Originally Posted by
SSTAT
First time posting here, I'll share a little story. Hope you dont mind, this is the Vintage section after all. I used to race an Ultima in indoor carpet racing here in eastern Ohio back in the mid 80s. my friends had cars but none were into it like I was, so my dad took me to a track and that was it. I remember my first race the car quit after the first race and my dad and I had no idea what was wrong, we asked a fellow racer and he asked us what the brushes looked like and we said "whats a brush?" Anyway after a few years and decent success I sold the car to by a real car. I actually do road racing in a camaro now. Anyway my parents sent over my old tool box I took to races and I was amazed at what was in there. I have some pics attached (I hope). There the rotating turn table stand my dad made for me, an old Kyosho race box, a cooling fan for the batteries and charger between rounds. Dig the 'World champ' medallion on the radio and the Kyosho supersport motor. Apparently I took out all the electronics when I sold it. Everything is there, including the charger. The LCD didnt work when I plugged it in but it turns out the LCD is powered by a 9 volt inside! I replaced it and the thing works! So what the hell I plugged in the Kyosho NiCD and the thing is taking a charge! I set it to trickle only and its at 8 volts. I unplugged it and it drops about .01 volts every 5 seconds or so. I cant believe it! Its about 32 years old! I mean I dont believe its going to work well, or for long but still! So the night after I found all this stuff I get on ebay and theres a first gen ultima (3115), exact same as mine (when it was new, of course mine eventually had a full race body on it etc), complete except for the electronics. It was like destiny! So I bought it and here we are. So anyway, I have some questions.
1. One thing Im missing is the pinion gear. Ive determined that the shaft of the motor appears to be the 3mm variety rather than what looks like the current standard of 5mm, correct? I can find one source that says the original tooth count from factory was 15, and another source that says the pitch was 32. Can anyone confirm any of this?
2. Given I think Im going to need a new battery, I need some advice. I dont need it to be any faster than stock, I just want my old parts to work and not get fried, but I wouldnt mind if it lasted a little longer that the stock 1200mah. I see I can get a 7.2 volt Lipo, but Id have to get a tamiya adapter and Im afraid it would fry my motor or ESC or gears, or is lipo a possibility? It looks like NiCD is no longer in use. which leaves Nimh. If its a 7.2 volt battery, can I get any mah as long as it fits in the chassis? Or is there another measurement I need to know to see if it works with my speed controller and wont melt my gears?
Thanks for any advice!
Hi, Not sure about the pinion gear but re batteries.
Depending on what esc you have, and what motor, you should be fine with any 2S, 7.4v Lipo. Main thing will be to get one that fits. There are some that resemble the shape of a Nimh stick pack. You can probably find a Nimh stick pack (6 cells) if you want but the Lipos (hardcase) are fine with correct charger and usage. And they are lighter and will run longer and stronger.
Here is Sydney, Australia we have a few vintage events (including 5 hour enduro where you get 20-30 minutes constant run time of racing) and run Mabuchi/ Tamiya silver can motors, or Tamiya Sport Tuned 23t motors with Lipos all the time.The Ultima's transmission should be ok as long as you don't have too low a turn motor (you still have brushed motor?). Gearing etc should be set for keeping under approp motor temps. Which depends on run time and usage.
What esc you have/ planning to run? There are some inexpensive new brushed motor esc out here that are made for Lipo use as they have lipo low voltage cut offs. But you can also get a low voltage warning audible buzzer (common with aircraft use) that would do similar if you set the warning correct. We use these in the enduro racing to avoid hitting the lipo low voltage cut out and hence avoid the crawl/ safety mode (it might be vintage and silver cans but we are trying to go as fast as we can for the whole run time).
I have a Novak GT7 esc and it goes fine with Lipo (2S, 7.4v, 4000).
Interested to know how you go as am looking at 2 vintage Ultimas to turn into vintage racer here.
Cheers, Thommo