Gear ratio

[xengxue]

Ok so I got a new spur gear since my stock plastic one melted. So i got a steel 72 teeth spur gear and wanted to get a 22 teeth clutch bell. So the question is what should my new differentiation be.

 

[Greywolf74]

So i got a steel 72 teeth spur gear...

/sadpandas

So the question is what should my new differentiation be.

Not sure I understand the question.

 

[xengxue]

I was told if I get a 22 teeth clutch bell I would need to change my drive train gearing and was wondering what it should be changed to...make more sense.

 

[Greywolf74]

Well, i dont know what kit you have but most kits dont have many options (if any) to change any of the gearing except the clutchbell and spurs. Again not sure what kit or engine you have but a 3.2:1 spur/clutchbell ratio doesn't see terribly low to me that you would need to change anything else.

 

[xengxue]

i got the traxxas nitro sport with a 72 teeth spur gear and a 12 teeth clutch bell with a 3.3 on it. besides the spure gear nothing else is upgreaded because i just got the new engine on it. before i threw it on there i read that everything else would be ok. but the guy at hobby town told me if i was to throw a 22 teeth clutch bell i would need to change out my drive train gaering because i would be to much power for my stock gearing.

 

[Greywolf74]

Torque is what tears up your gears and by raising your clutchbell tooth count your actually reducing the amount of torque your kit will put out. Maybe someone will correct me here but I dont think that guy knows what hes talking about. Traxxas doesn't even make other sized gears for the nitro sport transmission. If anything is gonna tear up your transmission gears its gonna be the extra torque from a 3.3 engine. Putting a high tooth count clutchbell on it though will actually reduce the amount of torque the engine is placing on the transmission so if anything Id say that adding a high tooth count clutchbell helps offset the extra torque put out by a 3.3 engine. The 3.3 though really isnt all that much bigger (I mean it is a nice jump in performance but its not rediculous) than the 2.5 though. Your talking a .15ci engine versus about a .18 or .19ci engine? Id say if you have to worry about anything its gonna be your stock drive shafts. You'll probably break those at some point and if you do Id replace them with some MIP steel ones.

 

[xengxue]

That's what I was told about the transmission too...but I thought higher teeth on the spur gear equals faster top speed or am I wrong

 

[Greywolf74]

That's what I was told about the transmission too

I wouldnt worry about the transmssion the stock clutchbell is already a 20T, going up 2 teeth is hardly gonna make much difference. If something breaks you can worry about it then but as far as I know they dont make alternate gears for a nitro sport transmission anyway. and just a word of advice, loose the steel spur gear...if you tear up anything its gonna be a plastic spur gear instead of the transmission...if you have a steel spur though then if something breaks it will be in the transmission. Most people will agree that its better to tear up a 4-5 dollar sput gear instead of a transmission.

but I thought higher teeth on the spur gear equals faster top speed or am I wrong

that is correct...bigger cluthbell equals higher top speed....higher top speed equals lower torque on the bottom end....torque is more likely to tear up your transmission than top speed.

 

[SchrodeMode]

That's what I was told about the transmission too...but I thought higher teeth on the spur gear equals faster top speed or am I wrong

This gearing info is wrong, more teeth on the CB/pinion will give more speed, more teeth on the spur will give more torque.
CB/Pinion - + teeth = Top end speed, - teeth = Low end torque
Spur - + teeth = Low end torque, - teeth = Top end speed

You'll want to replace your idler gear in your transmission, the Rusty has a plastic one, but the steel one (part # 4496) from a Nitro Slash will fit. You'll also want to replace your drive shafts, again the N. Slash has HD ones (part # 6852X) that are a direct replacement for the Rusty's. I'd also look into doing the wide mod and front hex conversion as well, the wide mod will help with handling and the hex conversion will open up your wheel options. Doing them both will allow you to run the same offset wheels on the front and rear, this will allow you to rotate your tires instead of having bald rears and like new fronts.

 

[Greywolf74]

Yeah shrode is right about the tooth count on the spur...For some reason when I read that sentence I read clucthbell for some reason instead of spur which would have been correct. sorry for confusing you...

The steel idler gear is a good idea too...I forgot the original one was plastic...my rusty I bought used and it already had a metal idler gear. and i forgot about converting the front to hexs...thats a definite must have there too IMO.