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Old 08-02-2005, 08:10 PM   #1
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Default Stock Motors (Where's The HP?)

Ok, I have had this conversation with several racers here and there and they have been in agreement with me though unable to help. Here is my issue.

I can't seem to do ANYTHING to a stock motor to improve it beyond what it is right out of the package. I have easily been through 10+ brushes and every spring I can find with virtually NO CHANGES on the dyno at all.

The motors in question would be your basic off the shelf green can Monster stocks from good old Trinity. Some were "pro" motors some where just normal, they are all the same.

My case in point, a test I ran today (numbers are on my Fantom running off of a 75amp power supply with the aluminum flywheel).

I took a motor that has not been spun in nearly a year and was left dirty (we are talking green tarnish on the hoods) and oiled it up and strapped it up:

About 58 Watts
About 21,000 RPM

Took this same motor, tore it down, cut it, re-aligned the hoods to the comm, put on fresh brushes oiled her up and broke her in then strapped it up on the dyno:

About 58 Watts
About 21,000 RPM

When viewing the charts the only difference I see is more efficiency and a smoother power curve on the top end. WHAT ON EARTH AM I DOING WRONG?

If anyone has any ideas please post them in here, I just refuse to think there is nothing I can do to build HP.

Thanks, Nick
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Old 08-02-2005, 08:14 PM   #2
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I would try more combinations and continue to Dyno. I'm sure you are forgetting something.

Besides........ it's all about gearing......

Jeff
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Old 08-02-2005, 11:45 PM   #3
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Your flywheel dyno doesn't show what your motor does under load (like when you're racing).

Why don't you make your changes and run a few laps up and down the street, then see if you're making progress. Track is the best indicator.
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Old 08-02-2005, 11:45 PM   #4
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PM Nick
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Old 08-02-2005, 11:50 PM   #5
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Do you have a friend with a Dyno who can verify the results? It could be a problem with the Dyno or the Software even..

Even if you had access to a motor checker you could use to verify the results, you should see differences in rpm and current draw - no two motors would be totally identical..
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Old 08-03-2005, 06:34 AM   #6
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After you cut the com, take a set of digital calipers and measure the com from top to bottom. Make sure it measures the same all the way from top to bottom.

Typically I find that when people are not getting better results after cutting a motor is because their com lathe is off and making the com out of round.
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Old 08-03-2005, 06:35 AM   #7
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Also not sure your level of motor knowledge, but somebody gave me this reference when I started.

Take a look, this article definately helped me a ton

http://www.motortuningsecrets.com/tunestockmotor.html
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Old 08-03-2005, 10:11 AM   #8
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Quote:
Originally Posted by handyrandyrc
Your flywheel dyno doesn't show what your motor does under load (like when you're racing).

Why don't you make your changes and run a few laps up and down the street, then see if you're making progress. Track is the best indicator.
I agree 100% but that gets a little tough in the middle of winter with a 12th scale car

I will be attending some larger events this year and track time will be quite limited, I really want to get a handle on coming up with HP before I get my car on the track.

Nick
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Old 08-03-2005, 10:12 AM   #9
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Quote:
Originally Posted by v0rtex
Do you have a friend with a Dyno who can verify the results? It could be a problem with the Dyno or the Software even..

Even if you had access to a motor checker you could use to verify the results, you should see differences in rpm and current draw - no two motors would be totally identical..
I will say nothing has been identical, just extremely close. It never seems to matter what brushes or springs I am running, the numbers are incredibly close and nothing seems to "break out" and really perform.

Nick
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Old 08-03-2005, 10:14 AM   #10
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Quote:
Originally Posted by erock1331
After you cut the com, take a set of digital calipers and measure the com from top to bottom. Make sure it measures the same all the way from top to bottom.

Typically I find that when people are not getting better results after cutting a motor is because their com lathe is off and making the com out of round.
I am a very anal retentive guy

My lathe is running very true (it's very new to be honest), after a quick measure and giving the brushes a feel in the running motor the comm appears to be round.

As far as what I know, I wouldn't call myself an expert but I know my way around a motor and I understand the proper way to do things.

Nick
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Old 08-03-2005, 10:17 AM   #11
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On my fantom dyno, a Trinity Pro monster started out at about 57-60 watts. I ended up trying alot of different brush spring combos, and every motor I had worked best with 767's and red springs. About 63-65 watts.
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Old 08-03-2005, 11:03 AM   #12
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did you try dynoing the motor on somebody else's dyno.
maybe something is up with the dyno ??

I know several people with Fantom dyno's a 60 watter can be a 65 on another which can be a 72 watter on another.

They all read a bit different.
I used to have a robi dyno, the numbers were not as off as a fantom but they still varied from dyno to dyno.

just a thought
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Old 08-03-2005, 12:48 PM   #13
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Put on a 19turn or mod motor. If the numbers don't jump bigtime then your dyno needs to be serviced.
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Old 08-03-2005, 12:57 PM   #14
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I did bolt up a 19 to make sure the dyno would read numbers higher than what I was seeing and it will. I understand everyone's dyno is different but I should be able to do something to a motor to increase the numbers, that's really the issue here.

I will replace the red/green combo on that monster and run it again and the curve will look almost identical. Nothing seems to make any sizable change and I have tried almost everything!!

Thanks for the help guys,
Nick
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Old 08-03-2005, 06:07 PM   #15
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you could recheck the shiming on the motor because if it's off alittle it could cost you some watts and eff .all those machine wound motors don't come perfectly shimed it's worth a shot..
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