Weight
#3
Anything on the left side of 3,000 Lbs is good.
Ive got a fanatical appreciation for lightness so I totally understand your concerns but by todays standards, a four seat, rear wheel drive, 250 hp car that weighs less than 3,000 is phenomenally light. For example, the new MINI which is wrong wheel drive, only has 115 hp & is shorter than a Miata by several inches weighs 2,550 Lbs.. Don't get me started on that pig of a 350Z; take a buddy along & you'd still weigh less dispite having two more seats.
Last edited by RX7 Guy; 11-06-2002 at 07:45 PM.
#4
Hmmmm.... I'm also hoping for a light car... here's my previous post on the subject...
http://www.rx8forum.com/showthread.p...3175#post13175
Basically I don't know exactly if they were measuring the same thing but my 91 accord was bigger than this car and is listed only 3020 or somthing so I recon it's gonna be much lower than the previously listed 2970.
Hopefully it's 2790.... but a lot of guys here recon that's impossible... we'll wait and see I guess! I have a weigh bridge at work... so we can settle it once I get a car.
http://www.rx8forum.com/showthread.p...3175#post13175
Basically I don't know exactly if they were measuring the same thing but my 91 accord was bigger than this car and is listed only 3020 or somthing so I recon it's gonna be much lower than the previously listed 2970.
Hopefully it's 2790.... but a lot of guys here recon that's impossible... we'll wait and see I guess! I have a weigh bridge at work... so we can settle it once I get a car.
#6
We could shave off 113 Lbs. but at great cost.
BlueAdept,
All things being equal, rear wheel drive will add roughly 0.7 Lbs. of weight for each Ft Lb. of engine torque. So figure the RX-8 has about 113 Lbs. allocated to the prop shaft, chassis torsion load reinforcements & differential harness Its a necessary evil to avoid the massive understeer & unsporting handling associated with front wheel drive configurations.
All things being equal, rear wheel drive will add roughly 0.7 Lbs. of weight for each Ft Lb. of engine torque. So figure the RX-8 has about 113 Lbs. allocated to the prop shaft, chassis torsion load reinforcements & differential harness Its a necessary evil to avoid the massive understeer & unsporting handling associated with front wheel drive configurations.
#7
True...But Most Cars are Pigs Today
I agree by today's standards...it is relatively light...but I wouldn't say its impossible for it to come in lighter.
The Celica is not too much shorter than the RX8..has 180 HP...and weighs 2,500 lbs...and is arguably the best handling mass-produced FWD car. Obviously, a RWD car will weigh more with a longer drivetrain (maybe 200 lbs??).
I wonder just how much weight is added by making it a true four seater as opposed to a 2X2 (assuming they made the car shorter) and having the suicide doors.
Anyway, this car is still months away, so who knows, things may change. I've waited a year and a half, what's a few more months without having car payments!
The Celica is not too much shorter than the RX8..has 180 HP...and weighs 2,500 lbs...and is arguably the best handling mass-produced FWD car. Obviously, a RWD car will weigh more with a longer drivetrain (maybe 200 lbs??).
I wonder just how much weight is added by making it a true four seater as opposed to a 2X2 (assuming they made the car shorter) and having the suicide doors.
Anyway, this car is still months away, so who knows, things may change. I've waited a year and a half, what's a few more months without having car payments!
#8
Re: We could shave off 113 Lbs. but at great cost.
Originally posted by RX7 Guy
BlueAdept,
All things being equal, rear wheel drive will add roughly 0.7 Lbs. of weight for each Ft Lb. of engine torque. So figure the RX-8 has about 113 Lbs. allocated to the prop shaft, chassis torsion load reinforcements & differential harness Its a necessary evil to avoid the massive understeer & unsporting handling associated with front wheel drive configurations.
BlueAdept,
All things being equal, rear wheel drive will add roughly 0.7 Lbs. of weight for each Ft Lb. of engine torque. So figure the RX-8 has about 113 Lbs. allocated to the prop shaft, chassis torsion load reinforcements & differential harness Its a necessary evil to avoid the massive understeer & unsporting handling associated with front wheel drive configurations.
