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Old 07-31-2007, 10:02 AM   #151
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Originally Posted by syndr0me View Post
People have been threatening for years now to tune brushless motors. Where are they?
Well, since a 3.5 is WAY more than any current R/C vehicle needs, you really don't need somebody sitting around trying to extract any more power from it now do ya?

Stock is a whole different issue, the power has limits that are well within the capability of the current chassis, so any stretching of those HP limits will be an advantage.

So in summation: Until Brushless becomes the order of the day for stock, there won't be any "brushless tuners" because there's no demand for them.

But rest assured, many of the motor tuners you're already familiar with are already working on what they'll do when BL becomes the norm.

Adrian is right kids, be careful what you wish for........
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Old 07-31-2007, 10:07 AM   #152
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The overwhelming majority of the racers will choose not to tune but there will always be some who will.

I would catagorize switching between bonded, 12mm sintered, and 13mm sintered rotors depending on track conditions as tuning already. I think most all the time you would want the 13mm sintered rotor, but not always.

Tuning can mean more power, but, mostly to me, it means exactly what you already said, adjusting timing, and powerband possibly effecting gearing, but I dissagree about not gaining performance. The guys who know what they are doing will find an advantage.

They always do.
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Old 07-31-2007, 10:11 AM   #153
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That's cool to hear, I look forward to seeing what they come up with.

From reading, and my own experience, I've found a few things:

If a sintered rotor starts to lose some strength, you may not see it at the start of a race, but can see it start to fade in the last minute or two. I have experienced this personally, and have read a few incidents of it from the oval guys. I have also read where guys have tried 10 different sintered rotors, and while they measure a little different on a meter, generally they perform the same. Older rotors may run a little hotter.

People are using some kind of silver polish to polish their rotors. I don't know if they do it between rounds or what, but I read people are doing it now. I made a joke a long time ago about it, but never in my wildest dreams imagined it would actually be used for "tuning."

Some of the oval guys were trying to "sleeve" their rotors, presumably to change the air gap. I'm not sure if they'll continue with that now that Novak has a 13mm rotor coming out.

I expect oval is where you'll see the tricks first, as speed means more to them. It's definitely worth keeping an eye on.
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Old 07-31-2007, 10:11 AM   #154
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But back to the topic, does anybody else believe that brushless stock lipo could become mod? If it doesnt, we could be down to 4 cells by next year!
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Old 07-31-2007, 10:16 AM   #155
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I would catagorize switching between bonded, 12mm sintered, and 13mm sintered rotors depending on track conditions as tuning already. I think most all the time you would want the 13mm sintered rotor, but not always.
We can probably toss out the bonded rotor, I don't think anybody is really using that if they have the option of using sintered.

Arguably, Novak's new "tuning" rotor is the only tuning option we've seen yet, and that came out after what, a year and a half? We've known since the beginning that you can change a motor with air gap, but don't have a good way to experiment with it since nobody is making rotors. Maybe we'll see tuners offer rotors with sleeves on them so we can change air gap easily.
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Old 07-31-2007, 02:03 PM   #156
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Again lipo and 5 cell and mod need not be addressed here. Im not asking to re-invent the wheel. Just create the next ROAR stock motor rule that would include a brushless motor that would be built to ROAR spec. All the other stuff about speed and costs and what ever is taken care of once a ROAR brushless stock rule comes out. Just like our current ROAR stock motor rule, the guidelines are there.



Does the current ROAR stock motor rule work rigth now? As it has for the last 20+years? I dont ever recall a debate about ROARs stock motor rule. And thats great. Now we need the next generation rule for brushless stock..

Earlier in this thread there was some good considerations for what the rules would contain...

This tuned rotor stuff you mention syndrome could be a thing that is addressed in stock brushless rule set. Perhaps a fixed air gap, fixed cost, certain materials ect ect.
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Old 07-31-2007, 02:11 PM   #157
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Actually, there were plenty of complaints when ROAR came out with the new rules in 91. Then again when they went rebuildable. The thing is, the racers complained about things for a month or two and then went on racing just like before.

ROAR won't please everyone with a new BL motor rule. They'll make pretty much all of the racers mad if they don't make any rules at all. Even the brushed guys are going to be mad when the 13.5's start running in the brushed stock class.

I think that pretty much all the racers agree that the BL and brushed should be different classes.
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Old 07-31-2007, 02:32 PM   #158
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...I could be (and have been before) WRONG, but I personally think that a STOCK B/L motor needs to be quite a bit SLOWER than the 13.5.

With that being said, some of you know I've been involved with testing 17.5 motors and these are much closer to current STOCK speeds, in both 4 cell and 6 cell applications.

Where the 13.5 motor is rated at 3300 KV, I'm going to guess that the 17.5 is closer to 2700Kv and by the feel I'm going to guess around 6-10 watts less power than a 13.5 (which is only about 10 watts less than a 10.5)

The 17.5 motors are built and currently selling directly from NOVAK on their SHOPATRON section at TEAMNOVAK.COM

Currently their is no plan to offer these through normal distribution because it's mainly us OVAL guys who are looking at the use of this motor, BUT I would encourage LOCAL clubs to look at this as your B/L STOCK TOURING MOTOR -

BUY in quantity and save too.

If you get a group to buy 4 of these in one deal, NOVAK is offering them at $5.00 off, plus single shipping price at a savings of close to another $27.00, so that would save 4 guys over $11.00 EACH on this motor.
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Old 07-31-2007, 02:36 PM   #159
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Actually, there were plenty of complaints when ROAR came out with the new rules in 91. Then again when they went rebuildable. The thing is, the racers complained about things for a month or two and then went on racing just like before.

