Crt ?
 

To anyone that has a crt not the mini but the full size crt. I'm trying to use brian's calulator but i need to know the diff ratio for the FR & RR diffs . Thank's

IIRC it's 3.31:1

Bye:018:

Yeah, the stock crt uses 43/13 diffs.

Thank's guys. What size spur are people running in the CRT ?. I would like to use mike's CRT truggy mount .

Well, you could look at is this way:

Situation #1

Stock 3.31:1 diffs + stock steel 62 spur + 14-16 pinion= worn out pinions every other run.:035:

Situation #2

HB LSP r&p 4.3:1 diffs + kyosho plastic 46 spur + 14-16 pinion= happy pinions:018:

Hope this helps!

Bye:027:

Im definetly not gonna buy new diffs . The CRT im getting sunday is brand new & unused. What about the ofna 51t spur ?.

This is what i got using the ofna 51t spur & stock diffs.



post:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 51
Pinion Tooth Count: 12
Total Voltage: 14.8
Motor KV: 1853
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 4.25 : 1
Total Ratio: 14.05769 : 1
Tire Circumference (inches): 17.28 inches (438.88mm)
Total Motor Speed: 27424.4 RPM
Vehicle Speed: 31.92 MPH (51.28km/h)
Effective Speed Rate: 2.16mph/V (3.46kmh/V)
Effective KV Value: 1853

Not necessarily. The key to long-lasting pinion is a solid and consistent mesh. Both Mike and I (and maybe others) have run steel on steel with very good results. I've run my Hyper8 for about 10-12 packs' worth and the pinion still looks very good. The only downside to steel pinions is the cost compared to regular pinions.

Yes, I know that, but not everyone has got the money for hardened steel pinions and can achieve an absolutely perfect and consistent mesh.

@rchippie
- you would only need the ring and pinion gears, not complete diffs....

Bye:018:

*EDIT* Brian, actually when I had a dual HV-maxx e-maxx I ran a RRP 65t hardened steel spur with kyosho pinions and had no ill effects at all over many, many runs. But, when I put RRP pinions on (just to change ratio) the pinions lasted maybe 3 runs at most. Weird:confused:

here are the results with a 60 amp load using a 51t 12 gearing.
Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 51
Pinion Tooth Count: 12
Total Voltage: 14.8
Motor KV: 1853
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 0
Motor Current Draw: 60
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 4.25 : 1
Total Ratio: 14.05769 : 1
Tire Circumference (inches): 17.28 inches (438.88mm)
Total Motor Speed: 26401.54 RPM
Vehicle Speed: 30.73 MPH (49.36km/h)
Effective Speed Rate: 2.08mph/V (3.34kmh/V)
Effective KV Value: 1783.89

Were the pinion teeth shaped the same? Remember, some have different pressure angles, which can make a HUGE difference in pinion longevity.

Yup, shaped the same, standard 32p. Maybe the RRP pinions were aluminum and not steel? IIRC, I thought they were steel, I think traxxas ones are at least...

Bye:018:

After talking with mike & brian this is what im going with. The motor is a 9XL

post:

Differential Ratio: 3.3076923076923075
Transmission Ratio: 1
Other Ratio: 1
Spur Tooth Count: 62
Pinion Tooth Count: 16
Total Voltage: 14.8
Motor KV: 1853
Tire Diameter (inches): 5.5
Tire Ballooning (inches): 0
Motor Current Draw: 60
Motor coil Ω: 0.0092
Spur/Pinion Ratio: 3.88 : 1
Total Ratio: 12.81731 : 1
Tire Circumference (inches): 17.28 inches (438.88mm)
Total Motor Speed: 26401.54 RPM
Vehicle Speed: 33.7 MPH (54.14km/h)
Effective Speed Rate: 2.28mph/V (3.66kmh/V)
Effective KV Value: 1783.89

Actually, I told hippie he needs to send me his truck, but he didn't like that idea. :)

Dont be made :005: . Brian what do you think of my last post about yor calculator ?.

Sounds good to me - nothing looks bad. I just want to see it finished; that's the true test. :)

A little off-topic, but have you figured out your buggy delimna, or are you going to scrap it to do the truggy?