Table of Contents
Kart Project Proposal
Buy/build a kart, splitting costs, and sharing ownership to enable cheap racing at karting circuits. This project is still in the early financial feasibility-stage, and is open to any and all suggestions.
The Goals
- To have fun
- To improve driving skills
- To examine the possibility of competitive racing (HAH!)
The Kart
I'm assuming most of us don't know very much about different karts, but feel free to add to the information here. The plan is to use mostly used parts, and overhaul/repair them as necessary to achieve our goals without breaking the bank.
Body
We need a good solid base to build on, designed for adults, but doesn't necessarily have to be in beautiful condition. We can fix rust or scrapes easily enough, but it would be nice to find a body with smooth, working bearings (2 on the rear axle and two on the steering struts) as these are very important to speed, and can be expensive.
| Models that fit the KT100 engines | ||
|---|---|---|
| Yamaha 7YC |  | |
| Yamaha 7YA |  | Nice paint-job. |
| MERLIN |  | |
| PCR Jaguar |  | Have heard good things about the handling of this body, and is popular overseas apparently. The manufacturer is in Italy apparently. |
| PRD 100 |  | |
There are lots of steering control rods, bearings, stays and supports that attach to the body, and if we could find one that came with all these it would be ideal.
Engine
The heart of the beast. This will determine how fast our fat asses get hauled around the circuit. From what I've seen, in Japan and even overseas the Yamaha KT100 line of engines is pretty much the standard for karting. By mixing and matching carburetors, exhaust, gearing and ignition systems, the same engine can cover a wide range of motoring competitions. There are other options, but sticking with a commonly used model makes it easier to find parts, have work done on it if it is ever needed, etc.
There aren't many output numbers available for these engines because they vary so much depending on the other hardware being used.
| 100cc 2-stroke Air-cooled Models | |||||
| Model | Photo | Starter | Weight | Output | Notes |
|---|---|---|---|---|---|
| Yamaha KT100SP |  | Push-start | Newer, more powerful version of the SD. | ||
| Yamaha KT100SD |  | Push-start | 11kg | 15hp | One of the most popular and durable models. |
| Yamaha KT100SC |  | Recoil-start | Good practice engine for beginners. | ||
| Yamaha KT100J |  | Recoil-start | 10kg | 9hp | Smaller, less-powerful version of the SD. |
| CRG SW97 |  | Push-start | Mysterious imported model? | ||
| PRD RK100EC |  | Electric-start | 17hp | ||
Cost
Obviously there is no way to foresee all costs, but this should be a rough estimate of what to expect.
Initial Costs
We split these among the members, and have joint-ownership of the items.
| Item | Amount | Cost |
|---|---|---|
| Complete Kart | 80,000 | |
| Shipping | 7,000 | |
| Helmet | 10,000 | |
| Jacket | 10,000 | |
| Spark Plug | 500 | |
| Bearings | x4 | 7,000 |
| Bolts/Nuts | ? | 2,000 |
| Sandpaper/Paint | 2,000 | |
| Total | 111,507 | |
Each driver will also have to pay these.
| Per Person Costs | |
|---|---|
| Circuit License | 3,000 |
| Yearly Renewal Fee | 1,000 |
So split among 4 people you might be looking at around 30,000 yen.
Monthly Fees
Storage at the circuit is handled by a couple different contractors. I was told between 3,000 and 4,000 yen per month.
Cost per Day of Racing
These could either be split among the members, or maybe divided according to who uses the kart the most. These numbers assume a 4-hour run at the circuit (maximum of 7!), averaging about 30kph, getting 20km/l for 120km of driving for every trip to the circuit. (unrealistically high) I don't know much about how long these tires last, and I'm sure that it depends on your driving style. I'll calculate that we purchase brand new tires and use them until they're all gone, or 1,600km/tire for now. Of course for us used tires are probably just as good…
| Item | Unit Cost | Amount per trip | Cost |
|---|---|---|---|
| Track Rental | 6,000 | 6,000 | |
| Gasoline | 180 | 6.0L | 1,080 |
| 2-cycle Oil | 500 | .24L | 120 |
| Tires(new) | 5,000 | 1/3 tire | 1,500 |
| Sub-total | 8,700 | ||
| Insurance | 1,000 | 1+3 drivers | 3,000 |
| Total | 11,700 | ||
Again, split between four people this would come to about 3,000 yen.
Cost Comparison with Kart Rental
This comparison has to assume a lot of variables, but I have tried to keep them fairly moderate. In this calculation, 4 of us visit the track once a month and drive for 1 hour (each). Of course there are some differences, such as not being able to race against each-other, or having the track to yourself, but for comparative purposes I'm just focusing on the financial side of things.
1 Race per Month Comparison
| Monthly Cost per Driver | 1 Race per Month | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Asia Pacific Kart | 34,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 | 4,000 |
| Rental Kart | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 | 10,000 |
| Cumulative Cost | 1 Race per Month | |||||||||||
| Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Asia Pacific Kart | 34,000 | 38,000 | 42,000 | 46,000 | 50,000 | 54,000 | 58,000 | 62,000 | 66,000 | 70,000 | 74,000 | 78,000 |
| Rental Kart | 10,000 | 20,000 | 30,000 | 40,000 | 50,000 | 60,000 | 70,000 | 80,000 | 90,000 | 100,000 | 110,000 | 120,000 |
As you can see, 4 people investing in a kart, storing it at the circuit, and buying a circuit license (1 year) will save enough money each month to break even by the 4th month.
2 Races per Month Comparison
For reference, here are the same costs assuming 2 races a month (though that's probably pushing it for some people).
| Monthly Cost Per Driver | 2 Races per Month | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Asia Pacific Kart | 37,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 | 7,000 |
| Rental Kart | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 | 20,000 |
| Cumulative Cost | 2 Races per Month | |||||||||||
| Month | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 |
| Asia Pacific Kart | 37,000 | 44,000 | 51,000 | 58,000 | 65,000 | 72,000 | 79,000 | 86,000 | 93,000 | 100,000 | 107,000 | 114,000 |
| Rental Kart | 20,000 | 40,000 | 60,000 | 80,000 | 100,000 | 120,000 | 140,000 | 160,000 | 180,000 | 200,000 | 220,000 | 240,000 |
To put it simply, you've broken even by your 4th race if you have your own kart (shared between 4 people). This is only assuming we pay 6,000 yen to race all-day, but only actually race for 4 hours. We could race for up to 7 hours for the same cost if any of us were crazy enough to. ;) The hidden costs are in the kart though. There's always a chance the engine could detonate on the first lap.. but then again, it's more probable that it will last a good 30-40,000km. It's definitely an investment, but if we do this karting thing much at all I think it's a sound one.