DrGoatboy 132 Posted May 6, 2020 After years of having a lunchbox I have recently purchased a lovely vintage manta ray. I've put modern ESC and radio gear in it and all is going well. I am using the same NiMH battery packs I used in my lunchbox (which runs a sports tuned) and the batteries last at least 30mins in the lunchbox but only about 15mins in the manta ray. Now I guess the manta is a a smidge heavier, and has the extra battery draw of 4wd but I wasn't expecting that much difference. Is that normal? Maybe my battery pack is dieing and it's just a coincidence. Never had 4wd tamiya before so I don't know what to expect. Share this post Link to post Share on other sites
TurnipJF 9113 Posted May 6, 2020 That is perfectly normal comparing these two vehicles. The Lunchbox has a very simple and efficient drivetrain with few parts and low rotating mass, geared low, driving a simple and light chassis. The Manta Ray is heavier overall, with more parts that rotate giving more friction in the drivetrain. You don't mention whether it has been ballraced - being vintage it may not be as bearings cost a fortune back in the day. Even if it has been, it would still have more drivetrain friction than a Lunchbox. Also, being a wider, lower chassis capable of handling far higher speeds than a Lunchbox, it is typically geared for speed, which draws more current, again impacting on runtime. 1 Share this post Link to post Share on other sites
DrGoatboy 132 Posted May 6, 2020 Thanks turnip. What a great explanation! Makes perfect sense. Looks like it's Lipo time!!! Share this post Link to post Share on other sites