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Old 01-05-2006, 02:31 PM   #31
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Quote:
Originally Posted by jeffb
John, Erock, those are pretty common numbers for the IB3800's and of the IP3800's latest batches.

Nice eh?
yeah i figured so, my packs are pretty old, all bought back in October.
so I can imagine the newer stuff is showing better numbers.
I know for a fact the IP cells are getting insane like over 530+ runtime at 30 amps. Pretty nice for a supposed 3600 cell since the IP3800 is really a Grepow 3600.
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Old 01-05-2006, 03:36 PM   #32
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Originally Posted by SA_Racer
I use the dos version with all features on ly computer running WinXP , you may have to select compatibilty mode if it gives you problems
thanks all, i will give it a try. I am too young to know DOS ... LOL
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Old 01-05-2006, 05:06 PM   #33
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Jeff-yes, very nice.

erock1331"we run 4 min races

so is the calc right then 43.75 amps ?"

I would have to say yes. One thing that might inflate the number a little are practice laps (add these seconds to your race time), and letting the pack sit a few minutes before the final discharge is done (the pack will self discharge a bit). I imagine the motor would be pretty hot at this level. Have you guys used a temp gun on them. Anyway you should be looking for power watts near this level. Have a buddy do the same test for more verification. Also make sure you have a recent cycle of the T35 as the NiMh tend to loose some capacity with each cycle.

There was one guy at Reflex who was averaging 36 amps in a 6 cell touring car on high grip asphalt.

I used to tune my stock truck (6 cell) on a high grip track for best power right at 45 amps for best lap times, although my average amp draw was much lower.

Last edited by John Stranahan; 01-06-2006 at 07:31 AM.
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Old 01-06-2006, 12:17 PM   #34
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Quote:
Originally Posted by John Stranahan
erock1331"we run 4 min races

so is the calc right then 43.75 amps ?"

I would have to say yes. One thing that might inflate the number a little are practice laps (add these seconds to your race time), and letting the pack sit a few minutes before the final discharge is done (the pack will self discharge a bit). I imagine the motor would be pretty hot at this level. Have you guys used a temp gun on them. Anyway you should be looking for power watts near this level. Have a buddy do the same test for more verification. Also make sure you have a recent cycle of the T35 as the NiMh tend to loose some capacity with each cycle.
We dont run any practice laps, we set the car down and wait for the tone. In oval if you take practice laps then you lose the punch on the first few laps which results in a loss of a tenth per lap up front which is alot.

Actually my packs are pretty dead on for runtime each cycle. I cycle my packs about once every 2 weeks. And they are always 401-414 sec runtime and I always average about 95-105 seconds coming off on the track so I figure we average a normal pack usage of 300 seconds.

Motor temp is around 115-130 degrees
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Old 01-06-2006, 12:32 PM   #35
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In stock we always used 18-26 amps on the robi to test, but if the math is correct then it appears our stockers are pulling more like an average of 27 amps.

on our banked track a runtime pack of 385 comes off with around 195 seconds. So we use about 190 seconds of the pack.

190 x 35 = 6650 / 240 sec-- 27.70 amps
Maybe we should bump up the ave amp calc too look at 23-33 range ?
What do you think?
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Old 01-07-2006, 02:38 AM   #36
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Quote:
Originally Posted by erock1331
In stock we always used 18-26 amps on the robi to test, but if the math is correct then it appears our stockers are pulling more like an average of 27 amps.

on our banked track a runtime pack of 385 comes off with around 195 seconds. So we use about 190 seconds of the pack.

190 x 35 = 6650 / 240 sec-- 27.70 amps
Maybe we should bump up the ave amp calc too look at 23-33 range ?
What do you think?
Sounds like a plan, Unfortunately I wont be able to run my car this weekend but im getting a friend to check his pack and then get back to me on how much he used, hopefully I will be able to tell you guys what were getting by monday.

till later
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Old 01-07-2006, 05:54 AM   #37
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I agree as well. When you tune for the higher range you will end up using a little stiffer springs. Gearig might need to change a little. If lap times don't improve then go back to the previous range. Thanks for posting average amp values. Its been instructive for me.
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Old 02-08-2006, 09:33 AM   #38
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Quote:
Originally Posted by erock1331
In stock we always used 18-26 amps on the robi to test, but if the math is correct then it appears our stockers are pulling more like an average of 27 amps.

on our banked track a runtime pack of 385 comes off with around 195 seconds. So we use about 190 seconds of the pack.

190 x 35 = 6650 / 240 sec-- 27.70 amps
Maybe we should bump up the ave amp calc too look at 23-33 range ?
What do you think?
So I have run a few packs and have calculated that I draw ave 26 amps from my packs during a 5 minute stock race. so This is what I figure.

2/3rds of 26 is 17.3 amps so I round it up to 18 amps 26-18=8 and 26+8=34

so I figure a good range is perhaps from 18 to 34 amps (I know very un-scientific) But I had to decide on an upper limit and 34 sounds like a fair value. The problem I have with this is that the range is probably to broad so I narrowed it by 1 on each end so I set my range to be 19 to 33 amps.

My favorite motors produce around 110 watts in this range and I have found that they are screamers on the track. I also found that going below 106 watts equates to having an average motor on the track.

Also based on this I think one should try tune a motor for max power round the 30A mark

Perhaps you guys can give me your views on what you think could be a good range for measurement, I Believe it is now important to get a broad range for good power delivery at both low speed acceleration as well as on the high speed sections.
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Old 02-08-2006, 11:12 AM   #39
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SA Racer-I think you have a good range especially if motors that exhibit high power in this range are good on the track like you report. Thanks for the numbers.
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