Clutches
If you own a nitro car then a clutch is an essential part of your transmission and plays a vital part in getting the power to the wheels. As with a full sized vehicle, any wheel spin will be a waste of power and will be wasting precious rubber from your tires.
Although you don't really have much control over the clutch, you can control clutch engagement. That is you can control at what point on the engines rev curve the clutch engages.
To see the advantages of this you have to understand that your RC car engine has different amounts of torque throughout its rev range. If your engine is spinning fast then the torque is going to be at its maximum and a wheel spin is inevitable. If the engine is spinning slower then a wheel spin is less likely and you will pull away faster and in a more controlled manner.
Given the information above it should be no surprise that on a slippery surface such as dust or sand dunes you should set your clutch engagement to a low point in the rev range in an attempt to avoid too much wheel spin. If the surface is far grippier then you could move your clutch engagement higher in the rev range.
Your engagement can be adjusted by using different shoes and springs. Check your manufacturer for which clutch shoes are suitable for which situation.
Differentials
The differentials perform a very important task on the car. Without the differentials all the wheels would turn at the same speed all of time. This might sound ideal, and it is if you are going in a straight line. When a car turns a corner however the inside wheels will naturally try to rotate slower than the outside ones causing a conflict and unstable handling.
The differential will allow the slower wheel to slow down and the outside wheel to turn faster. The amount of differential action is controllable by altering the viscosity of the silicone fluid in the differential. A thicker silicone fluid will mean less differential action.
On modern cars there are usually three differentials, One at the front axle, one at the back axle and one in the centre. By adjusting the amount of differential action you can drastically affect the handling and performance.
The centre differential affects the front/rear difference and can help you prevent your car from pulling a wheelie. Thinner fluid in this differential will decrease over-steer and improve performance on bumpy terrain. Thicker fluid will give better acceleration and increased drive out of corners.
The front differential affects overall steering. Thicker oil will make the car feel more stable but less responsive, thinner fluid will increase the responsiveness of the steering.
The rear differential controls the traction in the corners. Thicker fluid will reduce inside wheel spin and decreases the rear grip, giving a better chance of oversteer. Thinner fluid will give more traction in the corners.
Average 1:8 Buggy diff oil set up 3-5000 weight oil in front diffs 5-10,000 weight oil in centre diffs 1-2000 weight oil in rear diffs
Shock absorber springs Shock absorbers are essential for any buggy to perform over rugged land. They help keep the buggy from bouncing all over the place out of control. The springs are a vital part of the shock absorber.
Generally speaking the smoother the surface the harder the spring required. If the track is bumpy go for a softer spring.
Hard Springs
Less chassis roll, good for smooth surfaces
Soft Springs
More traction & smoother ride on bumpy surfaces
