Motor/gearing chart, please help me...

[akemag]

Ok, so i´m stupid...

But you guys arent!

Thing is that i bought a skyline speed tuned gear set for my hummer, and i´m trying to understand the gearing/motor chart.

I just dont get the chart that shows which motor to use with a certain pinion/spur gear.

If you look at the manual 58157 and page 5, theres a chart showing different combinations.

The part i dont get is the motor choice at the bottom.

With a 69t spur and a 21t pinion you should use a TRF tuned motor, a pretty hot one i guess.

With a 69t spur and a 23t pinion (faster setup?) you should have a acto power(less power motor?).

With a 68t spur and a 24t (even faster setup?)pinion you should have a sporttuned (much less power than acto power?)

I dont get it! The biggest pinion and the smallest spur must be for the fastest setup, gets to use a sporttuned.

Shouldnt that setup need a real hot motor to drag that gear ratio.

Am i getting all this wrong?

[Tipsy]

As with all modified motors, the higher spec/RPM it has the lower the gearing you need to reduce the motor overheating, as higher gearing puts more load on it as it spins up. Modified motors need to spin up to their best RPM quickly.

[akemag]

So to use a sporttuned with a 68t spur and a 24t pinion as the chart says should be good. But does it have the power needed?

[Tipsy]

Yes, most of the low end motors from Tamiya have plenty of torque. Also they dont draw anywhere near as much current when running. so would stay cooler. You would find that with a lower ratio on the cheaper motors, there would be not much speed at all

[akemag]

Ok!

Hope it will be a bit faster than the standars setup in any case.

I´m getting a Superstock RZ soon with 500g-cm of torque, maybee that one will do better.

[Tipsy]

The Superstock motors are brilliant in my opinion. I have a few of them. Have totally transformed a Baja Champ runner

[akemag]

Good to hear!

I was planning to upgrade my Hummer, 850BTCC and perhaps my Monster beetle.

Do you know if the RZ is rebuildable?

[Tipsy]

Yep. RZ & TZ Rebuildable. They use laydown type brushes

[akemag]

Thanks alot Tipsy!

[Forum Fodder]

RZ used laydown, TZ uses standup brushes

[akemag]

Whats the difference? And looking at the specs they are virtually identical.

[Forum Fodder]

Laydown gives better rpm, standup gives better torque. Other than that the motors are indentical. For use other than for racing it makes very little difference at all.

[akemag]

Thanks for the explanation.

What do you think of the gearing i´ve planned on my Hummer. 24T pinion and 68T spur. Would it work good with the RZ and the Hummers rather large tires?