Revo Gearing

[richpadg]

I need opinions on the best gearing for racing on a short track consisting of red dirt. Right now I am using 15/40 and it seems most other trucks run up on me in the straight. I am also using the stock 2.5r which has been modified. Tranny is FOC with Close Ratio. 30k front and back in diffs.

Any input is appreciated.

Thanks

[Batfish]

Welcome to the forums, Richard!

I don't run a Revo myself, but in general a larger pinion/clutch bell will give you a higher top speed. You may want to consider a 15 or 16 clutch bell. You'll sacrifice a little of the low-end torque in exchange for the top speed, but it may still suit the track you're on.

RC-Monster Mike does run a Revo, so hopefully he'll pipe in here and offer some advice.

[RC-Monster Mike]

Rich,

Are the other trucks catching you because you run out of speed, or are they accelerating faster? I am guessing you should have pretty nice acceleration with the setup you are running(close ratio, FOC, 15/40 gearing). If you are not having any acceleration issues, but a top speed issue, I would drop in a larger clutch bell(16 or 17) or a smaller spur(36) or both, depending on where you are at a disadvantage. The RDLogics top end pipe also works very well with the 2.5R motor and really brings some power out.
Welcome aboard as well!

[richpadg]

The straight isn't really long enough to hit top speed, it's really more of an acceleration problem I guess.

[squeeforever]

then i would go with a smaller clutch bell.... with a 14 tooth clutch bell and a 40 tooth spur you can get 20.33 to 1 gear ratio in second gear.... look at your manuel that came with your revo; on page 45 there is a chart with all the gear ratios with 14,15,16 tooth clutchbells; 36,38,40 tooths spurs; and standard, close, and wide ratio gears...

[richpadg]

Here's a video of one of the races at the track. This will give you a good idea of how the track is set up. Pretty small track, with tight turns. Able to pull off 16sec lap times.

Track Layout

Thanks for all the help

[richpadg]

Originally posted by squeeforever
then i would go with a smaller clutch bell.... with a 14 tooth clutch bell and a 40 tooth spur you can get 20.33 to 1 gear ratio in second gear.... look at your manuel that came with your revo; on page 45 there is a chart with all the gear ratios with 14,15,16 tooth clutchbells; 36,38,40 tooths spurs; and standard, close, and wide ratio gears...

I don't really understand what those numbers mean. Can you explain? The lower the number the better?

[RC-Monster Mike]

How is the slipper setting? if it is too loose, it will hurt acceleration. Otherwise, gearing down is the option(or replace the motor). Drop a tooth on the clutch bell, make sure the slipper is tight and possibly install a better pipe(LMK if I can get you anything, obviously). Small track there. Definately don't need top end.

[richpadg]

Originally posted by RC-Monster Mike
How is the slipper setting? if it is too loose, it will hurt acceleration. Otherwise, gearing down is the option(or replace the motor). Drop a tooth on the clutch bell, make sure the slipper is tight and possibly install a better pipe(LMK if I can get you anything, obviously). Small track there. Definately don't need top end.

Slipper is fine, I can barely turn it by hand. The motor is practically brand new and modified, has very good compression. I was using the Trinity pipe, but don't have a stinger for it, so I switched back the stock pipe. Pretty loud without stinger. So, do you suggest going to a 14t clutch bell and sticking with the 40t spur?

[RC-Monster Mike]

Yes, I would get a smaller clutch and stick with the big spur. How did the trinity pipe perform? Noise is something you have to live with. Performance is what you want in the end, though.

[richpadg]

I didn't seem to have any problems with it. Didn't notice much of an increase in speed though. Do you recommend a different clutch than the stock setup?

[richpadg]

Any opinions on this type of clutch?

Clutch

[RC-Monster Mike]

I haven't had any trouble with the stock clutch. Changing the clutch won't make you faster unless the clutch is slipping excessively, which is unlikely.

[squeeforever]

so what would the advantages to having a 3 shoe clutch rather than the stock 2 shoe?

[coolhandcountry]

I would try to tighten the slipper up a touch and try that to. If the gear doesn't seem to do much.