McSmooth

Even EASIER!

Danny/SMC

iTrader: (2)

John Bull: So far what we found out is that the IB3800s require a different motor setup than the GP cells. Next time your at the track measure the temp of your motors after the run and you should see a higher temperature with the IBs. You can either use a higher turn or drop the timing on the same motor when using IBs.

the_barbarian

iTrader: (3)

ive noticed the difference between the novak gt7 not going soft with IB3800's compared to the Q2 on setting 5

now im wondering if reducing the punch level on the Q2 is going to help or is it just going to make the car slower therefor no punch loss but no mega IB punch to begin with ?

stefan

"Shucks, I guess we Americans are just plain dumb. Oh well, maybe some day we will wise up. ."

"After this particular posting, I wouldn't get my hopes up too much, at least not for yourselves, Mr.Jaco!"

Is that better? Can you be rightfully insulted now?

I sure hope so!

McSmooth

Thanks for clearing that up.

Jack Rimer

Thanks, Stefan, for writing it larger and in colors. That makes it much easier to understand.

stefan

Don't mention it!

teamgp

With stock motors, I've found that reducing the amp draw by either of the following two ways kept the voltage high and the motor temps low. I was able to gear up a tooth for more top speed without losing punch in the corners.

1. Use a 1.5mm drill bit with a slow speed drill and light pressure to drill a hole directly in the center of both brushes. You have to be carefull to put the hole directly in the center and not allow the bit to touch and scratch any other part of the brush surface. If you use too much pressure or speed, the brush may break apart as well. Go to stiffer springs on the positive and negative as well. I prefer to use the Reedy 769's when available. They are the same compound as the 767's, but have a hole pre-drilled perfectly.

2. Another modification you can use by itself, or in conjunction with drilling, is use a file to shave .25mm of the sharp edges off both lips of the brush surface.

I used both of these successfully this past race weekend. Taking out the first (very short lap time) and second (let the pole setter pass me) lap times, my average lap time in the first half (13 of 15) was 10.444. Taking out the 24th (made a mistake) lap, my average lap time in the second half was 10.433.

If you split it into thirds and take away the first four laps of peak voltage and the 24th lap for the mistake, here are the average lap times:

Laps 5-12: 10.423
Laps 13-20: 10.324
Laps 21-29: 10.518 (10.472 if you also take away the 25th lap)

Keep in mind that the mistake on the 24th lap carried over into the 25th lap as I had to slow up and let the race leader lap me. It cost me about 4 tenths in the 25th lap. The fastest lap was a 10.174 on lap 17 and the last lap time was 10.320.

I stored the IB3800 pack after discharging it to .9v/cell earlier in the week after testing and then trayed it overnight Friday on an Integy zero tray. I took it straight off the tray and used the step charge info below before each run. After the qualifiers, I only had time to discharge it with a 30A light tree and let it cool to below 85F on a fan before step charging again. I didn't use the tray on race day at all.

8A until 3050mAh
.2A until 3080mAh
6.5A until 3500mAh and waited until 5 to 10 minutes before the next run
7A until peak of 15mV/pack

The pack came off the charger around 140F(60C) each time with only a hint of venting seconds before the peak and no other problems noticeable.

dodgeguy

iTrader: (208)

Great info. But 140 seems a little hot for the IB. Danny is saying 120 or so.

teamgp

Yep.

I plan on continuing with this method and I'll be monitoring their performance and lifetime pretty closely.

You can reduce the finishing temp to around 120F by changing both the 3rd and 4th steps to 6.0A.

Danny/SMC

iTrader: (2)

140 degrees on a temp gun is actually the right temp range you want your packs to peak at.

Danny/SMC

iTrader: (2)

Stefan: I thought internet connections were not working in Germany. After the great results the IBs had in Vegas we haven't heard from Marcus. Guess the super low GP cells are only available to the superior Europeans.

JohnMatrix

more of a general question:

With three step chargers keeping the temps down and the much more cooling jig doing the same thing to prolong battery use, do lower temps hurt the preformance?

Nice hot pack before a race is a good thing right? not to hot to handle but warmer than the three steps let it get and the jig.

Thanks,

Nick

teamgp

On race day, the packs peak at about 140F. But when I've cycled them at home with the Futaba CDR-5000, the temps jump up to 170-180F soon after the 30A discharge starts and finish just as hot. The discharge results show a great strong and long run with good IR numbers though.

Take this for what its worth. From what I've seen in the past six weeks of hardcore weekly cycling/racing, I personally believe the materials within these cells can take the heat without any problems. This is why I've decided to continue to work 'em very hard this fall. As a matter of fact I've also noticed that with each days use, the individual cells within each pack are reaching .9v closer together, as seen on the Integy tray, and now all six lights are pretty much uniform in going out.

However, since past generation cells have not produced good on track results with post charge temps above 140F, I think most drivers are applying the same paradigm's to the new cells. Only time will tell if they fit the same mold or not.

Mr. Blonde

@Danny
Who won both TC Mod classes?? GP or IB??

Just joking Danny, but thats they way how it was.....
We made some more tests with IB/Vtech and for 12scale they
feel better than GP's, specially on runtime. I guess Blacky was
using IB's in 12scale, did he??

We still disagree with TC, seems the cell can not handle high amp draws
in our tests..
Anyway, future will tell whats best and sure, its fine to see two battery
companys that offer good cells.
Have fun guys,
Markus