Slow take off

[Bighomedog11]

Hey I am wondering is there anyway i can speed my take off speed up. I am using a Live Axle kart and when i take off it is like a slug.. It will barely go. I am wondering is there away i can make the take off better?

 

[modelengineer]

Change the gear ratio down, like 7:1 or 8:1 depending on tyre size. What's the current top speed?

 

[ramairgtz]

What motor are you running? Tire size? Current sprocket sizes?

 

[r97]

http://gokartguru.com/engineering_tool_kit.php

 

[jeremybentham]

Cheapie clutches from say Northern Tool and the like, engage at 1600 - 1750 rpm, give or take. Find a NORAM clutch that you can adjust what rpm it engages at. They can be had for roughly $35 used with driver. I got one a few weeks ago and it RULES. I can't begin to tell you how big of a difference it made. Mine engages at ~2400 rpm so my rpm are already up and I'm already in the power band of my cam when I take off.
Also, the bigger your axle sprocket, the faster you take off, but you'll have a lower top speed. I run a 5.4 - 6 gear ratio and git goin quick, and can still go 40 mph or so.

 

[Bluethunder3320]

what motor are you using?

 

[Bighomedog11]

The sprocket has 60 teeth and the clutch has 10 teeth.
And i am using a 6.5 motor

 

[redsox985]

That's a pretty standard set up. How much does this thing weigh? What size are your tires?

 

[Bighomedog11]

That's a pretty standard set up. How much does this thing weigh? What size are your tires?

Umm i am not sure on how much it weighs. But it is not light.

I have some big tires on the rear and front. Not super big but they are bigger then normal yard kart.

 

[ramairgtz]

Look on the tire is will say somewhere what size they are.

 

[Bighomedog11]

Look on the tire is will say somewhere what size they are.

Yeah i kno
Back tire is 16x8.0-7 And front tire is 145x70-6

 

[jeremybentham]

Smaller rear tires, or a larger rear sprocket and, assuming your clutch is functioning properly, your problem will likely be solved.

 

[Bighomedog11]

Smaller rear tires, or a larger rear sprocket and, assuming your clutch is functioning properly, your problem will likely be solved.

So i need a larger rear sprocket? I thought if i get a larger sprocket it will make my low end decrees even more?

 

[redsox985]

No, larger rear sprocket reduces the ratio to, say 7 or 8:1. Your top end will be lower, but take off will be better. And it will be easier on your clutch. To avoid ungodly sized sprockets, a jack shaft setup can be used.

 

[jeremybentham]

Larger sprocket decreases TOP end.
Take a look at this
http://www.gokartracing.org/Calculate.htm

Don't let the "top speed" fool you. Yeah, you can go 40mph, but with too high a gear ratio, it'll take you a mile to do it. My setup when plugged into the calc. shows 29.158. I take off fine and go like a raped ape. Yours shows 40.8. It's all about finding the balance between getting going quickly, and going as fast as you wish to go. You sacrifice one for the other. I pm'd you too.

 

[Bighomedog11]

Oh, I want to have better take of. So when i am in the dirt it will be able to go and not get stuck.
What is a good sprocket size i should get then? Yeah i know i will decrease top end. But that is fine. I rather have stronger take off and power. But i still want some top end.

Whats a good size sprocket for my tires and stuff?

I got the PM I will read what you sent me.

 

[redsox985]

Try a 72 tooth. Are you using #35 or #40 chain?

 

[Bighomedog11]

So if i get a 72t will i notice alot more low end power? And faster take off?

I am using a #35 chain (i think)

 

[jeremybentham]

I'd say you could use anywhere from 70 - 80 tooth with noticeable results.

 

[Bighomedog11]

Alright. I might try a 72t. but i want something that i will notice a difference in my low end take off.