[TeriyakiSawce]

Ive been having a debate with a friend about the turning circle of different drivetrains (FWD, RWD and AWD) Which has the largest turning circle and which has the smallest? If you could proved a brief why that would be great :D

My opinion:

1. RWD (smallest)
2. FWD
3. AWD (largest)

[Qmx323]

http://en.wikipedia.org/wiki/Automobile_layout#Rear_wheel_drive_layouts

doesnt mention AWD turning circles but it does confirm that RWD has the smallest turning circle and FWD has the biggest

[bloodmack]

i think it depends more on the wheel base more than the driveterrain.. EVO 94' wheel base VS Supra MK4 94' wheelbase for example..

[Berzerker]

You would need to get 2 cars that are the same but with the drivetrain changed to get a proper comparison.

Berz out.

[Nightwalker]

It would be pretty specific to X car vs X car. Some have rear wheel steering, some just have wildly different dimensions, etc.

I suppose not having driveshafts that need to reach the turning wheels would give RWD an advantage though.

[CP.AR]

My aunt had a Volvo 740 way back when
holy shit that thing could turn on a DIME

[Berzerker]

I would think that RWD having to push the car around would make the radius bigger than a FWD that pulls the car tight?

Berz out.

[eurochevy]

all depends on wheelbase, size of wheels etc theres too many variables, theoretically there is no difference between a fwd/awd/rwd this is basically an impossible question

[Ferra]

totally car dependent

The RSX has a short wheelbase but a horribly WIDE turn radius
My family had a sienna with much longer wheelbase but a smaller turn radius than a RWD e90


actually...to solve your question, just check whether a RWD e90 has better turn radius than a AWD e90

[subwoffers]

My car has a turning radius of 26.2 feet. You jelly?

A smart car has a TR of 28feet.

[ilvtofu]

Doesn't really have much to do with the drivetrain as others have said.

The new subaru impreza in my experience has been very good, and my mom's W203 C class was pretty good for u-turns too, X3 was not as good and has similar wheelbase so yeah it's pretty specific to each car

Then again with some RWD you can do this kind of shit at a stand still :troll:
http://www.youtube.com/watch?v=X416wXG5Yxw

[MindBomber]

I would think that RWD having to push the car around would make the radius bigger than a FWD that pulls the car tight?

Berz out.

This.

I suspect a 4ws Prelude could defeat almost any competitor in a turning radius contest.

[godwin]

It has nothing to do with FWD, RWD or AWD.. but everything to do with engine layout, *WD is just an after effect.

Assuming all cars' wheel base and track are the same:

Engine layout and engine configuration limit the the maximum angle the wheels can turn in, hence affecting the turning radius.

Rear engine layouts that have the smallest turning radii (because there is no engine up front to constrain the angle of turn) vs front wheel longitudinal then front wheel latitudinal.

You can have higher angle of turn on longitudinal front engine layouts. (eg Audi A6/ A4 FWD will have smaller turning radius than their A3 FWD). However Inline engines eg BMW or old Mercedes will have even smaller radius since the engine packaging is thinner... hence allowing the wheels to turn in even more.

Latitudinal layouts Honda / Volvos (especially their i6) etc have larger turning radius since their wheels cannot turn in as much. They try to compensate by making their cars much wider (so they also claim that they make it more roomier)

4WS / pushing or pulling theories have relatively small effect when compared with what different engine layouts can do.

To test this in daily life, take a 3 series RWD, C class V6 RWD and a TL/TSX on a 2 street 3 point turn. 3 series can usually do it in 2 while the rest have to do full 3.

[InvisibleSoul]

This.

I suspect a 4ws Prelude could defeat almost any competitor in a turning radius contest.

4WS is hacks.

But despite that, I don't believe it has the tightest turning radius.

[InvisibleSoul]

Wikipedia says this about RWD:

Steering radius — As no complicated drive shaft joints are required at the front wheels, it is possible to turn them further than would be possible using front-wheel drive, resulting in a smaller steering radius for a given wheelbase.
But at the end of the day, it still ultimately depends on each car model itself... how far they decided to lock the steering and such.

[dark0821]

i rmbr clarkson comparing a SL65 Black to a normal SL350... =.=
the turning radius on the Black was far bigger than SL350...

so my friend tested a EVO VS lancer GTS for U Turns... Lancer made it with full lock on a normal residential street... EVO...not so much

which leads us to assume, higher performance cars probably have a diff geomentry that makes it having a bigger turning radius? LOL, no idea what i am talkin abt.. so just a hypothesis

http://www.youtube.com/watch?v=iXJH2Q9sW_4&hd=1

skip to 6:02 to see what i am talking abt...

