Thanks to everyone who contributed in this thread. I recently picked up a pair of these and got back into RC a bit after a few years off (about 3 decades worth).

My kid and I have had loads of fun with them as stock. And I started to read up on the new (to me) electronics and dabble in some telemetry as well for fun. So I recently thought I'd walk through a few different setups and provide some data.

I don't have much to add on track/handling performance. Were mostly just street or curb bashing and having fun. But I did move to 16bl30 ESC's on both to mess with programming. And then it was all downhill from there.... motors, esc, radio, gps... lol.

So here's a quick summary of some testing I just completed. I figured I was about due to redux the diffs and I have the new fancy shock bits on the way from associated, so I figured I'd throw some motor and esc at one to see how far things would get.

Reflex Speedrun Test (part 1)

Top speed measured with SKYRC GSM020 as well as Spektrum SPMA95870. They were typically within 1mph of each other.

Run 1 : Stock 14b + Quicrun 16BL30 ESC + Trinity 2S 1600mAh 30C pack + Stock Reedy 4500k + 16t

Wanted to get a baseline. Note, the road I'm testing on has a grade. So it's a slightly downhill number. I spreadsheet-ed an estimated speed for each run based on gearing (2.46 trans, 3.36 spur) wheel diameter, and kv to predict an estimate (including some ballooning as well as some ESC inefficiency).

Top Speed (estimated) - 29.7 mph
Top Speed (measured) - 29 mph

Run 2: See above, replace stock tires (2.75" dia) with LC Rally wheels/tires (2.5" dia).

I'm guessing the stock tires are going to be not good for speed runs. Too much possible ballooning. Ballooning is bad... an unwanted spike on the drive-train and current. I figured I'd get some baseline tests in with the stock tires first but end up on foam or road tires and wanted to get baseline with these LC's as they seem to hold up well.

Top Speed (estimated) - 27.0 mph
Top Speed (measured) - 27 mph

Run 3 : Back to stock tires. Now I swapped in a Venom 3s pack 1300mA 20C. I figured 20C was enough when I bought it, but then I started doing some math. I'm guessing it (and maybe even the 16BL30) will current limit, but we'll see.

Top Speed (estimated) - 44.6 mph
Top Speed (measured) - 43 mph

Now we're starting to move!

Run 4 : Ok so when I bought the Quicrun I also saw that some folks had the Quickrun 2435 motor. I picked one up to try out. It's same 4500kv but it's 2 pole. My understanding is that 2 pole will have slightly higher current (and heat) to high slightly higher RPM. Same KV, but KV is with no load. What matters is how the gearing and load at RPM factor. So I wanted to see. So this "run 4" is with 2s and the Quicrun motor (it should compare directly to "run 1"

Top Speed (estimated) - 29.7 mph
Top Speed (measured) - 31 mph

Interesting. So maybe the 2-pole does indeed get to higher RPM... at least on 2S. Lets see on 3s next...

Run 5 : Same setup as above, but with the Venom 3s pack.

Top Speed (estimated) - 44.6 mph
Top Speed (measured) - 41 mph

In this case, the 4 pole was slightly faster. I suspect it may be because I'm now close to the current limit? So let's check that for the next test.

Run 6 : Same setup as "run 5" except swapped in a Quicrun 10BL60 ESC and MaxAmp 100C 3s pack. Note, i didn't weigh things, but the maxamp pack is a lot heavier than the venom 3s.

So this should increase current to 60 amps (if any of these specs are worth a dime).

Top Speed (estimated) - 44.6 mph
Top Speed (measured) - 44 mph

Ok a measurable difference. So maybe these things really are drawing some juice. Note that at 40+ mph those stock tires are ballooning a bit. I estimate diameter increases ~20% at speed... so 2.75 becomes over 3". That's quite the additional gearing. Not ideal.

Run 7 : At this point I'm wondering what all that extra juice can do. And it's where I made my first mistake. At this point I should have ditched the stock wheels tires and dropped down to the LC rally set or some road foams.

So I swapped in a TenShock 2838 that I had run on 2s and even 3s before with the older ESC. And I had a run or two in with it on the 2.5" road tires and it's scooting. So I expected this to be a bit nuts or break. Usually it's both, and it was. This version is a 6850kV which is like 6.5T (i'm old) and it hauls on 2S. It's way too much for 3S, but this was just a road run I needed to rebuild the diff anyway...

Top Speed (estimated) - 69 mph
Top Speed (measured) - 54 mph (diff blew during run).

Note - the 69 mph estimate is likely unobtainable. That would be like ~80k RPM. I don't know what these $29.99 motors can do, but I'm pretty sure will turn into light light bulbs at 80k rpm. I'm guessing any significant gain will need to be in gearing with tires that can handle speed.

I tried to slow roll it but with the final punch it was wheel standing. So much ballooning the tires looked like saucers. I'm not sure when the diff blew, but I appreciated my 2nd favorite discovery of RC these days... the gyro steering (Spektrum AVC) which kept it straight despite the craziness.

So... that ends part 1. This stripped the spur gear, the inside diff bearing decoupled, and the diff out drive cap was toast. So I'm waiting on diff caps and I'll probably order some foams. Sitting in the box next to the TenShock 2838 are the US Racestar 2845's (5000kv and 5900kv) that I'll try next. I also have the Hot Racing 18T... but that's as big as I've been able to find in mod 0.5.

Hope the data is useful. I'll update with part 2 once rebuilt.