#10
Celica
Revhappy,
Interesting you mentioned the Celica I debated between using it as a Best in Class example or using the MINI as a Worst in Class example. Dont get me wrong. I really admire the MINI, actually, I admire anything that isnt a ^%#$$@ SUV these days.
Anyway, the Celica is about as light as you can get using conventional engineering. Everybody raves about Hondas VTEC technology Hello, what about Yamahas contribution to the Celicas super high power to weight ratio engine which contributes greatly to the Celicas overall lightness. But you already touched on my point which is that the RX-8 will weigh something like 400 Lbs. more than the Celica. For that, you get more: power, room & structural rigidity all with the drive wheels located at the correct end of the car.
Interesting you mentioned the Celica I debated between using it as a Best in Class example or using the MINI as a Worst in Class example. Dont get me wrong. I really admire the MINI, actually, I admire anything that isnt a ^%#$$@ SUV these days.
Anyway, the Celica is about as light as you can get using conventional engineering. Everybody raves about Hondas VTEC technology Hello, what about Yamahas contribution to the Celicas super high power to weight ratio engine which contributes greatly to the Celicas overall lightness. But you already touched on my point which is that the RX-8 will weigh something like 400 Lbs. more than the Celica. For that, you get more: power, room & structural rigidity all with the drive wheels located at the correct end of the car.
#11
The Celica uses some pretty crazy stuff to acheive that light weight. The engine block, for example, is made of a lightweight aluminum composite that allows only 5 mm between cylinders. The sunroof is made of plastic rather than glass for addition weight savings. I could go on and on.
Of course, the RX-8 has some extreme measures to save weight. Carbonfibre driveshaft, for example.
So why the descrepency? Lots of reasons, but these are the main ones:
1. Chassis stiffening - much required on the RX-8 because of its unusual door layout and no B-pillar
2. RWD (as mentioned above).
3. Higher vehicle content (more goodies to play with)
4. Two extra doors.
5. Overall big size
By the way, comparing the RX-8 to a 91 Accord isn't fair, although on the surface it appears to be. The amount of safety gear that cars today have compared to cars a decade or more ago is ridiculous. Much more stiff, side door beams, multiple airbags, etc. Ever check what a 2003 Accord weighs?
Of course, the RX-8 has some extreme measures to save weight. Carbonfibre driveshaft, for example.
So why the descrepency? Lots of reasons, but these are the main ones:
1. Chassis stiffening - much required on the RX-8 because of its unusual door layout and no B-pillar
2. RWD (as mentioned above).
3. Higher vehicle content (more goodies to play with)
4. Two extra doors.
5. Overall big size
By the way, comparing the RX-8 to a 91 Accord isn't fair, although on the surface it appears to be. The amount of safety gear that cars today have compared to cars a decade or more ago is ridiculous. Much more stiff, side door beams, multiple airbags, etc. Ever check what a 2003 Accord weighs?
#12
2x2 Light RWD Coupe
RX7 Guy.
The 2X2 light weight RWD sport coupe has got to be one of the rarest cars.Would it be fair, given the Celica example and the FWD -RWD weight conversion, that given current technology, you could see a RWD sport coupe as light as 2,613 lbs (2,500+113)? That would put us near the M3 in terms of the power-rate ratio!
The Yamaha in the Celica is nice, but it needs to rev higher...the power band is a little too narrow.
The 2X2 light weight RWD sport coupe has got to be one of the rarest cars.Would it be fair, given the Celica example and the FWD -RWD weight conversion, that given current technology, you could see a RWD sport coupe as light as 2,613 lbs (2,500+113)? That would put us near the M3 in terms of the power-rate ratio!
The Yamaha in the Celica is nice, but it needs to rev higher...the power band is a little too narrow.
#13
Where's the weight???
