Torque converter instale. Gearing questions

[Kleyny]

Hi OldMiniBikes.
I just purchased a tav 30 Chinese copy with a 10 tooth sprocket. For my off road go kart.
So at the moment my gear ratio is 4.8:1(10 drive sprocket and a 48 wheel sprocket) with a 13" tire.
Driver and kart weighs roughly 370ish lb. At the moment on hard ground it hits the 4500 max rpm easy enough ( not do much on the softer Sandy ground)
Question 1: do you think the torque converter belt will handle the extra rmp/hp?
Question 2: is with the torque converter running the same gearing do you think I will still hit top rpm with the od? As the ratio I'd going to be less than 4.8:1. Or should I get a 9 tooth sprocket?

Thanks
Neil

 

[yalipito]

On my mini I was never able to reach high rpm with the od. My engine was a B&S animal built like a WF and the bike/rider was half the weight of your kart. I also tried the 9 tooth with no real change. I still run the original belt that came with it. The tav now powers a golf cart and the belt is still ok.

 

[Kleyny]

Any idea of your gearing yalipito?

 

[Kleyny]

Any idea of your gearing yalipito?

 

[super nate]

the six inch pulley makes a 9% overdrive and the motor cant pull past it. I use a 30 series converter with a seven inch pulley. it doesn't have a overdrive and goes one to one. my engine reves to 7700 no problem. now on a cart it will depend on what size tire diameter your using and gear. it might work , but the weight is going to be a issue. need more info on your setup to help, tire diameter and gearing you have

 

[yalipito]

Any idea of your gearing yalipito?

I don't have it on the mini anymore but I think it 10 out of tav to 36 on rear, 16" rear tire. It would hit 60 mph at around 8k.

 

[Kleyny]

the six inch pulley makes a 9% overdrive and the motor cant pull past it. I use a 30 series converter with a seven inch pulley. it doesn't have a overdrive and goes one to one. my engine reves to 7700 no problem. now on a cart it will depend on what size tire diameter your using and gear. it might work , but the weight is going to be a issue. need more info on your setup to help, tire diameter and gearing you have

Its all in my first post.
10 tooth on the TC 48 tooth on the wheel, tire is 13" and the kart and rider at about 350-375ish.
at the moment with the normal clutch i hit my limiter (around 4500) fairly easy

Neil

 

[Harleys Papa]

You will be fine but I would get a Comet belt and throw that China one right in the trash :thumbsup: I run a China TC on my race trike with a 9 to 46 and have no problem, I'm pushing 11h with no gov :scared: Oh I am 180lb and the trike has got to be over 150lb :shrug:

 

[Kleyny]

Cool trike Harelys Papa.
Hopefully it works as good as yours.
Going to go to my local belts supplier and hopefully I can match it with a Gates one

 

[Possom point]

the six inch pulley makes a 9% overdrive and the motor cant pull past it. I use a 30 series converter with a seven inch pulley. it doesn't have a overdrive and goes one to one. my engine reves to 7700 no problem. now on a cart it will depend on what size tire diameter your using and gear. it might work , but the weight is going to be a issue. need more info on your setup to help, tire diameter and gearing you have

What length belt are you running? Or do you have a part number? My TC is a 30 series with the yellow spring, and it's not revving to we're it needs to be at RPM wise....

 

[super nate]

30 series torque converter with a 7 inch pulley uses comet belt # 203591.

 

[Possom point]

30 series torque converter with a 7 inch pulley uses comet belt # 203591.

Awesome. Thank you!!!!

 

[San Diego]

Super Nate: What gears are you running on the TC & the rear wheel, tooth count?

Are you running a cover over your TC?

 

[super nate]

the 7 inch pulley will not allow you to run the stock cover for your tc you will have to modify it or cut the back section off. my 212 has 13/70 sprockets also I have the heavier garnter springs in the driver with the pulley spring wound tighter. thing launches at 4100 on the bars!

 

[yalipito]

On my mini I was never able to reach high rpm with the od. My engine was a B&S animal built like a WF and the bike/rider was half the weight of your kart. I also tried the 9 tooth with no real change. I still run the original belt that came with it. The tav now powers a golf cart and the belt is still ok.

Belt just crapped out after 12 years. I guess I can't complain. If anyone knows of a better belt than stock let me know please, otherwise I will buy a stock one. Thanks

 

[super nate]

try beltpalace .com

 

[2strokd]

How long are the comon belts in this application? The scooter CVT belts are real tough, and some made with kevlar even.

 

[Kleyny]

How long are the comon belts in this application? The scooter CVT belts are real tough, and some made with kevlar even.

I think you will find most scooter belts are symmetrical the Tavs are Asymmetrical.

 

[2strokd]

All of my scoots use two dfferent sized pulleys. Depends on the purpose of the setup as to which pulley is bigger is. performance (speed) uses a larger rear pulley where the simple (aka economy minded) will have symmetrical or a larger front pulley. I will get the measurements from a Short Case 2t belt for comparison. My Helix has a larger rear pulley, but my China 250 is symmetrical. The Beamer has an Over Range rear pulley which is what it seems is called Over Drive in MB land

 

[Kleyny]

Its the belt itself that a Asymmetric not the pullies. Asymmetric belt has one flatter side and one angled side, a symmetric belt has two angled side hence the V.