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t 350

Ok. How do i figure out what my final drive will be with a 4.7 to 1 case and 4.10 gears with 39.5s?
 
2.52 X 4.7 X 4.1 = 48.56

Tire size does not mean anything in the equation. The only thing tire size does is how FAR you travel on one revolution of the tire. The bigger the tire, the farther you travel per revolution.
 
KarlVP said:
2.52 X 4.7 X 4.1 = 48.56

Tire size does not mean anything in the equation. The only thing tire size does is how FAR you travel on one revolution of the tire. The bigger the tire, the farther you travel per revolution.
Click to expand...

Thanks Karl.:;
 
Brian H said:
Ok. How do i figure out what my final drive will be with a 4.7 to 1 case and 4.10 gears with 39.5s?
Click to expand...


Your crawl ratio is 2.52x4.7x4.1= 48.56

crawl ratio is 48.56:1

Your final drive would be trans at 1:1 t-case at 1:1 an diff at 4.1:1

final drive ratio is 4.1:1
 
That number is kind of misleading because it only represents the effective gear ratio of the transmission when it's locked up so to speak. If you're comparing that to a standard transmission that's the gear ratio with the clutch fully released. In the Turbo 350, depending on the shift kit you have, the lock up is around 2500 or 3000 rpm, so if you're running RPMs lower than that, you are riding the clutch so to speak, lowering your effective gear ratio.

I've heard that on the TH 350 (I'm running the same transmission) is about 6:1 coming off idle (someone gave me that number as the effective gear ratio coming off idle).

I'm running TH305-NP203-NP205 and look at those ratios as 6:1-1.98:1-1.98:1-5.38:1 = 126.5:1. If I compare the speed of the vehicle at idle vs my old 5sp with a crawler setup at 226:1 it seems pretty realistic. Using the2.52:1 ratio my crawl ratio is only 53.1:1 and I know that the effective gear ratio MUCH lower than that.

Brian, you'll find that crawler ratio almost TOO low except for extreme circumstances. I only double down to either play around and show off a little or in very sticky situations where slow is the way to go.

The nice thing about running the crawler setup is that your transmission will spend more time locked up which helps it run cooler. You will find that if you're in low, you're running high RPMs just to keep moving on the trail. While a noisy rig is fun for play, running around with a healthy V8 running through a dual 40 series flowmaters can be pretty annoying at 3000+ rpm all day.
 
Gibby said:
That number is kind of misleading because it only represents the effective gear ratio of the transmission when it's locked up so to speak. If you're comparing that to a standard transmission that's the gear ratio with the clutch fully released. In the Turbo 350, depending on the shift kit you have, the lock up is around 2500 or 3000 rpm, so if you're running RPMs lower than that, you are riding the clutch so to speak, lowering your effective gear ratio.

I've heard that on the TH 350 (I'm running the same transmission) is about 6:1 coming off idle (someone gave me that number as the effective gear ratio coming off idle).

I'm running TH305-NP203-NP205 and look at those ratios as 6:1-1.98:1-1.98:1-5.38:1 = 126.5:1. If I compare the speed of the vehicle at idle vs my old 5sp with a crawler setup at 226:1 it seems pretty realistic. Using the2.52:1 ratio my crawl ratio is only 53.1:1 and I know that the effective gear ratio MUCH lower than that.

Brian, you'll find that crawler ratio almost TOO low except for extreme circumstances. I only double down to either play around and show off a little or in very sticky situations where slow is the way to go.

The nice thing about running the crawler setup is that your transmission will spend more time locked up which helps it run cooler. You will find that if you're in low, you're running high RPMs just to keep moving on the trail. While a noisy rig is fun for play, running around with a healthy V8 running through a dual 40 series flowmaters can be pretty annoying at 3000+ rpm all day.
Click to expand...

Well ill be running a healthy 350 turbo 350 and 4.7 case. From what I get out of this is my crawl ratio is more than enough for what I have?
 
Did you go with the twin stick setup? I LOVE front wheel digs when you've got a big rig. I use it a LOT when running the Busy. It took me a while to get the hang on shifting the twin stick but now I have it down.
 

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