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Great choices, but I'm thinking your battery might be bad. That thing should be blistering with that motor and esc. Something seems off.

6 gear or stealth? Spur teeth? Pinion teeth?

THEYTOOKMYTHUMB wrote:Great choices, but I'm thinking your battery might be bad. That thing should be blistering with that motor and esc. Something seems off.

X2. Even a 6gear geared thru the roof it should be alot quicker. I thought you were talkin an old school brushed setup with that speed. If you have access to even a mild cheap lipo try that and compare...or even a different battery.
Todd

Its a 6 gear with bearings. The spur and pinion...ummm, not sure but its not stock. I'd have to count the teeth. Maybe I'll take a pic and post it

I am sure its faster than the speed posted (it has to be) but I'll have to re-measure a 100 ft section to be more accurate I think. I also figured out what I was doing wrong with the ipad app so let's try it again today

Oh and I forgot to mention that the car was sliding sideways a lot through the speedtrap because I did a standing start. I should probably do a rolling start just so I can hit top speed between the lines and make it more accurate.

you need to be at top speed before you ever hit the first line. no wonder it shows you're only going 20.

I use my GPS, worked well so far. If you don't have a GPS and don't mind spending a little cash, there's the Venom Speed Meter VEN-0615 for around 40 bucks.
http://www.google.com/products/catalog?hl=en&rls=com.microsoft:en-us&q=venom+rc+speedometer&bav=on.2,or.r_gc.r_pw.&biw=1260&bih=563&wrapid=tlif130857875434310&um=1&ie=UTF-8&tbm=shop&cid=11763335122013509331&sa=X&ei=PFX_Tcn9Hcq10AGcmISsBw&ved=0CEAQ8wIwAQ#

scr8p wrote:you need to be at top speed before you ever hit the first line. no wonder it shows you're only going 20.

Yes, I thought something was fishy Seriously though, I did a rolling start today at lunch time (just now) and got some dramatically different results:

59.87 mph
60.12 mph

Those still seem a bit optimistic as I don't *think* its going quite that fast (could be wrong though). I only used the iPad application today but it was hard to hold it upright while driving the car at the same time

At any rate, when the kids get home from school this afternoon I will get them to help me out and I will do it again both ways - a few runs with the iPad radar gun app and a few runs with a stop watch on a 100ft section, rolling start.

Should be interesting to see how it turns out!

Assuming a few things - http://dhrc.rchomepage.com/RolloutCalc.htm:

54 tooth spur (but if not stock this would be wrong)
14 tooth pinion (???)
1.83 internal ratio (6-gear - this right?)

2.6 inch outside rear wheel diameter

this is for 8.4V battery 4900kv motor

gives you 40 mph

Okay just did a quick count (so might not be 100% accurate) but I have what appears to be a 70 tooth spur and a 24 tooth pinion. Does that even make sense? Too many teeth on the spur to count so I counted one group by one hole then multiplied out by the number of holes

Yes, stock 6 gear tranny with bearings.

floodx wrote:Assuming a few things - http://dhrc.rchomepage.com/RolloutCalc.htm:

54 tooth spur (but if not stock this would be wrong)
14 tooth pinion (???)
1.83 internal ratio (6-gear - this right?)

2.6 inch outside rear wheel diameter

this is for 8.4V battery 4900kv motor

gives you 40 mph

If I change the inputs as follows:

70 tooth spur
24 tooth pinion
1.83 internal gear ratio
2.75 inch outside rear wheel diameter (just measured)

That gives me 60.9 mph. Wow, so maybe the iPad measurements weren't that far off after all.

Hunh....cool.

I pulled 38.8MPH with my RC-10 with a stealth and a 10.5 turn BL. I thought that was fast, but 60MPH!! Cool!

According to a similar calculator as the previous link, which used gear ratios, tire diameter, motor pinion & RPM & kV rating and battery details, I was in the neighborhood of 40 mph with a Turbo Optima/14T brushed motor/8.4V NiMH battery/9T pinion gear. To be honest, it's too fast at that speed, unless one is only interested in straight-line speed-runs.

A track has to be pretty big to make full use of 40+ mph speeds in a 1/10-scale car, I think. Just my 2 cents.

I recommend that you talk to your local cop. They have been known to verify speeds, help test radar detectors, etc for those who ask.

Dirtdiver wrote:I recommend that you talk to your local cop. They have been known to verify speeds, help test radar detectors, etc for those who ask.

What seriously?? lol I dunno...but I will be trying it out again in a few mins to see what I come up with and I will report back shortly