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Old 05-04-2009, 04:30 PM   #256
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I ran my SPX for the first time...As suggested I used profile 8 and went down 2 teeth..48pitch...I found it a bit doughy..but still 2nd qualifier...I went up 1 pinion and advanced the motor...17.5..10degrees.It came alive but temp went from56 to 61 degrees...still OK Still roughly same fastest lap..the guy beating me (same motor..tekin RS pro)went up one more pinioin than me and smoked a brand new motor(trinity)Should I go down 3 or more pinions ? would this give me more power?
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Old 05-06-2009, 02:06 PM   #257
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"no torque" - I don't think so. From about 0 - 12K RPM, profile 2-8 all have the same power. Therefore for any given RPM, they all output the same torque. Profiles 7, and 8 further extend this by giving MORE torque at any RPM higher than approx 12K.
I think the reason for gearing down is to not overheat the motor.

Well done GameOver. I salute you.
Bad choice of words - there is no more torque available as it declines to almost zero at peak revs. I order to get more power, you will need to allow the motor to gain more revs, and that usually means lowering the gearing.

I don't see how the timing can give you more torque, that is a function of the characteristics of a permanent magnet DC motor. Not sure of my theory on this bit, but am sure that unless you take some load off the motor (gear down) you cannot access the higher revs available from the timing change, and it will just convert the current it draws into heat. In that respect we are saying the same thing - if you overload the motor (gear too high) then all the energy drawn by the motor converts to heat, and not more revs.

I wish I'd thought of representing the differences the way GameOver did - so simple... Doh!

Last edited by SlowerOne; 05-06-2009 at 11:39 PM. Reason: Needed it to make sense!!
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Old 05-06-2009, 04:35 PM   #258
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the difference depends on your track and where you can best make time. In all forms of circuit racing i can tell you that the top teams spend most of their time working out how to get thru corners faster than gaining an extra 1 mph on the straights. eg. on my local track generally only 30% of time in a lap is spent at full throttle (mostly in a straight line or slight bends). Improving 30% of your lap by 1% doesn't really add up to much.

The noticeable benefits i find are gearing to smaller pinions gives more braking fine tuning and better throttle control on corner exit and techincal sections for low traction surfaces. This is what is helping me do faster laps with the SPX and not the extra 1mph i have at the end of 3 straights (although that is nice too)
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Old 05-07-2009, 07:44 PM   #259
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Red face Afraid of profile #8?

