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Old 07-07-2014, 12:02 AM   #61
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Understood, but what you guys fail to understand is that you'll need to gear your 17.5t/7600mah lipo lower than my 17.5t/3300mah lipo combo, eventhough the cars weigh the same... You will be out of the motor's powerband(8300rpm) all the time, and over revving for nothing....You will cook your motor because of too much energy discharge from the 7600 lipo, while I will be running cool...Who remembers cooking stock brushed motors when switching from nimh to lipo???? You don't need a nuclear lipo to run for six minutes!!! You guys run an unbalanced system with too much energy at the start, and when the guys running the lighter packs start figuring this out, they will gear up a bit to make up for the dropoff difference, and you will be left in the dust, cooking even more motors...Also, when the voltage drops a bit, the acceleration becomes smoother, leading to faster laptimes compared to an uncontrollable punchy car.....
CLASS DISMISSED !!!!!!!!.
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Originally Posted by d16dcoe45 View Post
EVERYBODY who raced high level mod used 3300 packs with those 6 & 7 turn motors so they were on a level playing field. My guess is that the voltage/speed difference from start to finish was HUGE but accepted because every car dealt with the same drop-off.

I can see if you have a heavy tub-chassis car wanting to use a shorty or low capacity lipo, but any modern TC with a LW shell can usually make 1380g using a 7500 or 7600 lipo, even if its a minor voltage advantage its still there and it will help in a limited power class.

Last edited by bertrandsv87; 07-07-2014 at 12:29 AM.
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Old 07-07-2014, 12:51 AM   #62
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Bert wrong again mate.

For what it is worth I have always been in favour of the highest capacity lowest IR battery money can buy.
For the first time I am suggesting and preliminary results suggest that a lower capacity although still very large capacity that is lighter is a better option.

295g offers better balance with no extra lead required where as the 7200 and 7600 require ESC to be moved out plus lead to balance the car.

With that being said
7600 pack offers 22.7mAhr per gram
7200 pack offers 21.8mAhr per gram
6000 pack offers 20.3mAhr per gram

7600 pack will provide the best power output over the run.

If I was on a or a high speed track or medium to low traction I would use the bigger battery and use lead to balance the car but I race on a tight high traction track and IMO the lighter battery is better suited.
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Old 07-07-2014, 01:15 AM   #63
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I agree that 300 grams is the ideal lipo weight in TC for close balance to meet ROAR 1380 weight limit. Find the best capacity and lowest IR within that weight limit.
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Old 07-07-2014, 07:25 AM   #64
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I agree that 300 grams is the ideal lipo weight in TC for close balance to meet ROAR 1380 weight limit. Find the best capacity and lowest IR within that weight limit.
My last 2 packs were 330-335g and I will agree with you that 300g is probably the "ideal" max weight for a pack concerning perfect balance while getting to 1380. Running 330-340g packs makes it tougher to get that balance AND stay around 1380.

300g is usually a 6200 pack.
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Old 07-07-2014, 07:39 AM   #65
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"..... You guys run an unbalanced system with too much energy at the start, and when the guys running the lighter packs start figuring this out, they will gear up a bit to make up for the dropoff difference....."



IMO there is NEVER too much energy available in 17.5 sedan and you can't just "gear up" to equal the speed of a motor with more available voltage as you will lose punch out of slow corners AND fade like hell towards the end of the run.

Motors with less wattage and batteries with lower avg. voltage will give less acceleration and less ultimate speed. There is no getting around it. And I can assure you that a 17.5 rpm Killshot with a pink rpm rotor has a much different powerband than a 17.5 Orca TX. That "8300 powerband" is not a universal 17.5 number.

Go to an outdoor asphalt track with a 150'-180' straight and your 3300 lipos & Ballistic will get walked. Point blank period.
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Old 07-07-2014, 11:11 AM   #66
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CLASS DISMISSED !!!!!!!!.
Could you show us a picture of your setup?
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Old 07-07-2014, 11:59 AM   #67
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I am in the process of redoing my 17.5t carpet tc4 to lose the extra 70 grams that was weighing it down last season... I was geared at 3.4375fdr last season with the extra weight, and I did not give anything on the straights or the infield. Another driver drove my car, and said it had lots of torque, and no heat fade, so for next season I will be gearing even higher at 3.2 fdr with the weight loss, and we will know soon whose theory was correct guys....I am convinced I am right , but you guys are entitled to your opinions too, but maybe my approach is only possible in a free shaftdrive car....We'll see soon enough....
By the way, my new setup will include a novak impact esc, ballistic 17.5t with 12.5 mm rotor(polished)+ ceramic bearings, futaba bls551 low profile servo, spektrum receiver, cut motor mount, R1 wurks fan......
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Old 07-07-2014, 12:21 PM   #68
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How are u cutting 70grams out of a tc4? Hacking it up? If your running a lightweight battery even a club racer is right around minimum weight losing 70 grams is a lot of lead to add back to a chassis
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Old 07-07-2014, 12:42 PM   #69
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I am in the process of redoing my 17.5t carpet tc4 to lose the extra 70 grams that was weighing it down last season... I was geared at 3.4375fdr last season with the extra weight, and I did not give anything on the straights or the infield. Another driver drove my car, and said it had lots of torque, and no heat fade, so for next season I will be gearing even higher at 3.2 fdr with the weight loss, and we will know soon whose theory was correct guys....I am convinced I am right , but you guys are entitled to your opinions too, but maybe my approach is only possible in a free shaftdrive car....We'll see soon enough....
By the way, my new setup will include a novak impact esc, ballistic 17.5t with 12.5 mm rotor(polished)+ ceramic bearings, futaba bls551 low profile servo, spektrum receiver, cut motor mount, R1 wurks fan......
Well I'm not sure about everyone else but if your ever at my end of the world and feel like coming to a club race. You may borrow my electronics and run them for the night. That should be more than enough proof.
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Old 07-07-2014, 01:10 PM   #70
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Originally Posted by d16dcoe45 View Post
"..... You guys run an unbalanced system with too much energy at the start, and when the guys running the lighter packs start figuring this out, they will gear up a bit to make up for the dropoff difference....."



