different?
The crazy bastitch was talking about a tranny, two tcases, AND an underdrive. ie: tranny, 2 crawler boxes, tcase

...lars



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Andrew, one thing to think about is stopping. When I was down at Naches with Dale we were talking to a guy with a 4:1 klune, 205 and a 6.69 first gear and 4:88's = 255:1. He rarely runs in low-low-low because he can't stop without pushing in the clutch.

JP
 

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Discussion Starter · #12 ·
keep guessing.....


also i am thinking of going 220:1 and what is really funny is that for an extra 1000 i can toss a 4:1 in the d300 and get over 500:1!!!!!!!!! so when should i draw the line?
 

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Superfly
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AndrewH said:
also i am thinking of going 220:1 and what is really funny is that for an extra 1000 i can toss a 4:1 in the d300 and get over 500:1!!!!!!!!! so when should i draw the line?
It's your money...so in my mind, there is no line.

My own experience has been that my 43:1 ratio (factor in the torque converter and you get 86:1) is pretty good but that's with an automatic. I'd guess that anything between 100 and 200 to 1 will be just fine for 99.99999999% of rockcrawling situations. You may want deeper gears if you decide to go down the Lion's Back, though. By hell, even people with automatics drive down that! So if you want a conservative answer, then stay with the 150:1 range. It'll do ya just fine.

...lars



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I think you should do the motor swap and then decide if you need more crawl ratio. Having wheeled with you a few times and knowing that you've got about the same crawl raito I do (78:1) I'd say a motor swap will make a huge difference. You seem to spend a lot more time on the clutch or fighting the motor than I do. I'm pretty sure it's not my awesome driving :rolleyes: that makes the difference. I can let the clutch out and idle along at 4-500 rpm. Your Jeep doesn't seem to have the same low end grunt. Next time we're out, take mine for a spin and see what you think.

With my current crawl ratio I've found that it's too low to go down hill (I always end up shifting up or giving it gas to stop the Jeep from sliding). For crawling over stuff I rarely feel the need (maybe 10% of the time?) go lower. After reading all the posts on other boards, the popular opinion seems to be that anything over 100:1 with a V8 is breakage waiting to happen.

I've got plans to add an NP203 reduction box but it's more because I want something in between my 1:1 high range and my 2.62:1 low range for running gravel roads. I doubt I'd use the 156:1 very often but the 60:1 would definitely get used a lot.
 

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Discussion Starter · #17 ·
well ya you have a really good point jon. i am doing the 5.0 swap at the same time so i figured i would just add a little more reduction at the same time. i have to agree with you on the fact that if you run a 4.0 down to 500 rpm it will stall out on you so that is another reason for a V8....i want that low end torque that a 6cyl will never be able to give out.

if i do go with 220 then i will have a choice of 50:1, 80:1, 95:1, 125:1 and then 220:1 depending on the different tranny gear and t-case gear combo.
 

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AndrewH said:
....i want that low end torque that a 6cyl will never be able to give out.
Actually a six cyl has almost as much torque when compared to a equally sized V8...

The Ford 300 Str8 6 produces almost as much torque as a Ford 302 V8

1994 4.9L(300 ci) 150 hp @ 3400 rpm 260 ft/lb @ 2000 rpm MPFI

1994 5.0L(302 ci) 185 hp @ 3800 rpm 270 ft/lb @ 2400 rpm MPFI

It produces torque at lower RPM's

In 2002 GMC reintroduced an inline 6 with 4.2L displacement that produced nice numbers

Horsepower = 270 @ 6000 RPM, Torque (lb-ft) = 275 @ 3600 RPM

As compared to their small 4.8L V8

Horsepower = 270 @ 5200 RPM, Torque (lb-ft) = 285 @ 4000 RPM


Really not much difference!:read
 
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