I thought I would give some observations on Profile#7. Initially ran profile#6 with gearing at 3.9 using my 17.5 Novak. This is a track with a long straightaway and wide sweeper. It definitely had more top speed but no more then other sedans using the TC spec ESC.
So, I went to 4.2 at profile #7, lost a little top speed but gained infield punch and much more brake! Temps were about the same after about 8 min. runs. I was a little disappointed in the performace from #6 to #7. but I didn't give up.
A friend of mine had some new lipo's that he let me try, so I put it in and ran profile #7 and holy sheet! The car was was faster on the straights and in the infield. It seemed as fast than my 13.5. I was able to keep up with other 13.5's on the track and other racers asked what I was running and when I told them a 17.5 they were surprised!
Now I didn't think my lipo's were down on power but I guess in order to get the most out of profile #7 you need the battery that can back up the demand profile #7 requires.
I didn't have a chance to go back to profile #6 and run with the new lipo but I'm sure it too would have made a difference.
I'm thinking about going to #8 but why should I if my 17.5 motor has all the speed that I can handle.
Just my 2$
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Old 05-07-2009, 11:00 PM   #260
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Originally Posted by maxepower View Post
I thought I would give some observations on Profile#7. Initially ran profile#6 with gearing at 3.9 using my 17.5 Novak. This is a track with a long straightaway and wide sweeper. It definitely had more top speed but no more then other sedans using the TC spec ESC.
So, I went to 4.2 at profile #7, lost a little top speed but gained infield punch and much more brake! Temps were about the same after about 8 min. runs. I was a little disappointed in the performace from #6 to #7. but I didn't give up.
A friend of mine had some new lipo's that he let me try, so I put it in and ran profile #7 and holy sheet! The car was was faster on the straights and in the infield. It seemed as fast than my 13.5. I was able to keep up with other 13.5's on the track and other racers asked what I was running and when I told them a 17.5 they were surprised!
Now I didn't think my lipo's were down on power but I guess in order to get the most out of profile #7 you need the battery that can back up the demand profile #7 requires.
I didn't have a chance to go back to profile #6 and run with the new lipo but I'm sure it too would have made a difference.
I'm thinking about going to #8 but why should I if my 17.5 motor has all the speed that I can handle.
Just my 2$
which lipos did you use?
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Old 05-07-2009, 11:20 PM   #261
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which lipos did you use?
They were no name Lipo's. Made in China. Their in a gray plastic hard case with no name on them. So, I couldn't even tell you what MAH. or "C" rating they were. All I know is that they were the size of a 5000mah case but they seemed pretty lite compared to other 5000 lipo's. They were new and had a lot of punch to them.
Speaking of Lipo's, not sure if this is the thread to ask this question but I know Ling is the Lipo expert so maybe he'll read this.
I stored 3 Lipo packs(brand shall remain nameless) in my pitbox for at least a month, I fully charged the batteries before storing. Anyway, I was going through my box cleaning out a few things and happen to open the box where I stored the batteries and all three batteries had swelled up! I put a voltmeter to them and all three read exactly 8.5 volts. Has anybody had this happen to them? I know this wasn't the smartest thing to store Lipo's in a pit bag, they could have caught fire and there goes all my RC stuff. When I put them in storage they all read 8.4 volts. The charger is of good quality and I still use it and it charges at exactly 8.4. My only guess is the batteries got hot sitting in a black pit bad possibly in the sun all day. It has been hot the past few weeks but that's the only thing I could think of?
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Old 05-07-2009, 11:57 PM   #262
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Yes, If you store your lipos fully charged, they will die. Ling told me this.
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Old 05-08-2009, 09:08 AM   #263
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I recently had a chance to push this esc and I can say hands down it's faster than my GTB...by a lot. I would have guessed I was running a 13.5. I was using a TB-03 with a Novak 17.5-Intellect 5000 Lipo...geared it at a 4.0 in Profile #8....Awesome rip...ballistic top end and after 5 minutes motor temp was 130. I am sold!
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Old 05-08-2009, 09:15 AM   #264
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Yes, If you store your lipos fully charged, they will die. Ling told me this.
How long can you keep them fully charged before they start to go bad?
Is temperature a factor when storing them? I thought lipo's liked the heat when charging? I feel like such a novice asking these questions. I don't think I've ever heard of Lipo batteries increasing in voltage from being fully charged.
Maybe MFG. or distributors can specify on how to store Lipo batteries or transport them for that matter!
Just my 2$
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Old 05-08-2009, 12:06 PM   #265
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Originally Posted by maxepower View Post
They were no name Lipo's. Made in China. Their in a gray plastic hard case with no name on them. So, I couldn't even tell you what MAH. or "C" rating they were. All I know is that they were the size of a 5000mah case but they seemed pretty lite compared to other 5000 lipo's. They were new and had a lot of punch to them.
Speaking of Lipo's, not sure if this is the thread to ask this question but I know Ling is the Lipo expert so maybe he'll read this.
I stored 3 Lipo packs(brand shall remain nameless) in my pitbox for at least a month, I fully charged the batteries before storing. Anyway, I was going through my box cleaning out a few things and happen to open the box where I stored the batteries and all three batteries had swelled up! I put a voltmeter to them and all three read exactly 8.5 volts. Has anybody had this happen to them? I know this wasn't the smartest thing to store Lipo's in a pit bag, they could have caught fire and there goes all my RC stuff. When I put them in storage they all read 8.4 volts. The charger is of good quality and I still use it and it charges at exactly 8.4. My only guess is the batteries got hot sitting in a black pit bad possibly in the sun all day. It has been hot the past few weeks but that's the only thing I could think of?
Sounds like they were cheap crap lipo's.

