13.5 LiPo
It is my opionion that after a guy has run a couple of years of stock or superstock, he should be ready for some light mod work and leave a space for some of the stock guys to place. For this reason I did an experiment on the flat asphalt oval. I took the same super stock 13.5 motor that we run on 4 cell and just upped the voltage with a 6 cell equivalent LiPo. I did this with my wide pan car. Gearing ended up only 1 pinion tooth less than 4 cell. Motor temps went up from 140 to 170F for an 8-10 minute run. Now were talking.
Here is the track experience. With LiPo, I now accelerate out of the turn on part throttle, I see the air dam lift a bit (cool). Acceleration is surprisingly fast when standing at track level, but just about right up in the 12 foot high drivers stand. I reach full throttle at mid straight and then start to slow for the corner. The throttle roll on and roll off are important to maintain smooth momentum. I corner with about 1/4 throttle. No slamming the throttle full at mid corner and holding it there until corner entry any more. A spec LiPo battery such as the new coming TrackPower 3600 with a hard case would be ideal. No more battery war, but still as much power as you need at any given time. No car setup change was need, little gearing change is needed.
If you bought a charger recently chances are it will charge a LiPo. One LiPo pack will easily outlast 4 NiMH packs and still be performing well on the track. The hazard is low with modern chargers and hardcase batteries that are roar approved. I have never bought a LIPO that did not exceed its label specs on capacity. 4 of seven of my NiMH's had to be returned due to deterioration of as much as 25% from just sitting for sale for a few months. That is close to industrial specs for a used up battery. Jeff has trouble getting these NiMH 4 cell packs for the shop. I have trouble finding them on the Web.
Charging at 1 C (3.6 amps for our spec battery) is desired for the best lifetime. It may even double the life over using 2C which can also be used.
John
Last edited by John Stranahan; 05-16-2008 at 06:03 PM.