Gokart project....

[Kmukum]

I'm in a go kart project. Our team is using 125cc 3hp Briggs and Stratton engine. I'm confused that what transmission to use? And is that better to use centrifugal clutch alone??
Please help me guys.....!!!!

 

[tinamcjittles]

I'm in a go kart project. Our team is using 125cc 3hp Briggs and Stratton engine. I'm confused that what transmission to use? And is that better to use centrifugal clutch alone??
Please help me guys.....!!!!

Homemade go karts don't generally have gearboxes because they are difficult to make work with whatever engine you may have. No it isn't better to use just the clutch, but its much easier.

Edit: Yes thank you OzFab I changed transmission to gearbox so that your salty OCD can calm down

 

[Flyinhillbilly]

A torque converter is more it less like an automatic transmission for small engines. Probably just what you need.

 

[OzFab]

Homemade go karts don't generally have transmissions because they are difficult to make work with whatever engine you may have. No it isn't better to use just the clutch, but its much easier.

Again, you're posting incorrect information; a cent clutch, chain & axle sprocket is a transmission as it transmits engine power to the drive wheel(s); any mechanism that transfers engine power to the drive wheel(s) is a transmission...

Kunga, my daughters kart had a 3hp engine... & 12:1 gearing to make it move; much less than that & it won't be going anywhere (power:weight ratio & all that); BTW, with that gearing, it had a top speed of ~10mph...

DO yourselves a favour & shell out $100 for a 212cc Predator, you'll be glad you did...

As for transmission, a centrifugal clutch will do but, a torque converter will be much better...

Tell us more about the kart; is it for road/track use or offroad?
What size is the kart?
What size are the rear wheels?

 

[Kmukum]

Thank you for your kind reply ozfab. We are building it for track....
Can I get better performance by using CVT rather than centrifugal clutch??

 

[KartFab]

Thank you for your kind reply ozfab. We are building it for track....
Can I get better performance by using CVT rather than centrifugal clutch??

torque converter > cc from 0-3600 rpm with lots of lower speed deceleration/acceleration
centrifugal clutch > torque converter at sustained rpms (like go kart racing) so that is why you see clutches on virtually all racing karts as they have little to no power transmission loss, whereas a torque converter would suck on such a small engine due to parasitic drag.

Id be one of the first to say a torque converter is almost always better than a centrifugal clutch, which is true for just putting around and climing hiills, but if you are just looking at racing, then the centrifugal clutch wether it be a shoe, or disc clutch, is going to be much better performing than a torque converter.

best performing would be a disc type clutch (bully, or noram cheetah, with engagement rpm set lower if you arent going to modify the engine- which is kind of a junky engine to begin with).

Next best and cheaper would be like a noram GE or a heavy duty racing shoe style centrifugal clutch

cheapest/least best performing would be any old centrifugal clutch like a max torque, or $20 ebay one.

More expensive clutches will give you excellent launch, and highest performance when accelerating/decelerating, but they will all perform pretty close when they arent under a lot of stress from acceleration and deceleration.

 

[Kmukum]

torque converter > cc from 0-3600 rpm with lots of lower speed deceleration/acceleration
centrifugal clutch > torque converter at sustained rpms (like go kart racing) so that is why you see clutches on virtually all racing karts as they have little to no power transmission loss, whereas a torque converter would suck on such a small engine due to parasitic drag.

Id be one of the first to say a torque converter is almost always better than a centrifugal clutch, which is true for just putting around and climing hiills, but if you are just looking at racing, then the centrifugal clutch wether it be a shoe, or disc clutch, is going to be much better performing than a torque converter.

best performing would be a disc type clutch (bully, or noram cheetah, with engagement rpm set lower if you arent going to modify the engine- which is kind of a junky engine to begin with).

Next best and cheaper would be like a noram GE or a heavy duty racing shoe style centrifugal clutch

cheapest/least best performing would be any old centrifugal clutch like a max torque, or $20 ebay one.

More expensive clutches will give you excellent launch, and highest performance when accelerating/decelerating, but they will all perform pretty close when they arent under a lot of stress from acceleration and deceleration.

What do you think about using 3d manual clutch ???

 

[Kmukum]

Thank you rail rider...
Yeah you are correct I'm in a contest. That contest is for all speed, distance on a tank of gas.....etc...

 

[bob58o]

You'll never pass tech inspection if you don't tell us the rules.
And we, as a forum, collectively failed if you don't win this thing.

 

[Kmukum]

Thank you guys happy to hear that you are to support...
I'll just get you guys the rule book of the contest....

 

[Flyinhillbilly]

IMO you should also pay especially close attention to the alignment of the front wheels, and the preload on the bearings. As has been previously stated, less tooling resistance equals less wasted energy. If you are allowed to adjust the timing you may want to experiment with that as well as jetting the carb on the lean side to get the maximum efficiency out of it.

 

[Flyinhillbilly]

I can't stop thinking 12" bike tires with a smooth tread for the front end.

Maybe on all four corners. Less rolling resistance, and less drag through the air. I don't usually split hairs on things like this, but being an efficiency challenge I think every little bit will count. Maybe even make it a lay down style to get the rider out of the wind and reduce drag.

 

[courts94s]

I can't stop thinking 12" bike tires with a smooth tread for the front end.

The most common bike skewers is 9mm (diameter). That's just under 3/8 inches. That's a very small bolt for any amount of weight. It works on a bike, because the weight is distributed to both sides.

Sent from my iPhone using Tapatalk

 

[courts94s]

heres a little thinking I've done about this project...... working on the back now.. Those will be easy.

People will think you're crazy... but Van Gogh was crazy, so do what makes you happy. A CT90 wheel might work a little better. It will be more expensive than a bicycle wheel, but what good is money, if you don't spend it.


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[Flyinhillbilly]

Oldie but a goodie
https://m.youtube.com/watch?v=jZf695rtmNM

 

[Kmukum]

By

Now we are talking... They have bike chain cent clutches maybe add a derailer and a 7 pack of gears. And a coroplast body (old election signs)



---------- Post added at 11:15 AM ---------- Previous post was at 10:43 AM ----------

Has any thing been built yet?

Not yet.......

 

[Flyinhillbilly]

I really want to see the rules. I just woke up in the middle if the night thinking about ethanol vs non ethanol fuel (I get obsessive about competition, that's why I had to quit racing). Non ethanol fuel will provide about 3-5 percent more energy per unit if you're allowed to use it.

 

[Kmukum]

These are the rule guys......

 

[Kmukum]

Also this.........
Our team also came up with a design, I'll just send it

 

[Kmukum]

Ethanol is a scam on our ag.fields and our vehicles well being. I get overly competitive too. But, this kid knows little to nothing about karts so... I'm willing to help him get a good grade on this , We may make him a fellow karter. As an added bonus, when I have a pencil and ruler in my hand I don't grab the bottle. Sober 4 months now.

---------- Post added at 11:42 PM ---------- Previous post was at 11:40 PM ----------


Cool thanks have you built anything yet?

No...
Only finished designing

---------- Post added at 01:20 PM ---------- Previous post was at 01:14 PM ----------

There is one more thing too guys.......
I'll also send the judging category of the contest