I ran 21.5/Lipo (BRL Rules 3200 SMC) for the first time this past weekend and had a few questions.

The lap times seemed to drop off more than I had anticipated. I was losing about .25 per lap from the beginning to the end. I was using approx 1100mah per run. The motor was coming off the track around 150 degrees. I did not cycle the packs before I got to the track. I did run the pack several practice runs and and ran 3 heats and a main. I recharged the pack between each run. The pack was charged on a GFX at 5.0 amps. Any thoughts?

I was also confused in the gearing because I was not able to gear as high as I could in 13.5 as the motor would push 160 degrees when I got close to the same gearing I ran in 13.5. Thanks. Bob

The LiPOs falloff more than NiMH. I'd say .25 per lap is pretty normal.

I think a higher motor temperature is going to be the norm with the LiPOs. At least that is what I noticed so far.

The LiPOs falloff more than NiMH. I'd say .25 per lap is pretty normal.

I think a higher motor temperature is going to be the norm with the LiPOs. At least that is what I noticed so far.

I thought I had heard or read somewhere that Lipo's do not have a discharge curve like a Nimh pack and would run pretty much the same lap times until they are dead. I guess I was misguided. I feel better now. Thanks Pat.

I thought I had heard or read somewhere that Lipo's do not have a discharge curve like a Nimh pack and would run pretty much the same lap times until they are dead. I guess I was misguided. I feel better now. Thanks Pat.

Yeah that was a myth that went around for awhile. The curve is actually a fair amount steeper with the LiPOs.

BRhodes, it is just as pmsimkins said, we are seeing about .3 to .4 drop down here in FLa but we are running 5 min races.

I was losing about .25 per lap from the beginning to the end.

.25 PER LAP Something is WRONG if you are dropping .25 PER LAP from the beginning to the end. That would be a ONE second loss every 4 laps.

Here's two runs from our CARPET Race on Saturday.

In the first race, Andrew Acosta was running his "BRL" car w/ SMC battery and spoiler, etc. (I made him change that to a ORION per our rules for the following heats)

Bryan Blaser's 72 lap run was TQ and the ONLY 72 lap run of the day. (NOTE: This is 21.5/LIPO)


South-West Tour Series -- Race 8 -- Carpet @ LINDSAY

Race# 3 -- 21.5 Stock - Heat #3 round 1 --
Pos Car Laps time name id avg.mph
1 3 71 5:02.16 Andy Acosta 6 25.63
2 4 70 5:02.45 Carlton Duty 3 25.25
3 2 69 5:03.99 Keith Brown 20 24.76
4 1 68 5:03.06 Steve Jacquez 36 24.48
5 5 64 5:02.44 Lou Maldonado 32 23.08
Nipomo 9/7 09-13-2008

