Motors and Gears

[Bane]

First, I am a noob to the 1/32nd world. From what I have read about motors (rpm's) the higher the rpm the better top end speed, but you will sacrifice quick acceleration through the turns. The track I race on is a commercial track (carrera) with about a 20-25' straight, a few turns and then onto another straight for appox 15'. I am running either slot.its or NSR's with magnets, 20k shark motors with silicone tires. I wanted to try and pump up the performance. Can I go to a 30k motor and change the gear ratio in order to gain some in the straight as well as the corning/accel? Any recommendations - pinion 12 tooth with a 34 tooth gear? Is there a simple rule for every pinion tooth dropped how many you should increase with the gear? Thanks guys!

[chappy]

Bane, from what I understand, a drop of one tooth on the pinion is the same as an increas of 3 teeth on the spur. And an increase of 1 tooth is a decrease of 3 teeth on the spur. I may be out a bit on this but I think thats how, it works.
However if you are going from a 20 k motor to a 30 k motor, I would drive it before you change anything else.
Keep in mind that in this hobby as with most motor sports, you can have too much motor.
As a noob, you may not be familiar with rollout, so very quickly if using a 12 tooth pinion and 34 tooth spur, see in inches or mm how far your car moves for one comlete revolution of the motor.
Now if that motor is a 20 k, your gear ratio will tell, you how far it is capable, of travelling at max rpm.
Easy math now to figure how far it would travel at 30 k max rpm .
There are a lot of things that come into play with gears, such as ratio, but also gear diameter makes a difference to.
Just have some fun where you are and learn as you go along. Some folk have spent a lot of money on buying different motors and gears just to find it didnt give them the results they hoped for.
The guys at your club will be a good resource for you, so see what they are doing, most are willing to help a newcomer.
Regards
Bob

[RichD]

There is a limit to what you can do by changing gears, if you gear for more top speed, especially with a car that has a lot of magnetic downforce, the motor may overheat and the car will slow down. You may need a motor with more power. A motor with a higher RPM rating may not actually have more powe because the motor's torque rating is a factor as well. Power is rated in watts (W) and that can be calculated if you know both the RPM and torque ratings for a motor. Not all sellers publish torque ratings for their motors, but a lot of information based on actual test results can be found here: http://slotcarnews.blogspot.com/2007/02 ... -list.html
You should be aware that there can be some variation in performance for different examples of the same motor.

[Bane]

Few other things. Currently using inline motors.

Would I be better off switching to a sidewinder or angled motor?

With the new NSR's I can change out the frame from a soft to a hard as well as the guide. With a track that has some elevation changes and tight turns any recommendations on hard or soft? Has anyone used the spring suspensions, worth the change over?

[Bane]

Thanks guys! Part of the fun is tinkering with that stuff;). I am not really into competitive racing, but I enjoy seeing just how far I can go with a car. HO's were a lot easier in my opinion lol.

Rich, I did notice on some motors they had the grams of force indicated. I just bought an NSR audi R18 which has a 21,400 evo king with 322gr while most of my slot.its with a 20k motor are at 168gr.

[waaytoomuchintothis]

Yeah, but these guys are a lot more fun that HO when you get into scale racing. The commercial tracks and superzoomy, can't see it as it goes by cars offer one kind of thrills, but scale cars doing the best they can do by your own hand in the building is Valhalla for the tinkerer, by comparison. Have fun!

[dr fabio]

If you are running with traction magnets just find the motor with the biggest torque. The king 322gcm is a good choice. Start with a gear ratio around 3:1 (27/9). Want more top end speed try 25/9, want more acceleration try 29/9. Cant drive flat out through the corners add more traction magnets near the rear axle line. Run out of magnet pockets, just glue them in place.

[Bane]

Thanks fabio and everyone else!

Any preference for a sidewinder, angle or inline motor?

[dr fabio]

For non mag racing Id probably go sidewinder. For mag racing where youre not allowed to use additional magnets but must rely on the mag effect of the motor, long can angle winders are the go. Personally Id say inlines would be the go with traction magnets but thats a guess as I only race non mag on wood. Hopefully someone that races with mags will be able to confirm what motor configuration is best.

[Florida_Slotter]

Bane,

There is one sure fire method to determine what will make your car faster.

Change something and run some laps with your car. Take a look at the lap times and see the true result. While a faster motor with more (lower numerical ratio) will give you more top end, it will suffer in the acceleration and braking areas.

The lap timer never lies. It is your friend when used correctly. It is a measure of what is good and what is not good when it comes to tuning your car. Use it and then you will know what works and what does not.

Just my opinion on the subject.