40 Series TC Gearing

[aham2003]

Question. I am about to start my dingo build. I am going with a powerland 420 with stage 1 mods. I am looking at sprockets for the TC. I want a good balance of torque and top speed. It has 18" tires and a 54 tooth sprocket. If I went with a 12 tooth sprocket that would be a 4.5 ration with a top speed of 64 MPH at 5400 rpm. Is that ratio doable? How would the kart perform? I know everyone's safe haven is a 6:1 ratio, but would this be acceptable to run? If not, I will knock it down to a 10 tooth for a 5.4:1 ration.

Opinions/suggestions are welcomed and wanted.

 

[Poboy kartman]

4.5 might work...but it may be hard on belts. 5.4 sounds doable.

 

[aham2003]

I was thinking the same thing about the belts. Ill probably go the safe route and do 5.4.

Also, is this a reputable seller? Anyone ordered this 40 before?

http://www.ebay.com/itm/GO-KART-TOR...313290?hash=item211744eaca:g:2usAAOSwPCVX4fFH

 

[Joe-405]

Hmmm that user name and 97% feedback has me worried a little bit. That and I don't see phone number so I personally wouldn't use them. But you should still be ok maybe.

 

[ezcome-ezgo]

Just pulleys, no belt.

 

[aham2003]

I am using this motor mount plate with the jack shaft so I will have to measure and drill holes in the plate before I know distances for what belt to order. Plus, it saves me from welding a new plate onto the kart. Its a 285 Dingo so the 420 wouldn't bolt up right anyway.

http://www.bmikarts.com/Motor-Mount-Plate-with-Jackshaft-and-Bearings_p_1051.html

 

[bob58o]

I am going with 60:11
5.45 : 1 with 18.5" Tires.
40 series TC

3100 RPM = 31 MPH
5000 RPM = 50 MPH


I think your 4.5 should be ok too.
I actually want to gear for more torque but trying to keep RPMs low with the stock rod and Torque converter belt transmission.
Have you checked out kartcalc.net on your mobile device?

 

[landuse]

5.4 would be better for you. 4.5 is a bit high

 

[aham2003]

I am going with 60:11
5.45 : 1 with 18.5" Tires.
40 series TC

3100 RPM = 31 MPH
5000 RPM = 50 MPH


I think your 4.5 should be ok too.
I actually want to gear for more torque but trying to keep RPMs low with the stock rod and Torque converter belt transmission.
Have you checked out kartcalc.net on your mobile device?

I did. Told me 4.5 was too high and could cause damage to the belt and/or tc.

 

[Whitetrashrocker]

For what it's worth I clocked my dingo go at 40mph per my phone GPS.
Vanguard 9hp, no gov.
Series 40 tc
9t on the js, 54t axle.
18" tires

Sorry no tach.

 

[bob58o]

For what it's worth I clocked my dingo go at 40mph per my phone GPS.
Vanguard 9hp, no gov.
Series 40 tc
9t on the js, 54t axle.
18" tires

Sorry no tach.

Well Mr Whiskey Tango Romeo.....

Do tell? Is the acceleration everything you want?

 

[Whitetrashrocker]

That's a deep subject Bob. Kinda wet too.

Not really. I want all torque. I want to drift the thing everywhere. The top end is nice but the brakes suck and there's no slowing down for turns at that speed. And where I'm at the terrain in very rocky and makes for a rough ride.

 

[aham2003]

For what it's worth I clocked my dingo go at 40mph per my phone GPS.
Vanguard 9hp, no gov.
Series 40 tc
9t on the js, 54t axle.
18" tires

Sorry no tach.

Only 40? Im hoping for at least 50. Bet the thing pulls the front tires off the ground though lol

 

[Whitetrashrocker]

I'm on dirt so it just spins the tires. It will bark the tires if I take off from the concrete but no wheelies.

---------- Post added at 10:32 AM ---------- Previous post was at 10:29 AM ----------

I was hoping for around 50mph too.

I tried some 22 inch tires and found I could only get to about 35mph. Go figure. Larger diameter makes 12.5 inches per revolution. Faster I thought. Well I'm guessing the weight difference between the tires had some effect.

 

[aham2003]

The calculator is telling me to expect 54 MPH with 5.4:1 gearing.

 

[Whitetrashrocker]

Only way to really find out is to do it.

 

[aham2003]

Only way to really find out is to do it.

Its being done. Lol.

 

[OzFab]

I tried some 22 inch tires and found I could only get to about 35mph. Go figure. Larger diameter makes 12.5 inches per revolution. Faster I thought. Well I'm guessing the weight difference between the tires had some effect.

Nothing to do with weight, that's all about gearing (trust me, read on)...

If possible, run that test again, on the two different sized tyres & measure the peak RPM of the engine; I can almost guarantee the engine RPM with the 22" tyres is lower than with the smaller tyres...

That's because the rolling mass (the rear tyres) is harder to turn, simply due to the added circumference so, the engine can't reach its peak; absolutely nothing to do with weight...

I believe this is the point being made in this thread...

 

[Whitetrashrocker]

Ozfab, I don't need to rerun the test. I can say for sure the top end Rpm's were not there with the larger tire.

That's kinda what I was getting at. A chart only can tell you so much. Real world testing is different. A chart can't factor in all the variables.

 

[bob58o]

Physics is a simulation of approximations.