Brushless - OnRoad Gearing

[swalker]

Hi Guys,

My son and I are running JRXS-R cars in OnRoad at our club. I recently bought Novak Brushless motors for them. Our class demands a 17.5T brushless motor. They are so slow.

I now have managed to modify a Kevlar Dual Slipper Spur Gear- 48 pitch, 76 tooth Spur gear to fit and we are using 47T Pinions and we are still amongst the slowest cars there.

Has anyone successfully run a 17.5T brushless motor in any races. What gearing do you need for these snail motors?

[ctg1129]

we run the 17.5 in our vintage trans am class,ive got a HB cyclone with 69t spur and 35 t pinion witch gives me a FDR of 4.19 and it runs fine. where did you get a pinion that big?
i think you might have something wrong because that gear combo will give you a FDR of 2.96 with that it should move.

[swalker]

Stormer Hobbies sells them. They are made by Robison Racing. They go up to 47 tooth.

Unfortinately you can only get them in alloy. I never did in a single spur gear in the whole time I was running steel pinions (and that is in both my sons and my nitro and elect cars).

[da John Wee]

Stormer Hobbies sells them. They are made by Robison Racing. They go up to 47 tooth.

Unfortinately you can only get them in alloy. I never did in a single spur gear in the whole time I was running steel pinions (and that is in both my sons and my nitro and elect cars).
I dont know how big your track is but 2.96 FDR is way too low! (a pinion TOO BIG!)

I went as low as 3.66 once with a trinity 17.5/LRP TC. on 140ft long track. then ppl thought I was crazy!

something wrong there for sure.

check your radio calibration? to make sure you got highspeed on your ESC? maybe?:confused:

[jkirkwood]

Gearing is going to be dependent on many things such as track size and layout, performance you are getting from the batteries, motor timing, and speed controller brand & setup.

If you are running rubber tires then anywhere from a 3.5-4.5 FDR will probably be in the target. I would start probably with a 4.0 FDR and work from there. Check your motor temps after 2 min of running and make sure you are not overheating the motor. For motor temps you should be in the 150-165 deg temp range for a 5-6 minute race but still gear it for laptimes. If your faster laps are with a motor that is running 130 deg so be it.

Also you might want to check to make sure you don't have any binding in the drive train. Make sure all the bearings are funning free and the belts aren't too tight.

[swalker]

Our club runs 27T Stock (17.5T Brushless), Pullstart Nitro, Open class Nitro and 1/5 scale petrol. The track is quiet open and the guys with the 27T brushed motors run their motors geared to run red hot.

My son and I are running the Novak 17.5T & Havoc combo sets. We started at 3.8:1 and kept gearing higher and higher and we are still slow compared to the other cars. This is really annoying my son as when we were running brushed motors, he had gone entire seasons without loosing a race.

[Y2KGTP]

Helpful guide from Novak...

http://www.teamnovak.com/tech_info/brushless/br_gearing.html

[swalker]

It may be that the Havoc controller is not very good for competition, but we did start of at about 3.8:1 and we just had to keep gearing up.

No point in racing if your car is much slower than the other cars. Especially when we can go through the corners faster than the other guys.

[Blacktiger355]

Yeah sounds like something is off on either the radio setup or maybe something else. What is the internal drive ratio on the JRXS?

[swalker]

Guys,

I think that the main problem is that the Novak Havoc controller is "DUMB". Any suggestions as to what controller is most likley to speed up the 17.5T motor?

[da John Wee]

Guys,

I think that the main problem is that the Novak Havoc controller is "DUMB". Any suggestions as to what controller is most likley to speed up the 17.5T motor?

tekin rs. bar none

[SkyRocket]

Guys,

I think that the main problem is that the Novak Havoc controller is "DUMB". Any suggestions as to what controller is most likley to speed up the 17.5T motor?

+1 on the Tekin RS.

[swalker]

I have been looking at the specs of several different controllers and none give any idea what sort of speed gain you would get.

I am getting 2200kV using the Havoc controller with the 17.5T motor. What would you expect the Tekin to take it up to?

[jkirkwood]

What size track you running on? I don't know what KV ratings you will get from the new speedos but there is considerable gain in top speeds. However if your track is really tight and short then the gains are going to be minimal, but just about every speedo is faster than the Havok (IMO).

I would recommend the Tekin RS for spec racing and you will need the hotwire if you are going to get the maxium out of it. If you don't want to carry the laptop the LRP SPX is a very close second.

If the track is short for the turbo features of the above mentioned speedos to be useful the Losi Xcelerin is very good for the cost.

[swalker]

While we are at it, I am running Novak SS17.5 motors. Should I be changing them as well?

