would it be hard to have the motor end bell up ?. and try to work some neat transmission round it. would it have any set backs ?

Just think about this for a minute

You have the motor in the car endbell up - you are jumping the car and the motor is spinning - what happens ?

email your answer to [email protected]

:o its true i am an idoit

You are not an idiot at all.

If people didn't come up with new ideas then we would be stuck racing the same boring old things wouldn't we :)

Would be an interesting gearbox mind ;)

If you have the motor end bell up think about the weight distribution, and the high C of G. Innovative idea still.

I am thinking, only thinking mind, of making the wishbones part of the aerodynamics, as in they generate downforce, so that the wing can be a little more refined;)

Oh dear, this might not go down so well but bear with me…

Aerodynamics, down force, on a scale buggy doesn’t really exist. Ok now before you throw your chair at me, let me explain a bit.

Yes I know, body shells and wings make the cars handle differently, and that’s a fact but it happens because of the drag being produced not because of downforce. Why not? Well because air density increases with speed, and at the speed the buggies get up to, plus their rather small size, it’s not enough to produce downforce. There’s not the surface area or the speed there.

So how are your normal wings and bodies producing more grip? Basically drag. If you look at a high downforce wing or a touring car body that people say gives more front end, usually they have a very steep front profile. This produces the drag. Drag itself doesn’t produce more downforce but what tends to happen is a cushion of air is built up, increasing the density more then in other areas and thus pushing the car down a bit. Of course at this point the air is having trouble flowing over the car so it isn’t terribly efficient but that doesn’t matter so much on scale racers.

So how does this relate? Well making parts aerodynamically efficient is a bit pointless in this scale. Yes if you’ve got a giant front upright you’d want to try and find a way to minimise it’s drag impact, but that’s about it. Making things like wishbones so they’re an aereo device won’t help, they’ll be no better then a conventional one.

Of course on the subject of wings there is a school of thought that says a multi element wing would produce some efficient downforce, but it would be rather fragile and at the end of the day be no better then a drag inducing wing for our purposes.

Sorry if that comes out a bit know it all, and feel free to argue, aerodynamics is a black art at the best of times. Now if we could just come up with some decent body shell cooling ideas…

Oh on the subject of the actual car design itself, I’d go with mass centralisation, a balanced left to right weight distribution and then find out what front to back weight distribution works best, probably around 55/45. And then there’s suspension geometry and all that fun stuff to play with… Good luck!

wow, matey, you know loads on aerodynamics. Do you have MSN? If so, could you PM me ur addy? I need to talk to you regarding some ideas I have.

I have taken into consideration yuor points. thanks;)

I must disagree with the differences between wings (in off-road at least) being purely drag, they do create a downward pressure of some sort. Different sized wings make a big difference to how the car behaves in the air, big wing on the back = nose up, front wing = nose down.
I don't see how that could be caused by drag alone, as surely with the wings being rigidly attached to the car the drag relative to the forward movement acts on the whole car. There must be downforce of some description happening or we wouldn't see different behaviour in the air by altering the wings at either end of the car.

ok, now I am confused LOL:o

i can vouch for what rich has said there, my losi xxx4 used to be a pain in the air at landing on the arse end, i dropped a massive yokomo bx wing on it fully uncut and it made the car perfect in the air ! = very happy bunny ! :D

http://users.telenet.be/elvo/


chapter 7 :)

That makes no sense.. if you are struggling with the car being nose high, how can an even bigger rear wing help? it should make the problem worse :confused:

that is one of the best sites on set up ive ever seen
very in depth and explains everything

nose dive sorry, i also shifted the cells to the back and changed the wing

yeah that site is very helpfull, its intresting ot read too!

kev

I agree with the 'moments around the CoG' theory, that drag above the CoG will turn the car onto its back wheels as Elvo points out.