-- RACE #3 - 21.5 Stock - Heat #3 Round 1 --
Car-> __1__ __2__ __3__ __4__ __5__ __6__ __7__ __8__ __9__ __0__
1 3.37 3.82 3.66 3.60 4.68
2 4.31 4.42 4.37 4.24 4.49
3 4.47 4.33 4.20 4.15 4.51
4 4.28 4.32 4.43 4.28 4.45
5 4.34 4.25 4.17 4.09 4.43
6 4.52 4.56 4.52 4.23 4.50
7 4.42 4.48 4.24 4.34 4.49
8 4.44 4.21 4.13 4.29 4.42
9 4.28 4.29 4.10 4.02 4.46
10 4.60 5.20 4.16 4.20 4.57
11 4.42 4.76 4.14 4.10 4.42
12 4.35 4.46 4.08 4.26 8.79
13 4.65 4.81 4.22 5.59 4.71
14 4.37 4.28 4.34 4.22 4.75
15 4.28 4.43 4.34 4.05 5.32
16 4.44 4.27 4.24 4.22 4.40
17 4.31 4.28 4.15 4.26 4.40
18 4.27 4.34 4.12 4.15 4.44
19 4.36 4.45 4.12 4.20 4.43
20 4.27 4.44 4.15 4.28 4.58
21 4.31 4.26 4.17 4.16 4.67
22 4.46 4.33 4.20 4.25 4.78
23 4.37 4.26 4.23 4.16 4.62
24 4.31 4.38 4.21 4.22 4.68
25 4.42 4.52 4.13 4.15 4.54
26 4.51 4.26 4.22 4.20 4.65
27 4.23 4.50 4.24 4.38 4.50
28 4.56 4.63 4.30 4.86 4.60
29 4.35 4.29 4.20 4.65 5.15
30 4.49 4.45 4.19 4.30 4.55
31 4.36 4.55 4.20 4.26 4.71
32 4.35 4.44 4.22 4.39 4.63
33 4.45 4.34 4.24 4.34 4.77
34 4.50 4.41 4.23 4.21 4.90
35 4.35 4.28 4.23 4.19 4.52
36 4.31 4.39 4.28 4.31 4.64
37 4.42 4.27 4.35 4.23 4.53
38 4.53 4.36 4.25 4.39 4.49
39 4.34 4.34 4.24 4.21 4.58
40 4.58 4.29 4.24 4.32 4.55
41 4.60 4.35 4.23 4.26 4.56
42 4.42 4.34 4.23 4.51 4.54
43 4.41 4.51 4.26 4.27 4.52
44 6.40 4.49 4.21 4.42 4.67
45 4.59 4.45 4.34 5.41 4.58
46 4.66 4.42 4.38 4.43 4.91
47 4.46 4.68 4.33 4.63 4.74
48 4.60 4.36 4.29 4.23 4.87
49 4.53 4.40 4.33 4.33 4.64
50 4.36 4.40 4.29 4.36 4.75
51 4.35 4.34 4.25 4.28 4.72
52 4.52 4.42 4.24 4.25 4.87
53 4.48 4.36 4.29 4.40 4.75
54 4.51 4.30 4.28 4.32 4.51
55 4.40 4.35 4.27 4.33 4.69
56 4.40 4.29 4.23 4.24 5.92
57 4.56 4.42 4.28 4.30 5.00
58 4.38 4.36 4.33 4.22 4.59
59 4.55 4.40 4.28 4.27 4.63
60 4.33 4.33 4.32 4.38 4.69
61 4.45 4.36 4.37 4.52 4.65
62 4.41 4.33 4.28 4.32 4.72
63 4.57 4.48 4.31 4.28 4.56
64 5.09 4.37 4.27 4.34 4.73
65 4.46 4.49 4.30 4.25
66 4.46 4.37 4.49 4.29
67 4.45 4.53 4.34 4.33
68 4.34 4.42 4.29 4.30
69 4.37 4.36 4.43
70 4.35 4.28
71 4.35
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____
laps 68 69 71 70 64
time 303.0 303.9 302.1 302.4 302.4
Min 3.37 3.82 3.66 3.60 4.40

South-West Tour Series -- Race 8 -- Carpet @ LINDSAY

Race# 4 -- 21.5 Stock - Heat #4 round 2 --
Pos Car Laps time name id avg.mph
1 3 72 5:04.36 Bryan Blaser 7 25.81
2 1 71 5:02.76 Tony Gammel 39 25.58
3 5 67 5:00.66 Arnold Brittain 41 24.31
4 4 66 5:03.78 Randy Smith 28 23.70
5 2 8 0:46.75 Scot Petitclerc 14 18.67
Nipomo 9/7 09-13-2008

