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Old 07-10-2006, 10:09 PM   #61
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Quote:
Originally Posted by tallyrc
sounds like no matter what the rules, the sponsored guys are going to find a way to push the envelope and stress whatever equipment is in the car anyhow... so why change it so the top .25% don't over heat their car in the mains? sounds like that is part of setting up the car is to make it so it lasts 5 measley minutes.... in every form of racing you can find ways of going faster if finishing the race didn't matter....
if the top 0.25% are having trouble getting it right, how do you think the bottom 99.75% is doing?

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Originally Posted by tallyrc
maybe spec tires with limited traction is the answer.. that is what keeps offroad sane.. the fact that more hp is a detriment...
more hp is a detriment - that's the whole reason about this discussion
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Old 07-10-2006, 10:15 PM   #62
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I've got a new rule...

"Don't be stupid"

This simple rule will stop most of the arguements in threads like this
This simple rule will keep people from gearing their stuff to the moon and overheating stuff...
This simple rule will not be followed or understood by anyone who is "stupid."
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Old 07-10-2006, 10:22 PM   #63
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Originally Posted by stulec52
Maybe we have to find the reasons why most regular racers find mod (especially open mod) so difflcult to run week in week out?
It really can't be just money can it? Back in the early to mid 90's stuff cost pretty much the same amount as it does now, and I like to think that most of you out there earn a little more today than you did back then ! Great topic !!
back then parts were a little thicker. things took longer to wear out, because i wasn't using the same high powered cells or motors as we are now, i wasn't going as fast, overall my money went a little further and not everything was cf or alum.

cars of today are not really comparable to cars of yesterday. and thats why the rules change in any class.
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Old 07-10-2006, 10:45 PM   #64
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You know if things are getting hot you could just allow for a little air-intake in the bodies and I'm sure that would do wonders to help keep things running cooler.

How well would nitro sedans run if they were not allowed to run holes in the body for airflow?

I'm not saying cut out entire windows or anything... but... maybe the grill could be allowed to be opened or something
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Old 07-10-2006, 11:09 PM   #65
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Quote:
Originally Posted by Evicerator
You know if things are getting hot you could just allow for a little air-intake in the bodies and I'm sure that would do wonders to help keep things running cooler.

How well would nitro sedans run if they were not allowed to run holes in the body for airflow?

I'm not saying cut out entire windows or anything... but... maybe the grill could be allowed to be opened or something
An Idea that makes sense.
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Old 07-11-2006, 02:06 AM   #66
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Originally Posted by speedxl
Also since it seems all the electronics seem to be failing or overheating then its time the electronics manufactures raise their products performance levels.
I agree. As I said it's possible for ESC manufacturers to 'up' the performance levels, at MRT we have already. Some manufacturers appear to have taken their focus off brushed and are now pushing their new brushless systems the result is their brushed ESC designs are now behind the performance levels required for the latest high performance cells and the result is overheating speedos. The way to have speed controllers run cooler and not to overheat is to have a design with enough MOSFETs to handle the power. If your ESC gets too hot due to lacking MOSFETs the answer is to cut holes in your car body to make an air-intake, extra cooling is certainly useful but not always a practical option!

It's no wonder action has been called for, when cars cut out and stop due to overheating speedos during a worlds race or final with everyone watching it's bad for the team and the manufacturers. Because brushless is still new and developing there will inevitably be more failures but for brushed the ESC technology and designs should not have overheating problems.

If there was a move to running 4 cells it would then cause more receiver and transponder problems due to the lower operating voltages.. something to consider maybe?
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Old 07-11-2006, 02:08 AM   #67
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I'm afraid I have to agree with most of Derek B's line of thought. I am totally against any form of mechanically or technically slowing cars down deliberately. I repeat, there were plenty of guys at the Worlds capable of handling them, and remember the TC Worlds is our Formula 1, our World championships, our absolute TOPS.

Cars sell on how fast they are, and nothing else. You try and persuade a kid that he should take a car that's 5mph slower because it is more reliable. Forget it. For that matter, you try and persuade a grown up, intelligent, man.

