Optima Mid (runner)
I've posted some pics of this one before, when asking for why made the body shell. This is my main Optima Mid runner, just to relive the fond moments I had when driving the white Optima Mid from the 3rd posting. I came with shell painted as boxart, but with the windows painted white as well. Then I got this "graffity-style" RaceCraft shell, and "married" it to this Optima Mid. Also came with stock LeMans 240ST motor fitted, but even on 2S LiPo, it wasn't as zippy as I remembered my first Mid, and that was running NiCads back then. Mind you, those were top NiCads, Sanyo SCRC 1900, matched cells, probably better then average quality NiMh of today.
Anyway, I looked at the brushed motors I had lying around. I didn't want a too strong motor, like an 11 turns high rpm for instance, as this might seriously reduce lifespan of the gears, and may also need additional cooling, as the secluded motor position of the Mid doesn't allow for much airflow over the motor. My eyes fell on a GM Racing Purple Beast 15 turns. It seemed to run a fair bit faster than the LeMans 240ST, and has good airflow through the car. I dropped a tooth on the pinion, from 20T to 19T, and gave it a go. Now the car was more like it. More wheelspin if accelerating hard, and better top end. Previously it clocked in at about 37 km/h at most, now it was almost 44 km/h top speed.
For a better comparison, check the vids listed here below:
http://vimeo.com/110719347 (stock motor)
http://vimeo.com/110715841 (GM motor)
(Reserved for some more cars)