[godwin]

It is called wider wheels, which reduces the turn in angle. Not to mention you need more force to turn in when you are going high speed.


which leads us to assume, higher performance cars probably have a diff geomentry that makes it having a bigger turning radius? LOL, no idea what i am talkin abt.. so just a hypothesis

[!LittleDragon]

Toyota Echo hatchback that I had as a courtesy car couldn't make a U turn in a 2 lane road without doing a 3 point. My wider, longer wheel base, RWD, fat tire'd MR2 Turbo does a U turn on the same road without problem

[Noizz]

so my friend tested a EVO VS lancer GTS for U Turns... Lancer made it with full lock on a normal residential street... EVO...not so much

which leads us to assume, higher performance cars probably have a diff geomentry that makes it having a bigger turning radius? LOL, no idea what i am talkin abt.. so just a hypothesis

You're on the right track, higher performance cars will have more components in the engine bay. Beefier engine and transmission will take up more space, and when you add the turbo into the lancer, it'll take up more space. As a result, the steering angle of the front wheels will be limited more so than a basic model.

[falcon]

You guys are all morons. It has nothing to do with drivetrain and everything to do with how the knuckles are designed and how much "angle'' your front wheels can get when you are at full lock.

[Berzerker]

That's why I said you need 3 cars that are exactly the same only 1 being RWD 1 being FWD and 1 being AWD. Also speed is a huge factor.

Berz out.

[shtone]

we talking about turning radius? i noticed the 2 door coupes have a bigger turning radius then 4dr sedans...

[Presto]

You guys are all morons. It has nothing to do with drivetrain and everything to do with how the knuckles are designed and how much "angle'' your front wheels can get when you are at full lock.

Yup. Something big, such as a Dodge Ram 1500, has a mid-20's turning radius, while a compact, like a Corolla, pulls a wide 36 footer.

[77civic1200]

You guys are all morons. It has nothing to do with drivetrain and everything to do with how the knuckles are designed and how much "angle'' your front wheels can get when you are at full lock.

Mostly true. While it does completely depend on the max angle you are getting out of the front wheels, its also true that a fwd vehicle would have a lower max because of the limits of the driveshaft. A rwd vehicle has more potential to have a small turning radius, if the desire was there.

[Harvey Specter]

My A5 has an much wider turning radius compared to my e92.

[falcon]

Mostly true. While it does completely depend on the max angle you are getting out of the front wheels, its also true that a fwd vehicle would have a lower max because of the limits of the driveshaft. A rwd vehicle has more potential to have a small turning radius, if the desire was there.

No. Not mostly true. Completely true. Everything you said, comes back to the same thing. The amount of angle the tie rods/steering rack will give to your wheels.

[Mancini]

I would think that RWD having to push the car around would make the radius bigger than a FWD that pulls the car tight?

Berz out.

Perhaps if this was a turning circle drifting competition at full steering lock.

You guys are all morons. It has nothing to do with drivetrain and everything to do with how the knuckles are designed and how much "angle'' your front wheels can get when you are at full lock.

This.

[hk20000]

therefore, you can have a much tighter turning radius in a Subaru Impreza than a Lancer Evolution, yet maybe not as much turning radius as a Lancer GTS.

Let's put another 2 very similar shaped cars together: Smart Fortwo and Toyota iQ. iQ will turn inside the Fortwo turning radius, but iQ is FWD the Fortwo is RWD.

Food for thought. So the argument is moot.

[underscore]

this is a stupid question, as stated before turning radius has nothing to do with the drive wheels, unless you're breaking them loose. wheelbase length plays a small role, and the steering angle at full lock would be the most important thing.

i rmbr clarkson comparing a SL65 Black to a normal SL350... =.=
the turning radius on the Black was far bigger than SL350...

http://www.youtube.com/watch?v=iXJH2Q9sW_4&hd=1

skip to 6:02 to see what i am talking abt...

The reason why the Black would have a bigger radius is a combonation of things, including the wider tires and lower suspension that require less steering angle in order to avoid rubbing.

That's why I said you need 3 cars that are exactly the same only 1 being RWD 1 being FWD and 1 being AWD. Also speed is a huge factor.

Berz out.

why can't I fail you? Drive train is irrelevant here.

[77civic1200]

No. Not mostly true. Completely true.

Bullshit. You said "It has nothing to do with drivetrain" Thats wrong. Its not the major factor, as I explained, but drivetrain can limit the available angles.