I also agree with the 'air damn' theory, if air hits a surface and is forced upwards, there must be a force downwards that the air is giving the car (every action has an equal and oposite reaction)

but low pressure and high pressure enduced downforce is not really that much of a deal at our scale.

ok dokey cheers, I have a few ideas now:D

Yeah this is the fun part of aerodynamics, we just don’t know and I have to stress I’m an amateur at it. Don’t have a nice doctorate in it or anything…

Anyway, Richard you’re quite right in what you’re saying, I was just illustrating the differences between efficient aerodynamics, ie a multi element wing with negative lift properties (an aircraft wing upside down sort of thing) and the scoop wings we tend to run on the buggies. If you have a big wing, or a front wing then yes you’re going to catch more air, pushing you down some as you drive forward, but to does have to be at quite an angle to have an effect, thus the drag being caused in that way.

I understand what you were getting at before, I'm no expert either lol :p

That's half the fun of this hobby, you never stop learning things :)

do you think we are that bothered about aero drag?

especially in off-road, have you ever been to a track and thought that you should take off you super 'bod flap' wing off the back of your car because you are not fast enough down the straight?

half the time we are not running our fastest motors because we can reach speeds too fast for the track.

Nope Chris, I’m fully aware that no one is worried about aero drag. I was just using it as an example to explain why making smaller components such as wishbones aerodynamic wouldn’t be worthwhile. That’s all, I’ll go back to lurking now.

Don't go back to lurking, I was not aiming that drag coment at you, just general opinion really.

you have added some interesting ideas and the topic became very interesting after you post(s)

yeah, dont lurk, post. If I stopped posting everytime I got slagged, I wouldnt be here:D

Ok, yeah I shouldn’t read boards at 3am, really not conductive to communication. Thanks guys, just glad to help, as it were.

Here's what I'd like to see in a new 2wd.

- Rear Saddle-Pack cell Location. (Yokomo BX style)
- Motor near center of the car. (Yokomo BX style)
- Adjustable angle rear wing mounts.
- Belt drive to make it forgiving.
- Servo mounted low and close the front of the chassis with stearing arms above. (Losi JRXS style)
- 4 screws to remove the diff.

you will be pleased with the Aero2 then mate, accept the belt drive bit:rolleyes:

Having raced TC`s for the las decade of so this has been a "tuning" feature and created no end of debates on the effects of aero dynamics on toy cars, now from the use of a minature wind tunnel and touring car body shells the shape of the body only creates downforce up to 12 mph :eh?: after this it is actually drag that does the rest as air gets up inside the body and flares the sides etc.

I know buggys are a different shape but the wing will act as a stabiliser in the air just as it does on a TC at high speed. Aerodynamics is like everything else in racing its a compromise!!

A guy that races at lawford buggy club is running a car similar to what you describe, might still be pics on there site.

There is a pic of that car on this site. It's my dads car that runs a CAT 3000 chassis and a fireblade front end.

Can i get your msn tyrc. Or can u add me at [email protected] *anyone can if they wish*

added you mate;)

As regards rear wheel steering - I drove a development RWS 1/8th buggy once produced by a local model shop. All was good until it slid up to a track marking rope.........

You just can't steer away from the rope! To get the front of the car to point away and back to the track you have to turn in to the rope, which doesn't work. And if you steer away from the rope with the back of the car, thr front end points straight back at the rope!

That idea was quickly shelved I believe.

I did make a 4WS CAT XLS years ago when it had the old style rear hub carriers that allowed you to alter the toe via a threaded rod. Lots of bellcranks and pivots later it did actually work - the rear steer was about 50% of the front. But just too heavy and fragile to be competitive.

thank you ty. i first saw you at trcz. but then you kinda dissapeared. few people wondered where you went lol.

4ws cars
 

in the early 80s mugen had a 4ws car called the bulldog mosy of us that raced them locked the rear steer it was pretty much usless

The CADs have been created, I can tell you it does not feature rear wheel steering. Why change a formula that works so well? I think innovation should be through other items, and will be spending more time testing and setting it up, than trying to get the rear wheels to steer.

However, I tried a Lola shell on my tc tonight, it was the dogs, so at the minute I am open to suggestions.

The force with TYRC I think it is, not enough though I fear this will be.

is this some jedi yokall:D

we got darth vader, and yoda now...

Thanks for the compliment :confused: