Thinking about a speed run car

[BrianG]

Originally Posted by Metallover

The diameter of the spur gear on my tc3 is about 40mm. what's the diameter of your 44t spur?

44T 32p spur is 36.51mm diameter.

http://scriptasylum.com/rc_speed/_gear_calc.html

[snellemin]

Doh, I just edited mine.

[Metallover]

Originally Posted by snellemin

Dunno man. Dont have the car here with me. Figure that 44T 32p is equal to about 66T 48P. BrainG has the gear diameter calculator. 44T is equal to 36.5mm.

Awesome. Do you know off the top of your head what pinion you are running?

[snellemin]

I use pinions from 9-12T count. With bigger pinions I use sensored/hybrid mode.

[Metallover]

I'm thinking I could use what I have - My medusa 36-60-2000. yeah baby.

Gearing. I found if the spur/pinion are the same size, I should get around 88mph. I think 32p 44t pinion/spur should work; problem is finding the gears.

How can I make an adapter to run a spur for my pinion?

Differential Ratio: 2.5
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 35
Pinion Tooth Count: 35
Total Voltage: 14.8
Motor KV: 2000
Tire Diameter (inches): 2.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 1 : 1
Total Ratio: 2.5 : 1
Tire Circumference (inches): 7.85 inches (199.49 mm)
Total Motor Speed: 29600 RPM
Vehicle Speed: 88.06 mph (141.45 km/h)
Effective KV Value: 2000
KT constant: 0.68 oz-in/A

[snellemin]

The smallest 48p spur that I have seen is 46T, but it's doesn't have those diffballs holes.

[BL_RV0]

If you mesh the gears right you will not strip the 48p.

[snellemin]

I don't strip gears. But I hate swapping in new spurs when little rocks get in between the mesh of 48P gearing and locking up the motor.

[Metallover]

Originally Posted by BL_RV0

If you mesh the gears right you will not strip the 48p.

I'm not worried about gear mesh, but more my shaft size. I've got a 5mm shaft and 32p pinions are easer to find for a 5mm shaft; or can you find two equal tooth count 48p gears, the pinion with a 5mm shaft, the spur fitting in the tc3, and the two shafts about 35mm apart?

here are two cheap gyro's (i have the second one in my rustler)
http://cgi.ebay.com/Esky-Head-Lock-H...ayphotohosting
http://cgi.ebay.com/EK2-0704-Gyro-Fo...3%3A1|294%3A50

[Metallover]

Drove the car for a couple minutes with a 8-cell nimh pack. Don't have a charger for that pack so once it's gone its gone... It drove pretty good and it was pretty fun even at not so quick speeds. Once I split my 4s zippy I'll have a copule 2s packs I'll probably run in a parallel so I can still run them in a series later.

Temps were ~110-120 both on the motor and esc; battery was cold. I think the front diff is stripped or loose; I'll take it apart probably tomorrow or later tonight. I'll clean off my work bench first.

[speedracer1129]

Originally Posted by Metallover

I want to car to be a low set as possible, have cooling holes, and have a boat tail if possible.


That guy running the tc4 with the 7700 completely stock,,, will I need to upgrade the tc3 to make it hold up to the power the tc4 does?

The TC3 and TC4 have the same drivetrain. It will hold the power......

http://www.youtube.com/watch?v=GzRAOMMd8a4

[speedracer1129]

Originally Posted by Metallover

I have a flightpower 30c 3300mah 3s lipo, but I'm not sure that'll have the punch. Maybe I can use that and the frickin castle normally-useless 9000kv motor?

This battery fits fine. The above car in the vid is running the same batt but in 4S.

[Metallover]

Are you the shooter of that video? That Channel? I've watched a bunch of those speed run vids... Any tips or tricks?

[speedracer1129]

Originally Posted by Metallover

Are you the shooter of that video? That Channel? I've watched a bunch of those speed run vids... Any tips or tricks?

Negative. I was the one radaring it. I was actually the one who came up with the setup 1 year and a half ago working with some help from CC. We have been running high spped cars for several years but I wanted to build a 100+ car with 100% off the shelf parts. Nothing custom!! The TC4 was the ticket!!

As far as tips, all I can say is that the power is available. The key is the setup of the car. Suspension and body choice are very important!!