BlueAdept,
I changed the steel prop shaft on my 87 RX-7 about a year ago & Id guess that it weighed about 15 Lbs.
I know that the RX-8s prop shaft is carbon fiber but its longer & it has to carry an additional 26 Lbs. of engine torque (162 Vs. 136) so itll probably weight about the same.
Accessing the weigh increase associated with rear wheel drive configurations is very complicated For instance, if the car already has great chassis rigidity, not much weight will need to be added to carry the torsion loads imparted by the prop shaft. Also, FWD transaxles weigh much less than a transmission & differential individually but FWD transaxles have problems like torquesteer which cant be assigned a weight value. The 0.7 rule of thumb I used assumes an average length wheel base, longer wheel bases would have greater multipliers. It really goes on & on but Id say that 0.7 is a fairly decent way to estimate the weight penalty.
What materials are you basing that on?
I know that the RX-8s prop shaft is carbon fiber but its longer & it has to carry an additional 26 Lbs. of engine torque (162 Vs. 136) so itll probably weight about the same.
Accessing the weigh increase associated with rear wheel drive configurations is very complicated For instance, if the car already has great chassis rigidity, not much weight will need to be added to carry the torsion loads imparted by the prop shaft. Also, FWD transaxles weigh much less than a transmission & differential individually but FWD transaxles have problems like torquesteer which cant be assigned a weight value. The 0.7 rule of thumb I used assumes an average length wheel base, longer wheel bases would have greater multipliers. It really goes on & on but Id say that 0.7 is a fairly decent way to estimate the weight penalty.
#15
Weight
could you see a RWD sport coupe as light as 2,613 lbs (2,500+113)?
#16
Re: True...But Most Cars are Pigs Today
Originally posted by revhappy
I agree by today's standards...it is relatively light...but I wouldn't say its impossible for it to come in lighter...
I agree by today's standards...it is relatively light...but I wouldn't say its impossible for it to come in lighter...
---jps
#17
Re: Re: True...But Most Cars are Pigs Today
Originally posted by Sputnik
But remember, it costs money for it to come in lighter. So in reality, it IS impossible for a mass-produced $30k car with those options to come in any lighter.
---jps
But remember, it costs money for it to come in lighter. So in reality, it IS impossible for a mass-produced $30k car with those options to come in any lighter.
---jps
Hopefully it will be lighter, maybe it won't. Either way at under 3000 lbs, it says a lot for it's nimbleness. Now Mazda needs to fine tune suspension settings and let this thing rip on over to R&T and C&D... and we will have our cake and eat it too, and laugh in the face of all those nonbelievers
#18
Re: Purple
Originally posted by RX7 Guy
Grimace,
RE: Your points 1 5
I never knew big purple creatures could be so articulate & insightful. Ill never watch a Mickey Ds commercial the same way again.
Grimace,
RE: Your points 1 5
I never knew big purple creatures could be so articulate & insightful. Ill never watch a Mickey Ds commercial the same way again.
Thanks... I think! :D
#19
Originally posted by Grimace
By the way, comparing the RX-8 to a 91 Accord isn't fair, although on the surface it appears to be. The amount of safety gear that cars today have compared to cars a decade or more ago is ridiculous. Much more stiff, side door beams, multiple airbags, etc. Ever check what a 2003 Accord weighs?
By the way, comparing the RX-8 to a 91 Accord isn't fair, although on the surface it appears to be. The amount of safety gear that cars today have compared to cars a decade or more ago is ridiculous. Much more stiff, side door beams, multiple airbags, etc. Ever check what a 2003 Accord weighs?
2003 Honda Accord DX 4Cyl 160HP Manual Transmission - Curb weight 2989
2003 Honda Accord LX 6Cyl 240HP Automatic Transmission Curb weight 3309
2003 Honda Accord EX 6Cyl 240HP Automatic Transmission Curb weight 3360
Enough said!
Note: LX and EX models are not available in manual transmission. Information source Honda USA web site.
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