13.5 Brushless v 12th Blinky

Had a bit of time on my hands as usual so had a look at the lap times from a national.

Picture is of first 19 laps from a recent national (Daves only do 5 minutes). Cars were driven by Dave Spashett & Richard Isherwood.

Wonder how close they'd be if both were 10.5 Blinky?

Figures on there own are the averages for the 19 laps.

[You must be registered and logged in to see this image.]

Those graph lines show sme pretty consistent laps (except where DS binned it on lap 5!). It just goes to show what good drivers with tallented thumbs can manage when they drive well setup cars.

We gave 10.5t/1s LiPo a (brief) try a while back in our 'Daves at WSMCC. This was in the days before the current circuit rules had been written and we were looking to see what went well and what might be good to replace 4-cell/G2 if and when it was needed. It was also in the days well before the GRP and Carbon CE chassis were around so we were all running the 'standard' alloy V12 chassis and mainly hotrod type bodies too.

Now, I'm not going to say, "been there, done that and it was rubbish" or, "1s LiPo / 13.5t is best" because things change - the new chassis (and other new option parts) offer very diffferent grip and handling characteristics, new speedos react differently, new shells have different aerodynamic properties and we all know a whole lot more about setting up brushless systems and cars than we did a few years back. So, if we try it again now we might well get very different results to what we got first time around.

What I will say though was that the 1s/10.5t combination in a Dave was fast. Very fast!

This can be both a good thing as well as a bad thing. Only the best drivers at our club could handle this sort of speed reliably and consistently which meant two things. Firstly, this gave us a natural split in the class (sort of equivalent to 'Pro / Mod' and 'Stock' classes). In some ways this was quite nice but, as club membership fell, it was also restrictive. Secondly, it meant a lot more crashes and a LOT more broken parts as some people tried to equip themselves beyond their own ability to drive, and their 'Daves beyond the capability of the chassis. This was not so good.

We also had electrical issues with the higher current draws these motors needed - we were taking a pretty hefty chunk of the 3000mAh or so capacity of the cells out each race, we needed more cells to see us through the night as there was now not sufficient time to charge between rounds, motors got silly hot and did not last too long, and there was still the same raft of problems with the low 1s LiPo voltages.

As it happens, most drivers ditched the 10.5t motors and went 'back' to 13.5t of their own, natural accord. And they actually went faster too - less power meant smoother driving, better lines, less crashes... All good! The best thing though was that racing had become very close again. Since the vast majority of drivers could handle this reduced power most of us were able to drive the 'Daves to their max. Now it meant that the person who won was the person who drove the best lines and drove the cleanest race, rather then the person who could just handle/survive the power. Now, as we see club membership on the rise again, we still see the same drivers at the top of the pile as we did when we tried other motors. The difference though is that the drivers seem to be enjoying the fun of close racing and smiling more than they did fighting the cars.

Let me stress that this was just a few drivers trying stuff, at one club, quite a while back. Our club is not set up for high speed cars of any variety - we run a relatively small area of 20x12m on a medium grip carpet. All classes that have attended the club over the years (Touring Cars, 1/10 Pan cars, Minis, 1/12 Circuit, 'Daves and even 1/18 class) have all suffered the same thing - too much power and speed causes too much cost and damage; reducing speeds and getting close racing allows more enjoyment.

Of course, there will be many drivers out there who love the speed, who want to bolt a 3s LiPo pack on and run a 4.5t motor and launch their 'Daves to the moon. If that is your wish then, please, don't let me stop you. I'll even provide a dustpan and brush so you can take all the bits home again :-)

Traditionally though, 'Daves have been seen as an 'entry level' class. Something that is quick and simple to build, something that needs only relatively basic electronics to be able to be raced, something that is usually cheaper than other classes to run too. This does not mean that the class is open to only beginners and advanced drivers are not allowed to race them. No. That is why we have the National Series! What it does mean though is that the cars are more basic than other classes. We use 1/4" mild steel for the rear axel. We have one of the the most basic front end systems of any class and almost no adjustment for suspension geometries. We run a very simple rear end geometry. We also run quite narrow tires and track widths. Thin tires, narrow tracks, basic suspensions and a high CoG do not lend themselves to fast cars, especially round corners....

Don't get me wrong, I love the simpicity of the 'Daves. Hell, that is why I have raced one for so many years and why I always go back to one after I have tried other classes. What I will say though is that I think the current speeds of 13.5t and 1s LiPo are about right. How you choose to achieve that speed (1s/13.5t or 4-cell brushed or 3-cell/13.5t or 2s/21.5t or whatever) is up to you but I really don't think that the chassis can handle much more. Sure, a faster sub-class for the 'Elite' drivers at National level might be fun, but for normal, club-level mortals I think the current speeds are about right.

Sorry for the ramble, just my thoughts.

J