Scale 1/8 buggy

[BrianG]

You're welcome paul. There was effort made to make my version as easy to use as possible. :)

As to the battery voltage rating: I do understand that the battery voltage will drop under heavy load. But that load happens under heavy acceleration (anytime the motor is forced to change speed in a short amount of time). Once you get near the top speed, the rate of acceleration will be less, therefore less load and therefore less voltage loss, so you get closer to the nominal voltage. What I do is make a worst case and best case scenario. I figure everything using low battery voltage (~1v/cell) and then again at a more ideal battery voltage (~1.3v/cell). The real figure is usually somewhere in the middle.

Generally, you match your motor and battery voltage so that you don't exceed ~35k rpm. If using a low KV motor, you can use higher voltage. If you are using a faster motor, you use less voltage. Then, you try to gear approriately for the speed you want ... within reason. Usually, you get less losses using higher voltage and a low kv motor since current will be less. But there are usually limits to how many batteries you can physically fit, not to mention the capacility of the ESC.

If you are going to use this buggy for racing on an offroad track, then 35mph seems to be the common desired top speed. If on-road racing, you can go faster more easily since there is more traction control and the terrain is easier to accelerate on.

[nativepaul]

well as im trying to do this on a shoestring I have the motor and cells allready so the only variable is the gears, I hope thats enough. With a 44t spur and 16t pinion, I get 33-40mph from 1-1.3v on the lightnings 4.58" tyres. That seems good forf the off road set up.

The rpm is well under 35k tho at 25-29k, will this make me more likely to smoke anything?

What about for on road? I looked at on road wheels and tyres, they use the same wheel but are lower profile so they are smaller diameter, thus if i just fit road tyres to run in the street it will be slower than off road, so I will need to swap pinions with the wheels.

Can anyone recomend a rubber road tyre that is decently grippy but very long lasting to suit my budget over time, and tell me the diameter so I can speed calc it.

If I should gear for 35mph off road, how fast should I go on road, and still be able to run hard for the batterys duration, without smokeing anything?

Why wont a 46t fit? The stock should be a 50t, dunno why it wouldnt work.

[skeeler]

nativepaul,

You asked about rally bodies. Kyosho makes a short-travel, rally-bodied version of the Inferno 7.5 called the Inferno GT. It comes with Subaru Imprezza WRC, BMW M3, Nissan 350Z, and Aston Martin DBR-9 bodies, and the bodies are available separately. Here's the Subaru model on the Kyosho site:

http://kyoshoamerica.com/carsandtruc...ars/31811B.asp

There's a whole forum for this car here:

http://infernogt.proboards102.com/

[nativepaul]

I read that the hole in the chassis needed enlarging, if stock is 50t of the same pitch, the diameter must fit, so I'm guessing the plastic one has wider teeth, but I have neither buggy nor spur yet so I can't say for sure.

As it turns out the 44t is a better match for my motor anyway, or maybe slightly too big for an on-road set up, dependeing on speeds and tyre size.

[nativepaul]

well I took the plunge and bought a lightning 2 pro earlier today, i guess by the weekend ill have it and get the measurements for the diff mount.
Does anyone know if the lightning 2 pro diff mounts are the same as the lightning stadium ones?