[swalker]

LRP claim that they developed a "Stock Spec" version of their SPX controller. Anyone had any experience with them? Are they as good as the Tekin, or is it a marketing ploy?

[Blacktiger355]

I have not tried the new LRP, but many of my fellow local racers use the Tekin. Lets just say I am running a 10.5 at the moment on practice days and the older LRP TC Spec ESC. And their 17.5's are just as fast as I am. A few of the good drivers are actualy faster. Of course car setup, gearing, tires, and driver skill all play a factor in your speed on the track. But down the straight, the Tekin has a clear advantage. It has so many more user adjustable settings by the little Hotwire box and a laptop. And it seems with each firmware upgrade the speed and power increase as well as the Tekin boys figure out how to get more out of their product. My next purchase will be a Tekin RS for sure.

[swalker]

Thanks a heap guys. We will have Tekin esc's in our cars next race days.

[swalker]

Just one last question. is the Pro version worth the extra money, or is there very little difference to the standard RS esc?

[Blacktiger355]

The only main differences between the two is the standard rs has a 5 turn motor limit, and the pro has a lower on resistance. Everything else is the same. Unless you will be running under 5 turns, you do not need the pro.

[swalker]

Thanks. I suspected such. I intend to buy from Stormer Hobbies and they were sold out of the Pro version. As I am running 17.5T motors then it wont make any difference.

I noticed that the Fantom have started making a Vented 17.5T motor. I was wondering if anyone has used them. I like the idea of vented motors. The standard brushless motors cant get rid of the internal heat.

Any comments?

[Blacktiger355]

The Fantom motors are based off the Trinity/Epic Duo motors. And yes they do run a bit cooler. I have a 10.5 Duo that screams and even after long runs still stays under 150. My other motors, losi, novak etc all creap up around 170-180 with the same setup. The only drawback is it will require a little more maintanence. With the vented can, and the exposed bearings, it can get a bit dirty. But it's easy to clean. Just remember to never use standard motor spray on it. Take the motor apart and clean it by hand and blow it out with some air, and if need be a small bristle brush.

[SkyRocket]

Thanks. I suspected such. I intend to buy from Stormer Hobbies and they were sold out of the Pro version. As I am running 17.5T motors then it wont make any difference.

I noticed that the Fantom have started making a Vented 17.5T motor. I was wondering if anyone has used them. I like the idea of vented motors. The standard brushless motors cant get rid of the internal heat.

Any comments?

I have 17.5 and 10.5 Duo 2's in stock now I will restock 10.5 Duo's soon, and I have 17.5 and 13.5 Duo 1's and I have Tekin RS's in stock as well with a couple pros on the way.

I run the Fantom Duo 1's I like them a little better than the 2's because I don't want to guess what degree of timing I have I like the stepped timing the Duo 1's offer. Also the Duo 2's give you a tad more RPM and the Duo 1's give you a tad more torque but I plan on keeping both in stock as long as they make them so it may be a personal preference between the two.

[swalker]

Thanks Skyrocket. I will invest in a couple of the Duo's as soon as I get funding approval from the wife.

I was a little worried about the motor picking up debris. Has that been a problem? At least it would be very hard for the motot to lock with debris.

Do they have a fan and does it load the motor at all?

[SkyRocket]

Thanks Skyrocket. I will invest in a couple of the Duo's as soon as I get funding approval from the wife.

I was a little worried about the motor picking up debris. Has that been a problem? At least it would be very hard for the motot to lock with debris.

Do they have a fan and does it load the motor at all?

I've been running the duo's since they've been released last year and I haven't had any issues w/ debris. I honestly couldn't tell you the last time
even cleaned it. I blow it out w/ air every now and again.

[jkirkwood]

When cleaning the motors only use compressed air and perhaps a soft brush. Don't use any chemicals on the windings and sensors.

[SkyRocket]

Thanks Skyrocket. I will invest in a couple of the Duo's as soon as I get funding approval from the wife.

I was a little worried about the motor picking up debris. Has that been a problem? At least it would be very hard for the motot to lock with debris.

Do they have a fan and does it load the motor at all?

I wouldn't worry about the internals of the motor, it's fast to say the least and based on what has been selling through my shop it is currently the motor to beat.

[swalker]

Skyrocket,

I just ordered 2 of those motors. You are out of stock.

[SkyRocket]

My system is not really the best I must admit. I'm working on it, my budget is -3billion :).

[swalker]

Oh how I wish I could say that.

You need to move to one of the Asian cuntries where a TV can cost hundreds of thousands of their currencies. Then you really could have Billions to play with.

[SkyRocket]

Oh how I wish I could say that.

