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Old 01-20-2008, 10:55 AM   #76
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Yesterday I had the chance to talk with one of ROAR's executive members. The rules comittee chose 17.5 because it was the reccomendation of the competition/motor comittee. They made that choice based on information provided to them by manufacturers. The only manufacturer who chose to provide any input was Novak. Novak recommended the 17.5, and ROAR agreed, particularly due to the increasing speed of stock racing, both on and off-road.

I agree it's not a fair comparison of motors under the new class structure. If anyone has a problem with it, I guess they should talk to Novak instead.

Last edited by BadSign; 01-20-2008 at 11:06 AM.
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Old 01-20-2008, 11:20 AM   #77
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Your an idiot if you think 13.5 is equivalent to 27t.
Ok, back up your claim. Show me a dyno result. Here I'll even help you out. Here is the link to Novak's brushless spec chart. http://www.teamnovak.com/products/br...spec_chart.htm

Go find a dyno result of a good 27t stocker and back up your claim.

losidriver70,

You didn't answer my question.
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Old 01-20-2008, 11:24 AM   #78
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I am the series director for the ECT an all electric off road series in the NW. We have been running the 13.5 with the Stock Class all winter and it has had mixed results. The top 5 is pretty much all BL. With tight jumps the 13.5 has a definate advantage.

The specs from Novak show it to have more tourque then a p2k ( a great stock truck motor ) and a little less RPM. When geared right it will be a true stock class again. If you want to not tune get a BL and race it if your want to tweak then get a Brushed motor and put your time in.

Through all of the discussion I have read it just sounds as if people don't want to go slower. Step up to a Pro Stock (19t) class then. Out Pro Stock class is for `19t, 13.5, and 10.5.

Our series will be using the 17.5 next season!

Trust me Novak would not put out something that would get eaten alive. That would be bad business.
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Old 01-20-2008, 12:52 PM   #79
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SS13.5 PRO; 195 Watts; 3,300/volt ([email protected])
SS17.5 PRO; 130 Watts; 2,200/volt ([email protected])
[Novak Site]

Reedy MVP; 111 Watts; 29946 RPM
Trinity Monster; 110 Watts; 32645 RPM
Trinity P2K2; 122 Watts; 29506 RPM
[RC-TouringCars.net using CS-Electronic Power [email protected]]
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Old 01-20-2008, 02:05 PM   #80
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Quote:
Originally Posted by theDover View Post
Your an idiot if you think 13.5 is equivalent to 27t.
Sad one has to resort to name calling that not only makes them sound defensive, but seriously weakens they're side of the debate!!!

Let's stick to constructive critisizm instead of name calling!
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Old 01-20-2008, 02:56 PM   #81
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Quote:
Originally Posted by Jake S View Post
SS13.5 PRO; 195 Watts; 3,300/volt ([email protected])
SS17.5 PRO; 130 Watts; 2,200/volt ([email protected])
[Novak Site]

Reedy MVP; 111 Watts; 29946 RPM
Trinity Monster; 110 Watts; 32645 RPM
Trinity P2K2; 122 Watts; 29506 RPM
[RC-TouringCars.net using CS-Electronic Power [email protected]]
If you are trying to prove something based on TOTAL RPM you win. However the 17.5 has a ton more tourque then the MONSTER (wich is ONLY good in a buggy), the MVP wich Sucked period, and the P2K2 wich is also RPM based with low tourque.

Lets compare Apples to Apples

How does it compare to a Tourque specs like the p2k.

We are talking off road wich needs tourque not touring car wich is total RPM

Last edited by Poweredbysbc; 01-20-2008 at 03:09 PM.
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Old 01-20-2008, 05:24 PM   #82
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SS13.5 PRO; 195 Watts; 3,300/volt ([email protected])
SS17.5 PRO; 130 Watts; 2,200/volt ([email protected])
[Novak Site]

Reedy MVP; 111 Watts; 29946 RPM
Trinity Monster; 110 Watts; 32645 RPM
Trinity P2K2; 122 Watts; 29506 RPM
[RC-TouringCars.net using CS-Electronic Power [email protected]]
Thanks for some real data.

From that we can figure a few things out at peak power output.

We know that:

1 watt = 0.001341022 horsepower

&

Torque = (Horsepower * 5252)/RPM

and lets approximate the 17.5's output @ 126 watts @ 7.2 volts.

Using 1 watt = 0.001341022 hp:

P2K2 = .164 hp
17.5 = .169 hp

Using Torque = (Horsepower * 5252)/RPM:

P2K2: 0.0292 ft-lbs
17.5: 0.0560 ft-lbs

You can see that the 17.5 has about twice as much torque as the P2K2 and half the RPM. Now, not knowing the actual output curves of either one and where the peak power is made, we can't nail down a good starting gear ratio.

But from this, we know can see we'll be gearing a 17.5 much higher than a 27t, and we knew that.

This now brings us back to what I posted before for OFFROAD. How are we going to gear these high enough? Spurs cant ge't much smaller than a 78 on an AE without new slipper pads and plates to fit a large enough pinion.

