303slowdown

iTrader: (24)

This is a thread about motors not weight.

djgrom

iTrader: (1)

I definitely was, but I figured I would let the discussion happen since it was way more informative then my original question would have allowed for.

djgrom

iTrader: (1)

The short answer is yes. I used to race motorcycles and for every pound of rotational weight we could remove it was roughly like the bike dropped five pounds.

Aaron P

iTrader: (3)

If I remember correctly, every gram of rotating mass is worth 3 grams static.

scirocco14

iTrader: (5)

And every impact with the wall is worth 100g.

djgrom

iTrader: (1)

So since we all agree that the D4 motor meets ROAR specs but is not ROAR approved has anyone used the 24K, I am looking at the motiv as well but not sure how it compares directly to the NOVAK boss.

scirocco14

iTrader: (5)

I'm running the Novak Boss and the Motiv 25.5 in my USVTA cars (I have two...one is primarily a loaner). I've won A-mains locally with both motors, and beaten and have been beaten by the 24K.

The motors are all so close you'll be fine with any of them. Each has to be geared slightly differently to make it work optimally.

Mark

djgrom

iTrader: (1)

How do you gear the boss motor? I keep playing around with the gearing and get pretty close but think I miss the sweet spot.

scirocco14

iTrader: (5)

Depends on your track, motor timing, etc.

Interesting experiment. My friend was messing around with gearing on his Novak and started at 3.8FDR on our medium sized track. He kept going down on the pinion, one tooth at a time. From 3.8 to 4.5 FDR, the lap times did not change signficantly. In fact, he got a little faster at first and then it wasn't until he went over 4.5 that the lap times started to drop off a little. Motor temps dropped quite a bit though.

So that just shows there's a pretty wide window for gearing.

Mark

djgrom

iTrader: (1)

I have the motor timing set all he way up to the end mark but not past. I think now you are allowed to advanced it more I would have to check. We set up a track in the parking lot every weekend, I would have to measure it but I think it is 50x120 how we do it. Generally have more turns then straights. So far I have tended to gear the motor more on the torque side so I can get to max speed quicker even if it is slower between turns but I am not sure if that really is the best, just my theory.

scirocco14

iTrader: (5)

Only thing that matters is lap time. So don't worry about if your car is faster/slower on straights than others. Adjust gearing and/or timing and look at your top 5 or top 10 average.

Mark

djgrom

iTrader: (1)

Wow I totally wrote that wrong. I have it geared for more torque so I can get to top speed between turns faster between each turn even though I sacrifice top speed it seems to suit our tracks better.

bertrandsv87

iTrader: (2)

Good to know that the novak is close to all the other motors.
Mass/ rotational mass will be critical in VTA since everybody builds their own tires: lighter foams might account for over 10gram less per tire or more in addition to the lighter drivetrain... That might make it seem like one motor is way faster than another with the same gearing.... Yeah I know this is a motor thread, but motors don't make any contact with the ground...

DARKSIDE

iTrader: (2)

USVTA rules state you must use stock foams that come with the HPI tires.

djgrom

iTrader: (1)

I think I am going to get another thread going to talk about VTA performance tips and discussion. I don't mind just using this thread though. It has been way more informative then I thought it would be. Where do you get lighter foam for the tires? I haven't thought about it but I have a little scale I should weigh the wheels I use and see if there is a better option.