-- RACE #4 - 21.5 Stock - Heat #4 Round 2 --
Car-> __1__ __2__ __3__ __4__ __5__ __6__ __7__ __8__ __9__ __0__
1 3.55 3.94 3.22 3.93 5.19
2 4.15 8.48 3.98 4.49 4.41
3 4.09 11.90 3.97 4.41 4.15
4 4.07 4.76 4.03 4.38 4.30
5 4.06 4.09 4.14 4.38 4.10
6 4.08 4.20 4.17 4.32 4.31
7 4.10 4.80 4.09 4.34 4.18
8 4.11 4.53 4.20 4.35 4.27
9 4.09 4.11 4.26 4.23
10 4.15 4.07 4.41 4.18
11 4.11 4.06 4.92 4.63
12 4.17 4.19 5.11 4.33
13 4.29 4.29 4.64 4.27
14 4.13 4.13 4.27 4.55
15 4.19 4.17 4.60 4.23
16 4.15 4.06 4.51 4.23
17 4.30 4.14 4.72 4.24
18 4.19 4.15 4.34 4.55
19 4.23 4.17 4.31 4.42
20 4.24 4.11 4.45 4.28
21 4.22 4.25 4.34 4.22
22 4.24 4.27 4.44 4.26
23 4.20 4.15 4.90 4.42
24 4.25 4.19 4.60 4.26
25 4.21 4.33 4.39 4.29
26 4.26 4.32 5.01 4.26
27 4.21 4.18 4.59 4.23
28 4.34 4.16 5.39 4.43
29 4.18 4.11 4.48 6.69
30 4.23 4.17 4.43 4.42
31 4.25 4.27 4.34 4.36
32 4.28 4.31 4.40 4.25
33 4.24 4.14 4.47 4.25
34 4.25 4.25 4.65 4.29
35 4.22 4.33 4.53 4.50
36 4.28 4.22 4.51 4.29
37 4.32 4.37 4.42 4.35
38 4.21 4.23 4.45 4.48
39 4.31 4.30 4.34 4.71
40 4.31 4.38 4.50 4.50
41 4.61 4.31 4.66 4.44
42 4.32 4.22 4.94 4.43
43 4.29 4.23 4.73 4.32
44 4.38 4.32 4.61 4.36
45 4.34 4.33 4.56 6.26
46 4.32 4.26 4.40 4.86
47 4.29 4.19 4.57 4.46
48 4.30 4.27 4.45 4.44
49 4.27 4.29 5.11 4.62
50 4.33 4.24 5.35 4.46
51 4.30 4.26 5.85 4.48
52 4.32 4.25 4.50 5.31
53 4.28 4.23 4.67 4.37
54 4.29 4.20 4.66 4.50
55 4.54 4.41 5.23 4.41
56 4.35 4.25 4.55 4.30
57 4.36 4.29 4.48 4.69
58 4.30 4.30 4.52 4.71
59 4.34 4.23 4.58 4.39
60 4.36 4.34 4.47 4.99
61 4.32 4.27 4.69 4.37
62 4.44 4.21 4.72 4.52
63 4.34 4.32 4.87 4.60
64 4.39 4.31 4.60 4.32
65 4.29 4.34 4.75 4.35
66 4.33 4.75 4.59 4.53
67 4.45 4.39 4.38
68 4.44 4.34
69 4.36 4.21
70 4.35 4.31
71 4.33 4.34
72 4.42
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____
laps 71 8 72 66 67
time 302.7 46.74 304.3 303.7 300.6
Min 3.55 3.94 3.22 3.93 4.10




Here's the TQ Run for the 17.5/LIPO Class


South-West Tour Series -- Race 8 -- Carpet @ LINDSAY

Race# 8 -- 17.5 Limited - Heat # 2 round 3 --
Pos Car Laps time name id avg.mph
1 2 78 5:03.38 Gary Hamilton 15 28.05
2 3 77 5:00.97 Erik Steenhoven 18 27.91
3 4 76 5:00.59 Jason Hastings 37 27.58
4 5 76 5:02.19 Eric Brust 31 27.44
5 1 75 5:02.27 Scot Petitclerc 13 27.07
Nipomo 9/7 09-13-2008

