13.5 'blinky' gearing

[a.wojtecki]

Hi there,

I'm looking for some advice on gearing a GM 13.5, with a Tekin RS Pro, for a relatively small indoor carpet track (1/10 touring). At the moment my fdr is 8.0 with boost set at 40-45 and turbo at 10. The club rules have changed so I've now got to turn off all the timing and go blinky :thumbdown: - so what would be a good starting point to change my fdr to?

Thanks in advance

[dale]

Probably start around 6.5 for a small indoor track, and gear up from there if you need more speed. No point starting too high and frying the motor.

[sosidge]

Our club runs 13.5 blinky indoors on a pretty small track (18m x 8m) and I'm at 5.8:1 with a Speed Passion v3.

You might :thumbdown: about blinky now but I suspect that when you actually run it you will wonder why you wasted so much time with boosted. The throttle feel is so much better and on a small track you just cannot use the power of boosted. Going blinky has been a hugely positive move for our club.

[a.wojtecki]

Thanks for your help - I'll start off around 6.0 and work from there. I think that that was around where I was geared when I ran a 13.5 X11 and Sphere esc.
I'll see how blinky goes - but I'm certain that it'll be more than a quarter of a second a lap slower (the difference between my best and average lap running boosted) and hence will inevitably be slower overall.

[Craig W]

Hi there,

I'm looking for some advice on gearing a GM 13.5, with a Tekin RS Pro, for a relatively small indoor carpet track (1/10 touring). At the moment my fdr is 8.0 with boost set at 40-45 and turbo at 10. The club rules have changed so I've now got to turn off all the timing and go blinky :thumbdown: - so what would be a good starting point to change my fdr to?

Thanks in advance
try 4.5 to 5.4

[a.wojtecki]

Right - time to report back after racing today. I ended up running a ratio of 5.47 (as a 41 tooth pinion was the largest that would fit with the 115 tooth spur in the car) and the motor came off after five minutes at about 41 degrees C. I've ordered a 104 tooth spur so will be able to achieve much lower ratios - I expect I could end up around 5.0. I've found that my current GM motor (coupled with the Tekin esc) is much more capable than the X11 LRP that I ran a few years back - the acceleration would really suffer when I tried gearing that motor up but the GM has so much torque that each time I went for a larger pinion the top speed went up and there didn't seem to be any reduction in acceleration at all.

As for my thoughts on blinky - the main difference I noticed was a slightly lower top speed and noticeably less power at the top end. However the difference was not that great as the track consists mostly of corners - so the key aspect of motor performance is acceleration from low to mid speed. In that regard it wasn't that much easier to perfect the racing lines. The regulation is actually 17.5 blinky (I'm still on 13.5 as I haven't yet invested in a 17.5) - so I suspect that that could have a greater impact on making the car easier to drive.