Why do you think Formula 1 today is so dull. Because Max, Bernie, and their close buddies keep fiddling with the rules. Formula 1 was best when they had engines developing over 1000 bhp from 1.5 litre. Never mind the fact that they broke down more. That was an accepted fact - a trade off, if you like.

I do have an idea for our RC cars however, which would be a bit of a compromise. Increase the weight limit from 1500 grams to 1600 or even 1700. But don't touch or restrict anything else. Now nobody will skimp with material and there will be less breakages - and presumably everybody will be happy. Some hope
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Old 07-11-2006, 04:09 AM   #68
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f1 is 'dull' because the wrong changes have been made. reducing mechanical grip instead of adding drag etc. if no changes at all were made f1 wouldn't have survived this long and many more lives would have been lost along the way.

that's hardly worth arguing here... i can't see the relavance to this discussion.


modified is becoming too elitist mostly due to the ever increasing costs (dead esc's, motors burning, etc).

if everyone race these things for the speed, why then is it that stock is by far the largest class?

regarding stock it also seems that it's becoming much harder for stock drivers to progress to modified.

cost/maintenance benifits aside...i personally would rather race a bit slower car in a bigger field of mod than be flying around at uber speeds in a small field of drivers.

the rules we were race under were written when what... cells were under 1.10v when discharged at 15 amps. so best case ~1.04v per cell at 35 amps - 6.24v across the pack.
with top packs now you're upto 7.4v packs and that's using the numbers from the average discharge.
this is before you consider the fact we literally have runtime to burn and as cells progress it can only get worse.

i cant see how current motors running on 4 cells could be made to destroy themselfs like motors are currently with 6 cells while still performing on the track for 5 minutes.
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Old 07-11-2006, 04:11 AM   #69
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Lets face it if TC mod is the Formula 1, then why should it reflect much on the similarity of the other 90% of racers. After all, how many people who race full size cars go out to the local speed shop and buy a Formula 1 car. This is a business about making model cars that sell.

People are trashing cars that they saw a top driver win a large race, beause in the car is too had to maintain or parts are not available. If you go to your local track which is not of th caliber of a worlds track and you can not keep the car running, it becomes a poor excuse for a paper weight.

Why are the fuel cars not having this problem? The ranks of off road gas seem to be growing.
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Old 07-11-2006, 04:15 AM   #70
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Quote:
Originally Posted by volracer
Why are the fuel cars not having this problem? The ranks of off road gas seem to be growing.
because they control how much power the motors generate, less % of nitro etc.

their fuel hasnt doubled in power in 5 years has it?
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Old 07-11-2006, 04:31 AM   #71
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Quote:
Originally Posted by tones
the rules we were race under were written when what... cells were under 1.10v when discharged at 15 amps. so best case ~1.04v per cell at 35 amps - 6.24v across the pack.
with top packs now you're upto 7.4v packs and that's using the numbers from the average discharge.
this is before you consider the fact we literally have runtime to burn and as cells progress it can only get worse.

i cant see how current motors running on 4 cells could be made to destroy themselfs like motors are currently with 6 cells while still performing on the track for 5 minutes.
tones has some very good points...

current brushed motors are based on technology that is 10-20 years old, batteries have doubled in terms of power, but motors have only improved what... 10% maybe?

although brushless appears to be the "future" of rc, at present it's simply not working, people are destroying speed controllers, and having to replace rotors as often as i throw winds.

last weekend i raced at a 'regional' event in australia, we had 16 people in mod, and 2 speed controllers died from it. 2 weeks before that i was at a 'national' event, with around 30 drivers in mod, and at least 3 speedys died, with countless brushless motors thermalling in the A mains, from people just trying to keep up with each other. i also killed 2 brushed armatures at this event.

simply put, 7.4v is too much power for the current generation of motors, either the motors need to improve dramatically, or we need to limit the power we force into them.