-- RACE #8 - 17.5 Limited - Heat # 2 Round 3 --
Car-> __1__ __2__ __3__ __4__ __5__ __6__ __7__ __8__ __9__ __0__
1 3.43 2.80 3.22 3.01 3.72
2 3.92 3.73 3.80 3.91 3.97
3 3.87 3.78 3.83 3.87 3.79
4 3.86 3.79 3.81 4.12 3.82
5 3.90 3.85 3.87 3.86 3.85
6 3.91 3.77 3.85 3.86 3.91
7 3.84 3.83 3.79 3.87 3.93
8 3.88 3.80 3.87 3.98 3.87
9 3.89 3.76 3.82 3.86 3.86
10 3.86 3.80 3.82 3.89 3.87
11 3.92 3.82 3.84 3.85 3.90
12 3.89 3.80 3.84 3.88 3.87
13 3.91 3.76 3.84 3.82 3.89
14 3.84 3.89 3.84 3.87 3.85
15 3.91 3.79 3.81 3.91 3.88
16 3.90 3.84 3.81 3.94 3.89
17 3.90 3.93 3.92 3.84 3.90
18 3.87 3.83 3.87 3.91 3.90
19 4.01 3.89 3.89 3.94 3.90
20 3.91 3.88 3.84 3.85 3.97
21 4.37 3.86 3.87 3.90 3.97
22 4.39 3.87 3.87 3.91 4.23
23 3.94 3.87 3.86 3.94 3.94
24 3.94 3.82 3.89 4.00 3.95
25 4.06 3.89 3.93 3.96 3.91
26 3.90 3.87 3.91 3.86 3.91
27 3.95 3.86 3.87 4.02 3.96
28 3.89 3.82 3.90 4.04 3.94
29 3.96 3.88 3.86 3.89 3.96
30 4.27 3.85 3.93 4.01 3.94
31 3.93 3.92 3.90 4.00 3.97
32 3.94 3.84 3.93 3.91 3.94
33 3.98 3.84 3.91 3.89 3.98
34 4.03 3.90 3.90 3.90 4.02
35 3.92 3.86 3.97 3.99 4.30
36 4.12 3.94 3.90 4.00 3.99
37 3.91 3.91 3.93 4.02 3.96
38 4.01 3.89 3.99 4.09 3.94
39 3.95 3.89 3.89 4.24 3.99
40 3.98 3.94 3.92 4.08 3.98
41 3.94 3.93 3.89 4.18 3.99
42 3.98 3.98 4.02 4.08 3.96
43 3.98 3.91 3.93 4.01 3.96
44 3.97 3.89 3.91 3.95 3.92
45 3.99 3.86 3.97 3.95 3.99
46 4.03 3.90 3.91 3.95 3.94
47 4.40 3.94 3.93 3.92 4.01
48 4.07 3.97 3.92 3.94 3.95
49 4.00 3.97 3.96 3.90 3.99
50 4.11 3.87 3.93 3.90 4.00
51 4.02 3.94 3.91 3.94 4.00
52 4.06 3.90 3.94 4.00 3.99
53 4.01 3.93 3.96 3.91 4.04
54 4.00 3.93 3.93 4.08 4.02
55 4.02 3.90 3.92 3.94 3.96
56 4.00 3.96 3.95 4.02 3.97
57 4.04 4.04 3.98 3.91 4.02
58 3.96 3.98 3.99 3.98 4.04
59 4.02 3.93 3.99 3.93 4.00
60 4.21 3.93 3.95 3.99 3.97
61 4.13 3.95 3.97 4.13 4.25
62 4.09 3.88 3.94 4.04 4.09
63 4.06 3.99 3.92 3.93 4.00
64 4.13 3.91 3.98 3.98 3.97
65 4.47 3.94 3.94 3.92 4.01
66 4.05 3.99 3.96 3.97 4.02
67 4.01 3.98 3.96 3.96 4.07
68 4.07 3.95 4.00 3.96 4.08
69 4.03 3.93 3.94 4.03 4.07
70 4.05 4.04 3.93 3.95 4.06
71 4.01 3.98 3.98 3.94 4.01
72 4.02 3.98 3.96 4.01 4.00
73 4.11 4.00 3.99 4.01 3.99
74 4.71 3.94 3.92 4.01 4.09
75 5.28 3.94 3.99 4.15 4.05
76 4.00 4.04 4.06 4.04
77 4.04 3.97
78 4.00
_____ _____ _____ _____ _____ _____ _____ _____ _____ _____
laps 75 78 77 76 76
time 302.2 303.3 300.9 300.5 302.1
Min 3.43 2.80 3.22 3.01 3.72

Gary ran a 3.73 on the first and a 4.00 on the last...and (incase you didn't notice) We also run 5 minutes...and THESE are all ORION 3200's except Andy Acosta's first run.