So to everyone that has a properly geared 17.5....where are you finding your 50-60 tooth spurs?
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Old 01-20-2008, 05:46 PM   #83
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Quote:
Originally Posted by Poweredbysbc View Post
If you are trying to prove something based on TOTAL RPM you win. However the 17.5 has a ton more tourque then the MONSTER (wich is ONLY good in a buggy), the MVP wich Sucked period, and the P2K2 wich is also RPM based with low tourque.
p2k2 isn't an rpm based motor...the green machine 3 is trinity's "RPM MOTOR" p2k2 was trinity's "TORQUE MOTOR". co27 has less torque then a p2k2, and less rpm then the gm3.

now numbers from trinity;

CO27 Pro Dyno Readings
RPM: 21,798 (best i have seen as high as 24k)
Power: 65 watts (best i have seen as high as 82)
Efficientcy: 50.5% (best i have seen is 53)
Torque: 100.5 Nmm (best i have seen is 109 - STILL LOWER THEN P2K2)

Torque numbers on a p2k2 are shown at 172Nmm, tell me how that is a low torque motor?

Personally ill agree that a 17.5 will have alot more torque because a 13.5 clearly has much more then a stocker - leading to 4-6 teeth LEAPS in gearing from most brushed stocks, a 17.5 will most likely need 5-7 more teeth over a stock.
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Old 01-20-2008, 06:43 PM   #84
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Quote:
Originally Posted by Jake S View Post
p2k2 isn't an rpm based motor...the green machine 3 is trinity's "RPM MOTOR" p2k2 was trinity's "TORQUE MOTOR". co27 has less torque then a p2k2, and less rpm then the gm3.

now numbers from trinity;

CO27 Pro Dyno Readings
RPM: 21,798 (best i have seen as high as 24k)
Power: 65 watts (best i have seen as high as 82)
Efficientcy: 50.5% (best i have seen is 53)
Torque: 100.5 Nmm (best i have seen is 109 - STILL LOWER THEN P2K2)

Torque numbers on a p2k2 are shown at 172Nmm, tell me how that is a low torque motor?

Personally ill agree that a 17.5 will have alot more torque because a 13.5 clearly has much more then a stocker - leading to 4-6 teeth LEAPS in gearing from most brushed stocks, a 17.5 will most likely need 5-7 more teeth over a stock.
Those numbers from the "CO27 Dyno Readings" are also at around 5 volts (where the labels on cans come from)- the previous dyno readings were all at 7.2 or 7.4. I have to say, gearing a 17.5 to hang w/ a brushed stock motor is going to take a 30/78 combo (B4) and a ton of voltage.
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Old 01-20-2008, 08:01 PM   #85
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With my old TD45 I saw 130Watts at 30A on P2K2's, 125 on P2K's, using 7V. This was consistent with other TD45's according to Jim Greenemeyer. I don't think we have enough info from the Novak site- especially the amp load.
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Old 01-20-2008, 08:31 PM   #86
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I think that the 13.5 when geared correctly is equal to a stock motor. The main problem is the people that are gearing them to the moon which is whats ruining stock. Another thing is that the brushless wont fall off in power over a 6 or 7 minute main. While a stock motor will have the same power as the bl in the beginning, it will have fallen off so much at the end while the 13.5 is stilll the same.
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Old 01-20-2008, 09:53 PM   #87
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Originally Posted by alexb2000 View Post
I think that the 13.5 when geared correctly is equal to a stock motor. The main problem is the people that are gearing them to the moon which is whats ruining stock. Another thing is that the brushless wont fall off in power over a 6 or 7 minute main. While a stock motor will have the same power as the bl in the beginning, it will have fallen off so much at the end while the 13.5 is stilll the same.
All very true- Which again raises the question, why should we de-tune new technology so that it is comparable to old technology? You practice too long w/ a good brushed motor, it gets hot, its never the same. You practice for 15 minutes with a BL 13.5, its fine. Put a new battery in, do it again. For the people who say they have used the 17.5 and it is so 'comparable' to a brushed stock, how are you gearing it? With a 13.5 I have to gear mine 25/78 on my B4 just to have the top speed of a Brushed stock motor at our track.
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Old 01-20-2008, 09:56 PM   #88
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Quote:
Originally Posted by Jake S View Post
SS13.5 PRO; 195 Watts; 3,300/volt ([email protected])
SS17.5 PRO; 130 Watts; 2,200/volt ([email protected])
[Novak Site]

Reedy MVP; 111 Watts; 29946 RPM
Trinity Monster; 110 Watts; 32645 RPM
Trinity P2K2; 122 Watts; 29506 RPM
[RC-TouringCars.net using CS-Electronic Power [email protected]]
your comparing 7.4 to 7.2. thats not gonna work.
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Old 01-20-2008, 10:38 PM   #89
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your comparing 7.4 to 7.2. thats not gonna work.
My post was a mile long, but I took care of that in my previous one. haha

Notice this is ONLY for peak output.
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Old 01-21-2008, 12:31 AM   #90
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I am glad our local track owner decided to keep the 13.5 with the Stock Class this year and even if they do make 13.5 a class by itself next year, there will not be many 27 turn brushed motors left around and will probably have to race with the 13.5 Super Stock Class next year anyway, so what will be different?

Reading between the lines, ROAR is making the transition from brushed racing to ALL BRUSHLESS racing this year and into the future. The Super Stock will be huge next year with Stock dieing out because so many of us already have 13.5s now...why buy a 17.5 to just race at a Nats or Regional.

Should be good time to buy brushed motors and comm cutters cheap!!
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