These are optional Light Blue Kyosho Inferno Big Bore shock springs, this is the Medium Short length and are used on the front or the rear of the MP9s.These are optional front or rear springs for the Inferno MP9 TKi2 and 3.
Here is a spring rate chart of the available springs for the Kyosho Inferno Big Bores:
These are some guidelines for choosing different spring rates for your setup on your Kyosho Inferno. Remember that every change you make to your setup will effect something else. It is a good idea to experiment by changing settings to get a feel for how changes effect your car with your driving style. Further reading on the subject of chassis set will also help. Try and hang with experienced drivers at the tracks you race at will also help immensely!
You can use different spring rate shock springs to alter your setup. Basically these are the direct effects of changing springs:
Effects of Softer Springs:
Gives you more chassis roll
More traction overall
Handles better on bumpy tracks
Shock Bottom out more easily from big jumps
Effects of Harder Spring:
Less Chassis roll;
Less overall traction
More sharp and responsive
Handles better on smooth tracks
Reduces bottoming from large jumps
Text Version of the above Chart:
Short Length Shocks (S) 70mm
Medium Length Shocks (M) 84mm
Long Length Shocks (L) 95-97mm
Green IF350-814 - 8 turns 1.4 wire
Orange IF-350-7514 - 7.5 turns 1.4 wire
Light Blue IF350-714 - 7 turns 1.4 wire
White IF350-1016 - 10 turns 1.6 wire
Gray IF350-6514 - 6 turns 1.4 wire
Purple IF350-916 - 9 turns 1.6 wire
Light Green IF350-816 - 8 turns 1.6 wire
Blue IF350-716 - 7 turns 1.6 wire
Yellow IS106-9514 - 9.5 turns 1.4 wire
Green IS106-914 - 9 turns 1.4 wire
Orange IS106-8514 - 8.5 turns 1.4 wire
Light Blue IS106-814 - 8 turns 1.4 wire
White IS106-1116 - 11 turns 1.6 wire
Purple IS106-1016 - 10 turns 1.6 wire
Light Green IS106-916 - 9 turns 1.6 wire
Blue IS106-816 - 8 turns 1.6 wire
Green IF348-1114 - 11 turns 1.4 wire
Light Blue IF348-1014 - 10 turns 1.4 wire
White IF348-1316 - 13 turns 1.6 wire
Purple IF348-1216 - 12 turns 1.6 wire
Light Green IF348-1116 - 11 turns 1.6 wire
Blue IF349-1016 - 10 turns 1.6 wire
Red IF348-916 - 9 turns 1.6 wire
Explanation for the spring rates in the charts above:
The part number of the Kyosho spring has the wire thickness and number of turns included in it.
IF350-716 equates to:
7 turns of 1.6 thick wire.
This can be extrapolated to all the springs and you will see the pattern evolve for the spring rates.
Thicker wire = stiffer spring
More turns in wire = softer spring
Just think of this like a spring is a piece of wire. If you straightened out the wire and held it on one end, the longer it is, the easier it would bend by pushing on it from the opposite end. The same would hold true for a thinner piece of wire, it would be easier to bend as well. This is how springs are actually working. The longer the wire the easier it is to bend and therefore the softer spring rate it has. An advantage of lower turns and thinner wire is you can create a spring with lighter weight vs. a spring with thicker wire and more turns. Keep this in mind when choosing springs to run as well.
I hope this explanation helps rid some confusion about how the above charts work.