Yeah that was a myth that went around for awhile. The curve is actually a fair amount steeper with the LiPOs.
My take on it is that the curve is steeper partly because you are using a greater percentage of the 3200 LiPo pack than a 4600 NiMh pack.

A LiPo starts off at 8.4 and we can safely take them down to 6.0 for a total drop of 2.4V.

A NiMh, for practical purposes starts off at 1.3V/cell (peak voltage on charger doesn't really count - within 1 second of discharge, the voltage is down to about 1.3V). We take them down to .9V/cell So that is .4V per cell and for a pack equivalent to a LiPo, a 6-cell pack, that would be 2.4V - pretty close to the same.

So it looks like, percentage wise just on voltage, LiPo has a smaller drop from full to empty (2.4/8.4*100 => 28%) than NiMh (2.4/7.8*100 => 30%). I bet the times wouldn't drop off so much if you were using a LiPo with a capacity comparable to the current NiMh cells. You are using a greater percentage of the pack's capacity and that may be why you see more drop-off. (Comparing brushless to brushless.)

Joe, he meant .25 start to finish.

edited

Everything on HT is required to be a battle isn't it. :rolleyes:

edited

edited - Here in a nutshell was one of the 21.5 "A" main cars with a EagleTree Data Logger capturing AMPS and VOLTAGE.

LOADED NUMBERS
8.15v - 0.00a - Sitting on line before the tone
7.49v - 44.89a - Off the LINE (at the tone)
7.70v - 23.86a - 1st Lap
7.29v - 21.27a - 90 seconds into race
7.03v - 20.65a - final laps (at 5 min. mark)
7.23v - 0.00a - parked on track after race

Battery Used 1523 mAh

Joe, he meant .25 start to finish.

Thanks Pat. Sorry for the confusion. LOL

I too se car #3 with avg 4.0 out the gate and 4.3 out back thats .25 avg to me..LOL

I too se car #3 with avg 4.0 out the gate and 4.3 out back thats .25 avg to me..LOL


I was losing about .25 per lap

It didn't say he lost .25 from start to finish. It said .25 PER LAP

Personally, I was pretty sure what he meant...but it COULD have been what he actually SAID, then as I STATED it would have been something REALLY wrong.

I would actually say, closer to .4 from start to finish (Which on this track would be about a 10% drop), and looking at the LOADED Voltage on the FIRST LAP 7.70v and the Voltageg on the LAST Lap 7.03v which is also virtually a 10% drop, I'd say the times were on the money for the drop %

swtour, do you know what Bryan was running for a gear combination?

napolean,

no clue...I know we ran around a mid 3 rollout. 3.57 - 3.68, but we had NOTHING for Blaser.

Thanks, I was curious, since we run the same basic lap times on our track, but the roll outs are all over the map, so are the gear combos...some 88, some 100, some 114s'. These motors seem to have that mysterious sweet spot combo of timing, temp, and gear! It's not just corner speed, it's more speed, period, not much more, but enough to make you keep looking for more.

I believe my cars were running 100's. I usually bounce between the 88's and the 100's.

Joe,why the big gap between 21.5 and 17.5? should be around 3-3.5 laps between good cars? What are gary and Eric using for power in 17.5 class? 21.5 should have been around 74-75 lap run?

Why do you think the 21.5 cars should be running 74-75 laps? Everybody uses the Orion batt.

Jason,pretty much what i've seen on different tracks that the difference has been 3-3.5 laps between the two classes with good cars..not 6 laps..I wasn;t there obviously just curious?

Kevin,

The last trip to LINDSAY - 17.5 ran 76 (Steenhoven TQ and Hamilton A Main Win)

This trip 17.5 picked up 2 laps.

Last trip - Steenhoven ran Carlton's car WENT 72, Paul Cathey ran 71.

This time No Steenhoven run and No Paul Cathey...TQ was Bryan Blaser who picked up I believe 2 laps over his last trip to Lindsay.

Here's the July top runs.