You need to move to one of the Asian cuntries where a TV can cost hundreds of thousands of their currencies. Then you really could have Billions to play with.

that is a negative 3 billion hahahaaha :)

[swalker]

I fitted my new Tekin RS last night. It made very little difference to the unloaded speed. I wont get a chance to see the effect on the track until next weekend.

They are so small and light compared to my Havoc controller that I had to add weights to the car.

Cant wait til my Fantom motors turn up.

[Blacktiger355]

Have you updated the software on the rs? Or done any timing or boost changes? You may not notice much untill you do.

[swalker]

Yep. Did updates and adjusted the boost to 100%.

Funny, I have a speedo on the vechile and it only spins a few kph faster, running light, but I did a drag race against my sons JRXS with the same gearing, but it had the Havoc esc and I was so much faster. It makes you wonder why they dont just set them to the 30 deg advance as standed.

Something I was wondering, the rs has the ability to be run in duo mode where it swithes to senserless mode at speed. I dont understand how this would be an advantage. Does anyone have any ideas about this one.

[jkirkwood]

It's more an advantage with mod racing, the dual mode. For spec motor racing use the sensored only. My understanding is that senorless is more effecient at high rpm and sensored. Also in dual mode if you loose the sensors during the race then you can keep going. I maybe wrong, Tekin's website probably has a good description of it.

[swalker]

OK, My new Fantom ION 17.5 motors have arrived.

I now have to ask, I am running my RS ESC's at 30 deg advance, should I set the motors to give me more advance?

More advance is supposed to give more RPM, but less Efficiency. Efficiency is not a problem in terms of battery, but may be with heat, but these are ventalated motors and will have a heatsink and fan. But is more than 30 deg too much advance?

[SkyRocket]

OK, My new Fantom ION 17.5 motors have arrived.

I now have to ask, I am running my RS ESC's at 30 deg advance, should I set the motors to give me more advance?

More advance is supposed to give more RPM, but less Efficiency. Efficiency is not a problem in terms of battery, but may be with heat, but these are ventalated motors and will have a heatsink and fan. But is more than 30 deg too much advance?

Do your timing settings based on your temperatures after about 5 laps on the track look for a temp between 160*F and 170*F. I've run 17.5 with 0 timing on the motors and 25 timing boost and max turbo. But again it depends on your track layout and ambient temperature.

[swalker]

Thanks Skyrocket.

The Fantom spins faster than the Novak. I am going to compare with my sons car this afternoon.

Running light with the current gearing, it is showing 65 kmh. This is about the same speed as my brushed motors were showing.

I cant wait till the next race meet. We have been winning the Nitro races, but too slow with the electrics since we went brushless.

Like I said before, The thing I love about this forum is the level of response I get from you guys. Thank you all.

[Blacktiger355]

What type of batteries are you running? NiMh or Lipo? I noticed a big increase in speed and overall power on my brushless motors when I switched to a quality lipo.

[swalker]

What type of batteries are you running? NiMh or Lipo? I noticed a big increase in speed and overall power on my brushless motors when I switched to a quality lipo.

I am running a 40C lipo. It has plenty of get up and go off the line.

[Blacktiger355]

Ok, not the battery then.

[swalker]

I am allowed to spend AU$100 per week on my hobby.

I dont care how much it costs to have the best, I count the cost in weeks not dollars.

For the first time since we went brushless, I actually feel confident that we now have winning cars again. We got rained out last race day, so we still have not had a chance to race against the others.

A really good thing about changing both motors and ESCs is that when we are so much faster, we can show the others the new motors and forget to mention the ESCs. We can keep our edge for longer.

[swalker]

Finally got to run our cars yesterday for the first time with the new gear. They are at least as fast as the fastest other car there.

We are running with an overall gearing of about 3.3 : 1 and the motor reached 129F. So I can gear higher if I need to.

Unfortunately, we only had one race before we got rained out, but I am very pleased with the speed.

Thankyou to all who helped.

I am still having some handling issues, but I think that on certain turns it is grounding the chassis. I will stiffen up the suspension before next race day.

[Steve eaves]

I am allowed to spend AU$100 per week on my hobby.

I dont care how much it costs to have the best, I count the cost in weeks not dollars.

For the first time since we went brushless, I actually feel confident that we now have winning cars again. We got rained out last race day, so we still have not had a chance to race against the others.

A really good thing about changing both motors and ESCs is that when we are so much faster, we can show the others the new motors and forget to mention the ESCs. We can keep our edge for longer.

What is funny on most forums all new cars are doing all they can to move the motor in as far as possible,and center all the weight,they were beat to the punch lol