Well I have to say production
gear diff is sweet and they put a lot of work into making not only the gears light, but the diff case also. I can say that with minimal prep it's a nicer piece than the tamiya gen 2 diff(tamiya diff needs break in to be butter smooth). The Oring / gasket combination is nice. The outdrive oring material is the same as the NT1 so it shouldn't leak and should be good for many runs before there is a need to change the oil. Be careful when using putty in the front position, if you do it might be a good idea to have spare gear sets.
Since I don't know of any mfg's that make anything higher than 1300cst in increments of 100cst here is some math help for mixing your own solutions out of say 1000 and 2000cst.
Calculating the viscosity of a blended liquid consisting of two or more liquids having different viscosities is a three step procedure. The first step involves calculation of the Viscosity Blending Index (VBI) of each component of the blend using the following equation (known as a Refutas equation):
(1) VBI = 14.534 × ln[ln(v + 0.8)] + 10.975
where v is the viscosity in centistokes and ln is the natural logarithm (Loge).
The second step involves using this blending equation:
(2) VBI-blend = [wA × VBIA] + [wB × VBIB] + ... + [wX × VBIX]
where w is the weight fraction (i.e., % ÷ 100) of each component of the blend. In using the above blending equation, it is necessary that all viscosities are determined at the same temperature, for example, 22 °C.
The third and final step is to determine the viscosity of the blend by using the invert of equation (1):
(3) v = (ee(VBI - 10.975) ÷ 14.534) − 0.8
where VBI is the Viscosity Blending Index of the blend and e is the transcendental number 2.71828, also known as Euler's number.
Note the weight fraction can be found by weighing the empty diff case and filling appropriately (tare the diff case while loaded with the planetary gears ~7.9grams) keep in mind that 100% solution would weigh approximately 1.3 grams. If you don't feel like doing algebra you can use the scale method for mixing a consistent solution from build to build. (Ex: Adding .65 grams of 1000cst and .65 gr of 2000cst to make your builds consistent while mixing with non algebraic methods)
Can't wait for the North West Indoor Championships to start