rusty_tlc
Dain Bramaged Member
X3, but it is sweet to have when you do need it.
what say you? crawl ratio
- Thread starter poor boy pulling
- Start date
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I am a noob to this, so if I have 33's, 4.10, stock 3sp TC, and a 4L65...I got 29:1. But it really is 58:1 because it is an automatic trans?
no, it is still whatever it is, but it will act as is it is a lower ratio due to the slip in the torque converter.
Ohhh gotcha..until the TCC lock up, then its 1:1
So my next upgrade should be an Orion with 4:1 Low
So my next upgrade should be an Orion with 4:1 Low
fj40charles
SILVER Star
That should be more than adequate for your little 33" tires. The torque converter will slip and can give you 2-3x or more multiplication.
58:1 is plenty for 33" tires and your engine.
If you end up getting an Orion, you'll be at 50:1 without torque multiplication. I think this would be too low unless you do very technical trails.
I'm at 45:1 without torque multiplication with 42" tires and it works fine for me. Low enough for control, but still have enough wheel speed in first gear when I need it.
Unless you have a manual lock up it will not lock at those low range speeds. A torque converter is basically just a big centrifugal clutch, well not really, but kinda sorta... ish...
at full lock like on the freeway the converter is at 1:1 as it isnt slipping. but at lower speeds it will have some slip to it when not locked up. your crawl ratio is the 29:1 but it simulates having a lower crawl ratio from the slip in the converter, kinda like on a manual with gears not low enough you have to play with the clutch a lot when in some of the more technical stuff.
yours doesnt?
I agree with this.
leave the 4:1 out until / if you go to bigger and badder rubber.
rusty_tlc
Dain Bramaged Member
The torque converter is more like two fans positioned close to each other with a vicious fluid surrounding them. When the engine turns one fan the fluid moves and transfers power to the other fan. The fans have a s*** ton of blades and are really close together so this all works out without a huge inefficiency.
At least that's how my simple mind understands it.
At least that's how my simple mind understands it.
Go back to post #24 and follow and read the linked material. This sure made a difference in how I understood torque convertors.
Don
Don
As most have already stated...
Im running a 3.4, auto, dual mini's, with 156:1 on 37's (plus the TC). I rarely use 156:1, only in big rocks or to play walk the crawler. The 5:1 gear is plenty for most things. If I had to build new cases id run 2 stock mini's.
Im running a 3.4, auto, dual mini's, with 156:1 on 37's (plus the TC). I rarely use 156:1, only in big rocks or to play walk the crawler. The 5:1 gear is plenty for most things. If I had to build new cases id run 2 stock mini's.
Sweet, thanks for the info guys. I was just curious. Knowing is half the battle.
what's the total length on that setup?
Not sure, but I had to cut off 1in of my back DS.
pb4ugo
SILVER Star
In my 40 I have, SM420 X dana model 20 w/frt dig X 4.88=84.63:1 in low 1st gear. 35" tires w/a hybrid centered rear. It's cheap, short & effective.
Hey Poor Boy Pulling! i'm not sure if your still looking at the auto tranny option but i have a 3speed case with the th350 adapter already bolted to it. So all you would need is a th350 with a 6in output shaft and bolt it up and go. i'm only looking to get 300.00 for the adapter and case. just throwing it out there. thanks for your time
keith
keith
Just to throw this in the pot, here's my SM465 to single Toy T case set up by Marlin with Toybox adapters and 4.7:1 low gear. It measures in at around 32" overall. Im running retubed toyota pickup drive shafts and 4.37 Mini Truck axles with flipped springs SOA on 35's. Using a double cardan in the back.
so do yall think a crawl ratio of 30.58:1 would be acceptable with a automatic? it should feel like 61:1 with a manual from what i've read here?
i am seeking that mythical perfect ratio that will work best for me for racing and trailriding. i just ordered a 3:1 atlas that, coupled with a th400 and 4.11 gears in the axle with 40" tires will give me that 30.58 crawl and a top speed of 58 mph without having to shift out of low in the t-case which should be pretty sweet for racing around here and for point and shoot stuff. i'm just not too sure about crawling?
i am seeking that mythical perfect ratio that will work best for me for racing and trailriding. i just ordered a 3:1 atlas that, coupled with a th400 and 4.11 gears in the axle with 40" tires will give me that 30.58 crawl and a top speed of 58 mph without having to shift out of low in the t-case which should be pretty sweet for racing around here and for point and shoot stuff. i'm just not too sure about crawling?
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A 3:1 or 3.8:1 atlas is the way with an auto, but with axles geared for big tires. Give the truck the ability to actually move in high and go from there. A 3:1 tcase with an auto and 5.29s on 40s should be pretty money.
I've got a 700r4, atlas 5:1, 4.56 R&P and 42in tires, Crawl ratio of 69.77 in low range.
Works real good
Works real good
how real is the 2:1 torque multiplication thing with an auto? does it depend somewhat on the stall of your converter?