camaro 69

hey guys I need a quick refresher course in Gear Ratios 101 .I have an x with the F 4.6 with a 17 tooth clutch bell.Question,the more teeth on the spur gear higher top end speed,fewer teeth more low end grunt?What would be the best all around spur gear?Thanks

gimp chump

The more teeth on the cluth bell = higher top end
fewer teeth on the spur = higher top end
and vice versa

RLMHPI

A very easy way to figure out gear ratios is by using the formula Driven over Drive or Driven gear Divided by the Drive gear!!
Eg. Driven is the spur gear lets say it has 47 teeth
Drive is the clutch bell lets say it has 13 teeth
If you divide 47 divided by 13 you will get 3.61 which is your gear ratio 3.61:1. Everytime your clutch bell spins 3.61 of a turn your spur will turn 1 complete turn if you dont believe me mark the gears and watch!! The higher the number the shorter your gear is. Its like first gear in a car lots of torque but no speed!! My trade school professor once taught me in a car you dont get something for nothing in first gear you sacrifice speed but have lots of torque to get the vehicle moving from a stand still as you switch gears you loose torque and gain speed the same goes for gear ratios in RC cars and trucks. The higher the number the shorter the gear = more bottom end less top speed the lower the number the longer the gear = less bottom end and more top end!!! Just count the teeth divide and you can tune gear ratios to perfection!!!! There are a lot of missunderstandings when it comes to gear ratios I hope i cleared this up for you !!!

cord arrow

The 4.6 will pull a lot of gear...not much on top, but pretty good down low.

If you choose more gear, for more speed, you really won't lose much on the bottom with this motor. That would be smaller spur / larger bell of course...

Spur divided by bell = gear ratio. I like numbers about 2.5 to 2.7 with this motor...it will pull these numbers. I've had other .28's that struggled to pull anything over 3.0 (which is really under), but boy would they go on top...

Polar_Bus

In regards to spur teeth count you have it backwards. The less teeth the higher top speeds, the more teeth, the less the top speeds will be.... (IN THEORY).

Every gearing change has both positive effects and negitive. Gearing is all a compramise of what you want your truck to do..... ie high top speeds, or hard acceleration. You can't get both, but you can compramise. With high tooth count clutchbells, you in theory should attain higher top speeds, BUT a Savage weighs 12 HEAVY lbs. A Savage also has a TON of "rolling resistance". You won't see top speeds much over mid 30's no matter what speed gearing you try (and many kids will start arguing over this mph claim).

The lower the teeth count on the clutchbell will yield much faster acceleration, and you will put a lot more power to the dirt. Your engine will rev much quicker also. A 17T clutchbell is too high IMO, and you are wasting your engine's power potential. I always suggest no more than a 16T bell. My preferreed is a 15T, as it seems to be the most fun, and versatile. I am not a fan of speed running a Savage, it's not what the truck was designed for, but again it's all your preferance. Good luck,

mazdab2600

this chart may help abit.
or a quick reference.

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My Feedback: (2)

I'm no kid or newb by any stretch of the imagination and will say with certainty that my Axial .28 Savage X SS will do better than mid 30's. (Clocked it with a real calibrated radar gun). And that's with a tire-shreading 18/47 gear combo.

Are those comments about a stock 4.6 or any engine?

The truck wheelies with almost no effort and flips over completely with mild effort. Any lower gearing on the CB would make the truck a pain to drive.

I'm going to try a 20t CB here soon to try and tame the wheelies.

bam.bam

Spur Gear/Clutch Bell Gear Ratio

Max Torque (Low End)
52/13 4.00
49/13 3.77
52/14 3.71
47/13 3.62
49/14 3.50
52/15 3.47
47/14 3.36
49/15 3.27
52/16 3.25
47/15 3.13
49/16 3.06
52/17 3.06
48/16 3.00
47/16 2.94
52/18 2.89
49/17 2.88
47/17 2.76
52/19 2.74
49/18 2.72
47/18 2.61
49/19 2.58
47/19 2.47
Max Speed (Top End)

Polar_Bus

Like I said, there is always people who will argue as far as top speeds. I have yet to see any credible data showing a savage can pull anything above mid 30's. I spent a years worth of high speed tuning, only to yield a top speed of 36 mph. And it took a LOT of chassis mods, NOT just a big ci engine. If you plan on using a 20T bell, better have a good performance carbon shoe'd clutch, or you will be frying clutches frequently.

Polar_Bus

Sorry this was a double post

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My Feedback: (2)

I'm not arguing with your OR the radar gun so we'll leave it at that. I guess video proof would be in order yes?!

I have an aluminum 3-shoe clutch setup with 1.0mm springs. That happens to only *add* to the wheelie frustration as it acts like a high-stall torque converter. The shoes hit so hard with no real in-between. Ah well live and learn.

Victorian Bitter

Good Info thanks Bam .

Cheers Dave.

Budda1224

Ya i bealeve the truck can go fast just like in real trucks it dosnt matter how big it is if you change the gearing it can go faster plus all the other stuff you can do to make it go faster
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