same weight, power, etc. fwd v rwd... which is faster?

[koolchris99]

brother asked me a stupid question today on the way back up the m5

there are two cars. Both identical, same weight, same power at wheels, same drag, etc.... but..

one is rwd, the other fwd.

which is faster and why??

[Yazza54]

Engine over the drive wheels in fwd but not in rwd?

[Lord Flathead]

If they're both identical how can they be different

[koolchris99]

let's call it a 130i

one fwd one rwd.

the weight distribution is the same.

[koolchris99]

Lord Flathead said:

If they're both identical how can they be different

there is a "but...."

[thinfourth2]

Go look at the BTCC rules the RWD cars have to carry more weight.

So round a track RWD is quicker

[poing]

fwd has less drivetrain losses so perhaps that would help but really you need to define "faster". Faster in a straight line? Faster round a track? Faster in the dry/wet?

Too many criteria to take into account.

[OllieWinchester]

Less transmission losses in the FWD one, better traction off the line in the RWD one.

[nyxster]

Engine over wheels, but isn't weight transferred backwards during acceleration?

I can always remember my FWD cars feeling very "light on the nose" during acceleration.

Having experienced the Alfa GTA scrabbly wheelspin vs a M3 power delivery I would say anything above 200BHP and RWD has it.

otherwise F1 cars would be FWD surely?

[koolchris99]

1/4 mile race. dry conditions.

it's bhp at wheels that's the same.

I thought rwd but couldn't explain why.. I need maths..

[spyder dryver]

No mention of lap times or acceleration in the question.
Faster must mean top speed.
Cars will be identical on top speed.

[thinfourth2]

koolchris99 said:

1/4 mile race. dry conditions.

it's bhp at wheels that's the same.

I thought rwd but couldn't explain why.. I need maths..

If there is enough power to over come traction then RWD will accelerate faster initially due to weight transfer.

if not enough power to break traction then exactly the same if all other factors such as gear ratios etc are the same

[snuffle]

In the FWD, Can the rear seats be folded down?

[koolchris99]

snuffle said:

In the FWD, Can the rear seats be folded down?

nop. even weight...

no go faster stripes either

and both cars are same colour,

[redstu]

snuffle said:

In the FWD, Can the rear seats be folded down?

now we all know that does make a difference!

[collateral]

thinfourth2 said:

koolchris99 said:

1/4 mile race. dry conditions.

it's bhp at wheels that's the same.

I thought rwd but couldn't explain why.. I need maths..

If there is enough power to over come traction then RWD will accelerate faster initially due to weight transfer.

if not enough power to break traction then exactly the same if all other factors such as gear ratios etc are the same

^^^ this

[koolchris99]

collateral said:

thinfourth2 said:

koolchris99 said:

1/4 mile race. dry conditions.

it's bhp at wheels that's the same.

I thought rwd but couldn't explain why.. I need maths..

If there is enough power to over come traction then RWD will accelerate faster initially due to weight transfer.

if not enough power to break traction then exactly the same if all other factors such as gear ratios etc are the same

^^^ this

so the X power pushing an object is the same as X power pulling an object?

I think mr physics would say otherwise, but dont have him to hand

[collateral]

koolchris99 said:

collateral said:

thinfourth2 said:

koolchris99 said:

1/4 mile race. dry conditions.

it's bhp at wheels that's the same.

I thought rwd but couldn't explain why.. I need maths..

If there is enough power to over come traction then RWD will accelerate faster initially due to weight transfer.

if not enough power to break traction then exactly the same if all other factors such as gear ratios etc are the same

^^^ this

so the X power pushing an object is the same as X power pulling an object?

I think mr physics would say otherwise, but dont have him to hand

And what if it was mid-engined?

[Cost Captain]

This is a pretty poor question to be honest. If its just in a straight line it will be the rwd car due to weight transfer. this is only providing the weight distribution isn't rediculously far forward to start with and that the CoG is high enough to cause noticable weight transfer.

around a track then there are far too many factors.

[koolchris99]

Cost Captain said:

This is a pretty poor question to be honest. If its just in a straight line it will be the rwd car due to weight transfer. this is only providing the weight distribution isn't rediculously far forward to start with and that the CoG is high enough to cause noticable weight transfer.

around a track then there are far too many factors.

not that poor a question, i presumed it would be rwd but i wanted to know the physics.

This is a test between a rwd and fwd, but they arnt completly identical.
http://home.comcast.net/~cvetters3/test1.htm