CraigM

iTrader: (34)

Not being a douche, but why would 25.5 with timing be a recipe for burning motors compared to anything else, like 21.5s with non-timing?

I agree the spec system is the only way to control esc timing, if that's what people want to do, but I think picking a single brand for stock (that's what we're talking about here) takes something away from racing. People keep quoting mini as case study but mini is coming from a spec motor to another spec motor, I question whether that would work for non-specced class.

RacerEd

iTrader: (2)

Sorry guys, had to respond to this as it's just not good theory.

This also does not take into account all the numbers that actually mean something! The rating off a FET in a ESC can not dictate what current the motor gets. This totally ignores the internal resistance of the batteries and hence what they can supply along with the resistance of the motor and what it can draw. Under this theory a ESC with boost would not go any faster as the current is already maxed!


Yes the way the motor is built is directly related to what it can draw under load! If you have two pieces of the same material wire different lengths then the shorter will have less losses and be able to draw a higher current in a closed circuit, same for a thicker wire.


Again this now ignores the increased resistance of a longer winding vs a shorter one and the current it can then draw and the field strength it can then induce. I don't know if I should laugh or cry...

mangoman

iTrader: (11)

From a sydney perspective that may be true, but almost all our racing is done on smaller dedicated electric tracks.
I would assume for clubs with bigger tracks (ie those truely shared with nitros) the difference between 10.5 and mod is more marked.

However, this does not take into account the fact that a 10.5 and mod cars should drive entirely different. Where a 10.5 will probably be more smoother through a corner the mod car has raw power. It means that cars are driving completely different speeds in all parts of the track which would make racing quite painful.

I also dont agree with slowing 10.5s to to 13.5. To me 10.5 should theoretically be a stepping stone to mod. The fact that 10.5 is often faster rarely is the result of the motor being more suitable to the track, but rather is the result of a driver not being able to handle a mod motor.
Also why slow the class because of the inability of some drivers. If you cant handle the speed of a mod, and think the 10.5 is too fast.... for some reason i think you may be running the wrong class.

Dragonfire

iTrader: (1)

Hey racer ed...

I don't think a single person believed a word he said anyway... Not unless our ESC ratings mean nothing all kf a sudden... It was very amusing to read though...

gameover

Lets not lose track of the on-road issues guys.

1. Everyone agrees that the old non-timing 17.5, 10.5, mod class speed are the ballpark (approx the old 27t & 19t speeds). Right now everything is squeezed up against mod.

2. teching speedies really is a joke (unless they are one brand spec, non flashable etc.). The rules need to be implemented down to club level not one set of rules for clubs and another for nats. This will drive people away from on-road.

Personally i liked the original ROAR plan until they announced their silly flashing lights teching plans.

17.5 spec ESC (stock)
17.5 open ESC (super stock)
mod

although i do agree that if we can get a 25.5 open ESC running similar speeds as 17.5 spec ESC it removes the problem of teching any speedies (yay!) and crazy pinion/spur combo's. I'm not sure who makes 25.5 motors apart from Novak but i'm sure others exist.

I'm also interested in the HW spec thing as a 540 pro equivalent (for club & state level). This is a large class that is slowing due to drivers not seeing a way forward to brushless. Many are going to stock and losing interest becuase the skill jump is just way too big.

anyway, my 2c

Chris...

NOFX

iTrader: (25)

im really enjoying this thread, theres a lot of good ideas being thrown around, potential solutions, a lot of people loving the classes the way they are at the moment as theyve grown used to the speed and now find it very enjoyable.

just looking at all the theories in here, im starting to think that a mix of things could be a solution (again im mainly thinking off road) but if we're looking for a stock class slower than 17.5, and 21.5 is thought to be not "slower" enough, maybe the combo of 21.5 and Life packs could be the answer plus a cut-off list of speedies and then every 6 or 12 months new speedies are added to the allowed list, just to help prevent the jumping ship every time a new "super" speedy comes out, there is still potential in the esc programming for a bit more speed to come, but if we slow down when new speedies are allowed to be used for sanctioned events, it will help the cost factor (this is the simlar principle that AARCMCC has applied to the approval of batteries in the past) not much we can do about the firmware upgrades, but they are issued free by the manufacturers anyway so its an area that should be left open.

So the principle would be pretty simple, at 31/12/10 there is a cut-off called and all speedies released after that date are not legal until july that year or january the following year. Life batteries must be used and if we still need to accomodate nimh racers, 5 cell nimh could be allowed too and 21.5 motors

Maybe someone can offer some more info about Life batts, lipos are rated at 7.4v but peak at 8.4v and put out around 8.0v for a lot of their charge. Life is rated at 6.6v, so we're looking at a significant difference of about 1.0v which depending on how u look at is is 10-15% less voltage, which would affect both acceleration and top speed. people might be annoyed at having to buy a new charger and battery, but i'd say most people would buy a new battery every 6 months to a year anyway, and most current chargers can charge life packs anyway and there are lots of good cheap chargers around.

