Today, after a quick lunch with my friend Darko, I was restoring some old bitchar-g cars while he was testing some restored cars on the track after fixing the crono.
Those restored cars are very good so we lowered the track record, lapping it under 7 seconds; I was the first to lap it in 6”88 but Darko, in the evening, lowered it again to 6”74... amazing !!
Our previous record laps were a lot higher, ranging from 7”35 to 7”90....
The cars we were running are Shen Qi Wei, called “bullet clones” in the good old days; nowadays those cars have a common problem... internal batteries are broken and some batteries leaked acid too, corroding the battery contacts in the car.
Sometime the acid leak is a minor problem and you can fix it with a quick Dremel run, removing oxidation from metal contacts and polishing battery’s poles... but sometime acid literally destroyed the car’s metal contact and it is a major problem !!
In the past I tried to restore metal contacts with a solder job or using hot glue and similar methods but today I used a different approach.
It is hard to find micro batteries 1/3AAA with the correct height and diameter (15mm and 10mm respectively), locally I can find similar batteries but slightly bigger (18mm x 10mm), big enough to not fit in the bcg battery’s compartment.
A car with broken metal contacts and a too big to fit battery... not a pleasant situation !
After some head scratching I decided to mount the battery in a different position, moving it toward the front of the car and putting it just after the steering compartment.
So I soldered a couple of wire from battery to charging pads and from battery to bcg board so the electrical connections are restored; I cannot swap the battery without desoldering the whole stuff but who cares, I rarely changed batteries even it the old days...
The car has now a different weight distribution and, surprise, cornering ability is improved !!!
Improved even a bit too much, this little car now perform very sharp turns and cornering radius is decreased; it has an habit to spin out if you do not ease on the throttle when cornering...
A “jumpy” car with a good 2.6 motor is not easy to drive and it is not a fast car on my track so after a dozen laps in the high 10” a pit stop was needed !!
In the pit I mounted hard tyres on the back wheels and started to tame the beast.... lap after lap the car was a solid runner and, thanks to the discharging battery, was easier to drive (I charge batteries with an external charger so we have almost 20/30 minutes of running).
The final result was a stunning 6”71 lap, new track record !! ;) and, last but not least, I can use that easy to find batteries to restore broken bcg with corroded metal contacts and transform them in sharp turner !!
I’ll take some picture to show what I have done, those batteries are used in cordless telephone so every consumer electronic store should stock them.
Another experiment will be to mount a battery along car’s middle line and, maybe, moving it forward or backward you can change car’s turning and accelerating behaviour... like you do with ballast in real racing touring cars !
Stay tuned, maybe I’ll experiment this solution this evening !!