Go for a name brand who will have better warrantee's etc.
Try Thunder Power or SMC.

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Old 05-08-2009, 03:38 PM   #266
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Originally Posted by maxepower View Post
How long can you keep them fully charged before they start to go bad?
Is temperature a factor when storing them? I thought lipo's liked the heat when charging? I feel like such a novice asking these questions. I don't think I've ever heard of Lipo batteries increasing in voltage from being fully charged.
Maybe MFG. or distributors can specify on how to store Lipo batteries or transport them for that matter!
Just my 2$
max... if its the last run for that battery.. i store it after the run.. that means the battery usually has had at least 7mins of runtime used up. ling will chime in shortly...
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Old 05-08-2009, 03:57 PM   #267
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Does anyone use the SPX with a DX3R or Spektrum? At first, I heard there were some compatibility issues, but not as much lately...
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Old 05-08-2009, 03:57 PM   #268
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Originally Posted by maxepower View Post
How long can you keep them fully charged before they start to go bad?
Is temperature a factor when storing them? I thought lipo's liked the heat when charging? I feel like such a novice asking these questions. I don't think I've ever heard of Lipo batteries increasing in voltage from being fully charged.
Maybe MFG. or distributors can specify on how to store Lipo batteries or transport them for that matter!
Just my 2$
Max, I need to respond to this or Hebiki won't stop pestering me.

It's never a good idea to store a lipo battery (or NIMH either) fully charged. The degredation rate goes through the roof when stored that way. Anywhere between 20%-80% is good - it does not need to be that precise.

I've done testing where storing a battery fully charged can kill it in a matter of weeks/months depending on temp while just backing it off to 90% charged keeps them good for years.

High temp is never a good thing for a battery. The general rule of thumb is that for every 10 deg C, the degredation rate of the battery doubles. So storing the battery for 1 year at 20 deg C is the same as storing the battery for 6 months at 30 deg C. When the temps hit over 90 deg F in my garage - I bring my packs indoors. The practice to heat up batteries during charge is to increase performance not for longevity. The combination of high temp and long time is never good.

Lipos do not increase in voltage while being stored...umm...ever. There is something wrong with your charger or multimeter.

Sorry about the off-topic. Back to the SPX thread.
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Old 05-08-2009, 11:36 PM   #269
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Does the spx have polarity protection? if i plug the battery in the wrong direction, will it fly the fets?
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Old 05-08-2009, 11:58 PM   #270
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Originally Posted by linger View Post
Max, I need to respond to this or Hebiki won't stop pestering me.

It's never a good idea to store a lipo battery (or NIMH either) fully charged. The degredation rate goes through the roof when stored that way. Anywhere between 20%-80% is good - it does not need to be that precise.

I've done testing where storing a battery fully charged can kill it in a matter of weeks/months depending on temp while just backing it off to 90% charged keeps them good for years.

High temp is never a good thing for a battery. The general rule of thumb is that for every 10 deg C, the degredation rate of the battery doubles. So storing the battery for 1 year at 20 deg C is the same as storing the battery for 6 months at 30 deg C. When the temps hit over 90 deg F in my garage - I bring my packs indoors. The practice to heat up batteries during charge is to increase performance not for longevity. The combination of high temp and long time is never good.

Lipos do not increase in voltage while being stored...umm...ever. There is something wrong with your charger or multimeter.

Sorry about the off-topic. Back to the SPX thread.
Thanks for the above Ling. Spot on!

What about sex? Sorry, I couldn't resist...Back to the SPX thread.
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