I guess the other consideration is if we go 21.5 or 25.5 etc, we are going against what other bigger countries are doing, which isnt the end of the world, we can do what suits us, but whether there will be motors for us to use as we go on is something we'll need to think about, i think 21.5 is ok, as there are a fair few manufacturers producing them already

ant0276

iTrader: (2)

Why are all the solutions based around having to buy new gear?

I tried the lead thing I suggested a couple of pages back and it was easy. Did it with a hand held two channel CRO I have (nothing special-real rugged field worker machine) and it was no more complex than Dynoing a 540. The 540 dyno provisions have been in the rules forever, and no one has a problem with them.

If you are responsible for corect timing, i.e. motor + speedie=timing and you decide to bend the rules, you get disqualified.

There was an incident in vic early this year (a non legal motor won an event - no deliberate cheating is implied, it was a genuine "didn't check" error) and the result didn't stand as the driver was disqualified. I should also point out that the disqualification was taken in a very sportsman like manner from what I've been told.

If you can program your esc, you can check it (even if you have to ask the manufacturer what timing setting "number 15" is), and if an RC racer can't add up two number two make 24, I think it's pretty safe to say that they can't set up their car either, with all those numbers for caster/camber/toe being oh so complex and all

Anyway, my point is, it is the driver's responsibility to conform to the rules, and checking it is easy, as racers we just need to have the tenacity to say Here's the equipment, it lives with the scales and the chutes, and here's how you use it.

I find it hard to beleive that even struggling clubs can't find $100 for the machine, there is a 2ch one on ebay at $45 with one day to go right now......

my 2c for now, and back to silver can racing for me (until it's obsolete and I have to buy that RS pro, of course) At least I'm getting lots of wheel time with my vintage cars

waOscar

Here is a crazy thought for everyone to consider.
The only reason the current crop of speedies work is because of the capacity of the batteries we have to draw the power from.

Why not limit the maximum battery capacity to say 3000mah.

This will slow down stock in order to make run time.
Very easy to scutinise.

old_skoolie

iTrader: (7)

Not really,
I go very fast with an old set of Harris 3200 20C and only use 1600mAh
good to see people thinking outside of the square,

why not have
variable timming ESC with 25.5
and
permanantly non variable timming ESC with 17.5
as stock

reckon those 2 systems would be close to each other
that way it would be cheap for the beginner, cheap esc and 17.5 and it'll allow racers with the new breed of ESC to play with timming boost etc andsc rutinneering would be no harder to do, just a list of ESC incapable of timming advance

gameover

lipo's don't like being run flat, they get ugly.

here's a crazier idea for you, but would be sooooo cool

An interesting idea along these lines to enforce power limits is a cheap, standardized, wireless, battery interface unit. It includes a current limiter, mAh meter and a fixed low voltage cutoff. It is color coded to each class and the mAh consumption meter is preset to the class of racing. Once your allowed amount of mAh has been used it switches to current limiter (go slow, half power, oh crap i still have one lap to go) mode.

At the start of each race the timing software "zero's" each battery unit, or in a cheaper scenario picking it up off a rack it is zeroed.

You can run as much battery as you want, organisers can enforce any limit they want, no lipo dangers. Basically its a virtual fuel tank, in the extreme you could even enforce "recharging" pitstops or heaven forbid actually have longer races... lol! There are a lot of different things you could do to safely spice up racing with such a simple device.

It can just be a simple RFID based thing that talks to the timing software every lap, displaying how much "fuel" each driver has left. Wouldn't that be cool to watch?

okay so there's the basic idea, someone develop it, write a standard into the rules, get it made in china for $50 each (send me a cut), clubs buy a couple of sets or people can buy their own and off we go!

BAM Motorsports

hay dragon do you ever read the specs of an esc fully or just the continuse current

here's the spec of an esc
1 Specification


1.1 Output: Continuous current 120A, burst current 760A.
1.2 Input: 4-9 cells NiMH/NiCd or 2-3 cells LiPo. Note1
1.3 BEC Output: 5.75V@3A linear mode built-in BEC.
1.4 Resistance: 0.0003 Ohm.

heres a link to check the detales

other esc's have higher burst current

jay m

iTrader: (16)

isnt that burst 760 max i thought you were talking thousands of amps sorry still dont understand are you saying it can draw more amps than its burst amps is rated at

BAM Motorsports

the specs i put up is a standed esc drawing higher then the bursts amps usually fries the esc there is esc's out there with higher burst amps out there alowing for the motor to pull higher amps before frying something

Loc'tar orgar

i'm in agreeance with bam here we should be running inside the rules could be a good start to slow the cars down no rule changes needed just drivers buying the wrong stuff to go racing has caused this one

cannon

iTrader: (35)

So the new ESC's have nothing to do with the speed of cars now? Just the lipos?

And I notice a single post? Wonder who this is