McDermont Field House - Lindsay 07-27-2008 -- Car Driven by Steenhoven

Race# 1 -- 21.5 Stock - Heat #1 round 2 --
Pos Car Laps time name id
1 2 72 5:03.73 Carlton Duty * 1

McDermont Field House - Lindsay 07-27-2008 -- TQ

Race# 3 -- 21.5 Stock - Heat # 3 round 3 --
Pos Car Laps time name id
1 6 71 5:02.83 Paul Cathey 10


Best 17.5 Runs

McDermont Field House - Lindsay 07-27-2008 -- TQ

Race# 8 -- 17.5 Limited - Heat # 3 round 3 --
Pos Car Laps time name id
1 1 76 5:01.75 Erik Steenhoven 20


McDermont Field House - Lindsay 07-27-2008

Race# 6 -- 17.5 Limited - A Main --
Pos Car Laps time name id
1 2 76 5:01.09 Gary Hamilton 9

I'm gonna say the difference may just be the NEW GEN3 car... :)

gen 3 car worth 1.5 laps... highly unlikely,but if thats the case it should obsolet all other chassis's. So if steenie ran 21.5 he'd go 74 then. which makes more sense.
Hope to be there in NOv.

Joe,when are u changing battery\motor rules ?

Kevin,

Another part of the equation might be a pretty short practice session.

With us getting re-located to the Third Floor of a unfinished building...it took probably an extra hour to hour and a half to get things set up, and to not get even further behind on the day, I think the track was only open for practice about an hour and a half (or less) With 26 ENTRIES in the 21.5 ...it was very competitive.

IF I change any rules, they would not take effect until Next Season, and wouldn't be announced until LATE October / Early November at the earliest.

gen 3 car worth 1.5 laps... highly unlikely,but if thats the case it should obsolet all other chassis's. So if steenie ran 21.5 he'd go 74 then. which makes more sense.
Hope to be there in NOv.

Joe,when are u changing battery\motor rules ?

Koz - The GEN 3 is the most unbelievable car in the corner. It never seems to loose speed in the corner.:confused: I think the car is worth a lap. I got my rope ready for the next race so i can hitch a ride. LOL

seems like you guys have been running lipo for a while, are they better then nimh? are they worth changing over to? is it true you can run 1 battery all day and it will be the same at the end of the year as at the start?

seems like you guys have been running lipo for a while, are they better then nimh? are they worth changing over to? is it true you can run 1 battery all day and it will be the same at the end of the year as at the start?


We (Our SWTour Series) have been running LIPO Full Time in '08, and we ran it for testing and a few other events the end of '07, so our group has been on them for quite some time.

A group of racers up in the Flagstaff AZ area have been using them quite a bit longer than that (Over 2 years now I believe)

MOST of us only run ONE pack per car, per day. Myself, along with my Son run 3-4 classes on any given race day - so we actually had to start moving batteries around instead of being able to leave them in the car...just to be sure we don't get behind on the charging. Especially on a fast paced small local race.

LIPOs are NOT perfect, they are not the RACING GOD to Save all the EVILS of racing...however, if they are legal for racing where YOU race - they are very MUCH worth making the switch too (if you are in the need of new batteries)

If you have PERECTLY GOOD NiMh's, and are competitive or just happy with them...will you become happier w/ LIPO? Maybe....maybe not.

They DO:

Last Longer
Run Longer
Weigh Less
Run multiple times a day w/ NO performance Loss

But, they also

Require a Special LIPO charger ( plenty of chargers that can do LIPO, NIMH, and other cells)

can be dangerous if mis-treated (but so can NiMh's)

I don't know where battery technology will be in a few years, but for right now, LIPOs are probably The Coolest thing we've used in a Long Time.

in responce to the lap times, if you are running 3200 lipo against 4200nimh, I can see where you get the lap time drop off. The 3200 is pretty much spent at the end of a 5 min run. Even if you just use half of the mah, that still puts the battery on the backside of the charge. If you ran a battery like a 4000mah lipo, do you think the times would drop or would the higher c rating increase lap times. A motor will only use as much power as it is capable, so if a higher mah battery increases lap times, then I would say you are running the wrong batteries and "stressing" your 3200. I don't run carpet, just dirt oval.