View Full Version : foward wheel drive will be better
Noob33
11-13-2004, 01:46 AM
i belive front wheel drive will be better cause back would get you whellies and stuff that you dont get points it could mess up something :confused:
RS4rally1124
11-13-2004, 11:32 AM
been being made for a while good to c some competition in this class. and let me tell u fwd cars are a lot harder to build than u think. the dynamics of stearing are a pain along with the fact that there isnt a primarily front wheel drive car. i will tell u i started with a old rally car and have made most things custom now. if u want to look at it go check out an old issue of touring cars they made one out of a pro but by using their formula i could not put power to the ground due to todays powerful motors.
JT
Wouldn't a front wheel drive car be extreamly hard to handle at high speeds. Since your drive would also be what you steer with, i would imagine there would be alot of over steer.
ducati777
11-15-2004, 02:15 PM
@MGS... Good question. Typically a FWD car will understeer due to being able to pull the rear end. A RWD is a little like an upside down pendulum, and prone to oversteer... least more so than a FWD which is like a normal pendulum and will tend to track in the direction of the front wheels.
I think thats why most have agreed that 4wd is probably the best choice. Its a good compromise.
I'm also wondering about traction issues. You'd have to have some wicked front weight bias... which makes me think the car would handle funny...
Guess there's only one way to tell really. Experiment!!!
I think i will experiment with that. Do you think I could take the rear drive belt off my 4-tech. In theory it should work.
boroef
11-15-2004, 04:57 PM
if u have wicked front-end weight bias, u will have tons of understeer.
any front heavy car will push in corners. if u want to combat understeer, stiffen up the rear end a lot...and put a swaybar back there if possible.
RS4rally1124
11-16-2004, 03:15 PM
which is why u dotn race them but u do drag them better.
JT
ducati777
11-16-2004, 05:46 PM
I don't know about "better" I think there is a lot of debate on RWD vs FWD for drag racing... RWD has a big advantage due to weight transfer, and while FWD drag cars have come up in leaps and bounds in the last few years... I'll believe FWD is better when we see top fuel go front wheel drive. Kinda like you don't see many tractor pulls using front wheel drive.
But I digress! As far as the competition at hand, I think understeer is probably a good idea. Considering the car is going to hopefully be travelling in the triple digits, I'm doubting anyone wants oversteer. Don't get me wrong here, drifting an RC at 100+ mph would be really really cool, I just don't see it as the way to go in this competition.
As far as your 4 tec... sure you can take a belt off. Tricky part is the 4tec has a fairly balanced front to rear weight bias, which I THINK will cause excessive amounts of wheelspin. When was the last time you saw a rear engine, front wheel drive 1:1 car? (cool)
When Tamiya did their FWD lecto cars they put the motor and much of the tranny in front of the front axel to get the weight forward.
About the fwd drag racing. Why is fwd good for drag racing? I always think of fwd and rwd as a, push pull principle. It seems harder to pull than it is to push the same weight.
BJoeHandley
11-17-2004, 01:25 AM
Hey mgs9 which 4-Tec do you have?
If it's the electric, it'll suck, it's got more weight over the rear that the front and it will spin the front tire on take off. I've also noticed some torque steer on mine and would almost prefer awd or rwd to fwd because of that.
If it's nitro, I don't know, I've only run awd and rwd (rwd is good for doing donuts!) and I can't imagine it would be any better than the electric.
Chris LaPanse
11-17-2004, 02:28 AM
FWD isn't good for drag racing. Think of it this way. When you floor it from a stop, the weight shifts rearward. This results in a FWD car loosing traction, and a RWD car gaining traction.
Its the electric 4-tech. Im not going to try it, it would be a waist of time.
Apostolis
12-07-2004, 11:11 PM
I never liked fwd to be honest, they seem like they are pulling the car instead of pushing it...
BJoeHandley
12-08-2004, 01:16 AM
I hope you're being sarcastic?!
OpIvy
12-08-2004, 09:56 AM
if this event isn't on a straight.. fwd cars will have better handling when braking for corners..
-Nick
ducati777
12-08-2004, 11:43 AM
Uhhhh WHAT?
How does FWD or RWD change your braking???
Apostolis
12-08-2004, 02:27 PM
@BJoeHandley
Eh? I just said I don't like fwd car's, what's wrong with that?
For a drag race, 4WD (or RWD) rocks. As people said, the weight
of the car is transferred backwards during acceleration, which increases the traction of the rear tires but decreases the traction in the front.
After accelerating, however, and assuming the track is entirely high speed stuff (not necessarily straight, just very fast, like an oval), FWD will have the edge. Initially, 4WD seems like the best, handling wise; And it is the best.
But the additional friction of the drivetrain at such speeds is a killer for anyone who attempts to break a speed record, and the additional handling benefits of a 4WD are entirely unnecessary at such speeds. RWD, 4WD or FWD, you are just not going to have wheelspin at 100MPH, and we're not talking about high lateral grip either - it's a speed course. So cornering ability is a distant second to the primary requirements - stability and efficiency.
So apart from the phase of acceleration, FWD is probably the best.
Why?
It understeers instead of oversteering - the additional load put on the front tires by having to accelerate the vehicle as well as steer it, makes them slide first during side loads. It's less cool, yes, but MUCH easier to control.
Any wheelspin you might encounter will never take the car out of it's line - you will just temporarily lose steering ability (as the steering wheels now spin without traction), until you let off the accelerator to calm things down, and then you just regain steering and continue accelerating. Compare this with having to correct back end slides that develop into fishtailing at 60MPH+... :eek:
So I'd NEVER consider FWD in RC for anything BUT high speed runs. For that, it's perfect!
Combatcm
12-08-2004, 11:33 PM
I see everyones argument and I think FWD would be the best way to control a car. For battery space, the steering servo is in the front, and the drivetrain if you make it that way, but behind that it can be all batteries. Accelerating or decelerating keep the car stable. Past 35mph it won't matter what drivetrain you have for top speed.
The only argument is being able to get that top speed. The contest may even just a plain old drag race for people to pull the most they are able out of the track before its time to decelerate. But radio range will be a problem, the most I've ever got out of my radios is 500 feet. But that's another argument nobody thinks about.
BJoeHandley
12-09-2004, 01:46 AM
If you're doing a long straight line run, like they do at the Bonneville Salt Flats, fwd may work well, but if you're drag racing or running some kind of corners like on an oval or road coarse, rwd's better balance will be an asset.
OpIvy
12-09-2004, 04:35 AM
ducati, unless you're using mechanical brakes, I only run electric, so for electric brake, fwd would stop better..
just like when your on a bycicle.. if you slam on rear brake, you slide. if you slam on front, you flip over, because of weight transfer. that's all.
-Nick
ducati777
12-09-2004, 01:49 PM
There you go Nick, you assume that the drive system and the brake system are the same. When it comes to electrics you're right, but we dont' all run electric. Consider an 8th scale buggy could be set to FWD and rear wheel braking only...
No one is going to argue that front wheel brakes are worse, but you said front wheel drive... Anyway no harm no foul, I just like to be specific.