[mmmk]

g35 coupe turns a HUGE as circle compared to my friends clk or gf's civic....
so i would have to say it depends on the car

[jackal]

no front axles makes a big difference. i run modded front knucles and get 52deg in the front and the only limiting factor is that i hit the inside frame and tension rods. i can pull a u-turn in 2 standard car lanes.

http://farm5.static.flickr.com/4116/4886038962_efa917c0fe.jpg

[falcon]

I can't believe the utter nonsense in this thread.

[Berzerker]

I think my statement is the truest of all and yet it seems people can't understand the basic principles falcon and I are trying to explain.

Steering is angle what makes a car turn. In order for this to be a fair comparison you need 2 identical cars but one being FWD and one being RWD. THEN you have to drive them in a circle. Speed will play a huge factor in the size of the radius though so at nominal speed I would say they are going to be exactly the same. However as speed increases the cohesion of the front tires will be the contributing factor of the overall radius. The faster you go the wider the radius will be. This is where the difference between FWD and RWD would come into play.
Which one allows for better cohesion and retaining a tight circle.

Berz out.

[J____]

mercs can turn on a dime. My datsun has horrible turning radius, so does my rx lol

[Presto]

Steering is angle what makes a car turn. In order for this to be a fair comparison you need 2 identical cars but one being FWD and one being RWD. THEN you have to drive them in a circle. Speed will play a huge factor in the size of the radius though so at nominal speed I would say they are going to be exactly the same. However as speed increases the cohesion of the front tires will be the contributing factor of the overall radius. The faster you go the wider the radius will be. This is where the difference between FWD and RWD would come into play.
Which one allows for better cohesion and retaining a tight circle.


I think that's a skidpad test. Turning radius has nothing to do with lateral Gs.

[SpuGen]

:whistle:
http://en.wikipedia.org/wiki/Ackermann_steering_geometry

[noventa]

thIn my opinion, Falcon said it best. The OP is confusing the audience with his choice of possible answers. If there was another choice, it would read
d)none of the above

Like Falcon said, you would only have to consider the maximum steering angle plus width and length of the wheel base. On paper with this data alone, you should be able to calculate the turning radius of the typical car with a fixed rear axle.

However in real life, you will notice that at full lock, the angle of the tires at full lock will be slightly different. This is because the manufactured is using some variation of th Ackermann steering geometry (look it up). This type of arranging is used in order to solve the problem of the outer wheel having to travel a farther distance when tracing out the turning circle. Knowing this, we can reach a very close approximation of a car's turning radius with the equation

turning circle radius = the width of the wheels divided in 2 plus length of wheelbase divided by SIN of both steering angles divided by 2.

Imagine if you were plotting a cars turning radius on paper using xy coordinates. You would be plotting the XY coordinates of a semi circle in order to determine the distance of X from where it origin. Because you are plotting a single point, you will have to convert your real life data according. That is why to our best approximation, we divide the length and width of the base by 2, and average out the steering angle.

In real life, steering geometry is a usually a derivative of drive train layout. However, ultimately, it is still the steering angle that largely determines how tightly a car can turn. Knowing the drive train configuration is not sufficient information to determine the turning radius of a car.

And really, if it was up to layout, the tank would win hands down!

[falcon]

Finally someone knows what they are talking about.

[underscore]

I think my statement is the truest of all and yet it seems people can't understand the basic principles falcon and I are trying to explain.

Steering is angle what makes a car turn. In order for this to be a fair comparison you need 2 identical cars but one being FWD and one being RWD. THEN you have to drive them in a circle. Speed will play a huge factor in the size of the radius though so at nominal speed I would say they are going to be exactly the same. However as speed increases the cohesion of the front tires will be the contributing factor of the overall radius. The faster you go the wider the radius will be. This is where the difference between FWD and RWD would come into play.
Which one allows for better cohesion and retaining a tight circle.

Berz out.

No, you just can't understand that you're talking about the wrong fucking thing.

[jstn86]

the real answer is...

WHO GIVES A SHIT?

if your car has horrible turning radius, then just DEAL WITH IT.

if your car has awesome turning radius, then just turn LIKE A BAWS.

is it really that important to discuss?

[bloodmack]

OP's question was what drive-terrain has the best turning radius, yet we start to talk about why its not the drive terrain. :lol:

Noventa, I gotta ask why did you fail my post if its partially correct?

Falcon, its not that we're morons, its just we post what we know of / think.

This thread is so much fail :P