don't get me wrong here, i love the speed and pace of modified, but the only thing better than the speed is the competition, the thrill of racing an inch from somone else at high speeds...
4 and 5 cell TC isn't _that_ much slower, with the lower weight and better balanced chassis, our laptimes will be very close to what they were with 6 cells, there's a lot of people saying that 4 cell will lead to 4 turn motors, and more strain on other equipment in the car, when they've never tested anything themselves, or even seen it first hand being tested.

these people just sit on here, uninformed, whinging about losing a tiny bit of speed, and scarily enough (please dont hate me for what i'm about to say) they seem to come mostly from america, the land of cars which are dynamite in a straight line, but cant take a corner to save themselves. 4 cells can mean a drop in weight to 1300gm, which means higher corner speeds, and also means that the motors dont have to work as hard (so higher acceleration/top speed compared to 1500gm @ 4.8v), which brings it back to very similar speeds to a 6 cell touring car.

for those of you who dont beleive me, next weekend before racing, drop in 5 cells instead of 6, gear up a tooth or two, and see for yourselves.

kudos to japan, for having the balls to actually try 8 minutes, and 4 cells. if the rest of the world's governing bodies were like the JRMCA, maybe we woudln't be at this stage right now.
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Old 07-11-2006, 04:35 AM   #72
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Just to get it correct:

Japan (JMRCA) had 6 cells and 8mins for the last 2 years and changed to 4 cells and 5mins for this year. No racing under these new rules has been taking place in Japan yet.
According to japanese motor builders and manufacturers the strain on the equipment (motors, speedos, drivetrain, tyres) is much less when they did testing with 4 cells.

Also there was no decisions been made at all, the manufacturers are sent home to do their own testing and give their input to IFMAR.
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Old 07-11-2006, 04:59 AM   #73
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Quote:
Originally Posted by burito
Just to get it correct:

Japan (JMRCA) had 6 cells and 8mins for the last 2 years and changed to 4 cells and 5mins for this year. No racing under these new rules has been taking place in Japan yet.
According to japanese motor builders and manufacturers the strain on the equipment (motors, speedos, drivetrain, tyres) is much less when they did testing with 4 cells.

Also there was no decisions been made at all, the manufacturers are sent home to do their own testing and give their input to IFMAR.
Thanks for shedding some light on the situation
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Old 07-11-2006, 05:29 AM   #74
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Quote:
Originally Posted by johnbull
I repeat, there were plenty of guys at the Worlds capable of handling them,
It's not a problem of handling that speed, it's a problem of being able to afford that kind of speed.

Don't forget that IFMAR/EFRA/ROAR/FEMCA/Etc. rules trickle down to the local club drivers. Good rules at the top level will ensure good racing on a club level. Which in the end will support top level racing.
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Old 07-11-2006, 05:54 AM   #75
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Quote:
Originally Posted by Jaybo
simply put, 7.4v is too much power for the current generation of motors, either the motors need to improve dramatically, or we need to limit the power we force into them.
I said the exact same thing more than 6 months ago on a similar thread... no one seems to get it

There is a distinct shortfall in motor advancement when compared to battery advancement - better cells are being produced far quicker than better motors.

This is even apparent with brushless technology where the motors are ok but the esc's then become the weak point in the chain.

Part of this is due to various motor rules - which restrict brushed motors to 20+ year old technoology whilst allowing cell manufacturers to have every latest-and-greatest cell type approved.

You have to ask yourself who is driving the sport, the governing bodies or the cell manufacturers?

We ourselves are also partly to blame because it is the racer who always wants the newest, fastest, biggest capacity cells, and it is the racer who buys these before they are legal, then go on about how great they are, and then pressure our governing bodies to legalise them asap, without thought of long-term consequences.

We have a few alternatives:

a) drastically increase motor technology to be able to handle the voltage/capacity of current cells (and hope the esc manufacturers can also keep up)

b) slow down / limit cell technology and/or frequency of release.

Option A doesn't look like become a reality anytime soon, especially without our current motor rules being re-written.

Option B is even less likely, given that our hobby is consumer driven and we always want the latest-and-greatest.

So that currently leaves the 4 or 5 cells option as the only current "possible" fix - though whether this will work in the long-term is debatable.
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