ROAR won't please everyone with a new BL motor rule. They'll make pretty much all of the racers mad if they don't make any rules at all. Even the brushed guys are going to be mad when the 13.5's start running in the brushed stock class.

I think that pretty much all the racers agree that the BL and brushed should be different classes.

I remember that, and the complaints did not last long, as now the mod guys lathes then became a univeral tool, and them stock motor lathes and there not so perfect com cuts where now gone..

If they must be 2 different class so be it, but what im suggesting is to first create the rule. And try to base the rule so that it equates to a similar power of the current stock brushed rules. And to go a step further once the rule had been created ad to it that current ROAR legal brushed motors are allowed to compete in the STOCK BRUSHLESS class. ITs a Politically correct way of creating a new rule for the new era of stock racing that will still allow the brush huggers to race at there local club races or big national events. IT does not have to be one against the other.
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Old 08-17-2007, 04:23 AM   #160
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delete, sorry

Last edited by SWTour; 08-17-2007 at 04:25 AM. Reason: repete message
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Old 08-17-2007, 10:02 AM   #161
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Quote:
Originally Posted by SWTour View Post
Where the 13.5 motor is rated at 3300 KV, I'm going to guess that the 17.5 is closer to 2700Kv and by the feel I'm going to guess around 6-10 watts less power than a 13.5 (which is only about 10 watts less than a 10.5)
SWTour, please throw Kv out of your vocabulary. Kv is RPM's per volt with no load. It's only half of what determines power of a motor. Torque is the other half.

Horsepower (Watts) = RPM x Torque
746 Watts = 1 electric horsepower

Watts of power that a motor generates at 7.2V is the proper way to compare any motor.
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Old 08-17-2007, 11:02 AM   #162
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James,

If you look at most posts I've made...I've described that..but the 3300KV (ie:Unoloaded RPM Per Volt) is what we have/had for a reference.

The only thing I USE that number for is comparison illustrations.

ie: 3300RPMPV x 4.95 volts (4 cell) (16330 rpm)vs 3300RPMPV x 7.43 volts (6 cell) (24500 rpm) both UNLOADED,

I generally figure the LOADED RPM for Oval Racing drops the LOAD RPM to about 50-60% of the UNLOADED RPM in 4 cell, and in 6 cell, closer to a 30-40% RPM drop.

May not be 100% accurate however, IT's been a great bench mark when moving from ONE B/L Motor to another...and the NUMERS are winning races..and making guys go FAST out of the box.

My use of these numbers come from making comparisons to the

3.5 (10,500)
10.5 (4300)
13.5 (3300)

and most of the motors inbetween...in trying to find a starting number for the 17.5 (unknown)
21.5 (unknown)
25.5 (unknown)

I figure the 17.5 should be close to 2700, and I don't remember the 25.5 #'s but I think it was close to 2000, and I'm figuring the 21.5 will be in the 2300-2400 range.

The 21.5 will be run with the 2c LIPO (3200 ORION PACK) so using conservative #'s @ 2300 KV (RPM Per Volt) and about 7.5 volts, the "unloaded" rpm I'm hoping will show to be around 17,250 which should mean approx 9500 RPM Loaded is where I'll start my ROLL OUT for.

TRACK 260 ft' OVAL
TIRE 2.5" (Caps)
LAP TIME 5.7 seconds per lap

speed 45.7 Feet Per Second/ 2736 Feet Per Minute / (31 MPH)

Axle RPM w/ 2.5 tire @ 31 MPH should be close to 4180 (average)

Starting Gear Ratio 2.27 (88/39)

Having NEVER run this motor yet - this will be a starting point - but should require a minimum of probably 3-4 more teeth.

GOTTA Start somewhere
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Old 08-17-2007, 11:18 AM   #163
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SWTour,

I just checked with Adnan----the Kv for the 17.5T is 2200 RPM per volt.
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Old 08-17-2007, 11:35 AM   #164
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NovakTwo

THANK YOU - OUCH!! I guess that means if I use the right KV, I won't have to use as much of a LOAD drop calc...maybe only 25% or so...

What's the 21.5 check out to then...1600 - 1700?

BIGGER GEARS here I come...LOL
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Old 08-28-2007, 09:07 PM   #165
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BUMP and a refresher as to what the topic is.... When will we see a ROAR STOCK BRUSHLESS RULE?


Ok so it looks like BL is the way of the future love it or hate it BL is here. So my club wich i feel is fairly typical is using ROAR as its basis for its club race rulebook.... For the last 17+years of my club racing the biggest class has always been ROAR STOCK. First with pan cars now with touring cars. We have 19T and mod but stock is the one that fills the pits.

We are at a cross roads now with people wanting a to run stock BL in our stock class. And from lots of reading and feedback from this forum, 99% just allow them to run the 13.5BL systems... Thats fine and dandy only novak makes them at this point. the SS and the EX. But as others LRP,GM,CASTLE ect ect get on board with making a 13.5BL we risk blurring the line of what is still considered "stock compatible"

When will we see a ROAR rule book change in regards to the stock class motors??? Fast forward 5 years im sure BL will be the norm and brushed found in RTR cars or even gone. So how do we move forward here?

Mod is taken care of, BL is legal to run in mod. An easy rule to make as mod is about unlimited power, but stock is about limiting power to make it both affordable and slow enough for new racers and even seasoned racers that quite enjoy the lower speeds associated with stock. Not to mention the life of tires and cars is much longer running stock...

So maybe some motor makers and ROAR descision makers could chime in here to perhaps sugest when we may see some sort of stock rules in regards to "STOCK" motor racing.

PS this is not a thread to bash BL VS B. ITs a thread for looking at the future of stock motor racing. As it is now there are no rules or standards. 13.5 is supposed to be equivilent to 27t brush but even with in novaks products the EX vs the SS are totally different in power and speed output..
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