IMO there is NEVER too much energy available in 17.5 sedan and you can't just "gear up" to equal the speed of a motor with more available voltage as you will lose punch out of slow corners AND fade like hell towards the end of the run.

Motors with less wattage and batteries with lower avg. voltage will give less acceleration and less ultimate speed. There is no getting around it. And I can assure you that a 17.5 rpm Killshot with a pink rpm rotor has a much different powerband than a 17.5 Orca TX. That "8300 powerband" is not a universal 17.5 number.

Go to an outdoor asphalt track with a 150'-180' straight and your 3300 lipos & Ballistic will get walked. Point blank period.
A track like Full throttle here in Florida..... I don't care what sort of weird-science someone wants to apply. a 3300 / Ballistic (or any other motor) combo will be eaten alive. Having worked the tech station for the pre-worlds, I can assure you that no one is attempting to run low MAH packs. If the best in the business thought this actually worked, you would be seeing it. End of.
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Old 07-07-2014, 02:21 PM   #71
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Originally Posted by bertrandsv87 View Post
I am in the process of redoing my 17.5t carpet tc4 to lose the extra 70 grams that was weighing it down last season... I was geared at 3.4375fdr last season with the extra weight, and I did not give anything on the straights or the infield. Another driver drove my car, and said it had lots of torque, and no heat fade, so for next season I will be gearing even higher at 3.2 fdr with the weight loss, and we will know soon whose theory was correct guys....I am convinced I am right , but you guys are entitled to your opinions too, but maybe my approach is only possible in a free shaftdrive car....We'll see soon enough....
By the way, my new setup will include a novak impact esc, ballistic 17.5t with 12.5 mm rotor(polished)+ ceramic bearings, futaba bls551 low profile servo, spektrum receiver, cut motor mount, R1 wurks fan......
Well its a good thing you polished the rotor, of all the go-fast tricks a guy can do, "polishing" the rotor is always #1 on my list.
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Old 07-07-2014, 02:56 PM   #72
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Well its a good thing you polished the rotor, of all the go-fast tricks a guy can do, "polishing" the rotor is always #1 on my list.
Well, I mean you need to smooth out any surface irregularities... minimum aerodynamic resistance, of course. Not to mention the sheer power you can then extract from those lower MAH packs Going fast and looking good!
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Old 07-07-2014, 04:41 PM   #73
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Well, I mean you need to smooth out any surface irregularities... minimum aerodynamic resistance, of course. Not to mention the sheer power you can then extract from those lower MAH packs Going fast and looking good!
lol! Agreed!
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Old 07-07-2014, 11:13 PM   #74
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I had a full size futaba servo in there and a novak gtb2 esc also.... Those two account for at least 50grams more than the new electronics, and the new spectrum receiver should get it down another 10grams in addition to the 10grams cut off the motor mount.... I also plan to shorten a few wires here and there, and lay them down as much as possible.....Guys, don't be too hard on Bert when he passes you....lol...... My tc4.1 will be awesome at 3.1976fdr....If my car is still overweight after all these changes, I will use the 2700mah (168gram) pack to lose another 40 grams......
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How are u cutting 70grams out of a tc4? Hacking it up? If your running a lightweight battery even a club racer is right around minimum weight losing 70 grams is a lot of lead to add back to a chassis

Last edited by bertrandsv87; 07-07-2014 at 11:43 PM.
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Old 07-07-2014, 11:43 PM   #75
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I have been reading everything that is being said on this thread and researching different batteries, parts, bodies ect.

I need to use the Orca 6200mah LiPo (or Intellect equivalent), protoform lightweight body (with minimal stickers, lightly painted), titanium screw kit and replacing a few steel parts with aluminium. Will also be shortening wires, body posts and using an antenna-less receiver (which is 8g lighter than my current and I can remove the antenna mount and antenna tube). I wont need any lead weight (I don't care if one side is 10g heavier) and won't have to spend a lot of money that would be better served put towards a better car.

I estimated I can get the tb04 pro II to about 1410g this way, that's a number I can live with
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