Interior/Exterior Weight savings in front
5th Gear
Joined: Nov 2003
Posts: 1,027
Likes: 0
From: Miami, Fl
Originally Posted by TonyB
I don't menttion wheels, tires, shocks, as they are at all 4 corners, so not purely the front. With that said, my 16's at 10.75 lbs made a world of difference
. And my front coilovers saved me about 3 pounds each, while the rears were like .2 lbs lighter only...I'll believe 8 lb 18" wheels when I see them
. But if price is no limit, I'm sure such a figure is attainable...
6th Gear
Joined: Apr 2003
Posts: 3,957
Likes: 2
From: a canyon, south Bay Area
Hi Thameth. Oh, I didn't forget them. I was referring to them above when I said "BBK" or a big brake kit 
. I have the WW 16" race kit, and waited for them as they would fit my 16's with zero spacers, and because of the weight-savings... and of course the improved stopping ability (less fade).
. I have the WW 16" race kit, and waited for them as they would fit my 16's with zero spacers, and because of the weight-savings... and of course the improved stopping ability (less fade).
You are so right!
Originally Posted by Tuls
each stock wheel is...like 40 llbs or something...I think he was talking about the weight savings....also in order to turn the mass you loose alot of time...therefore have 8 lbs of rotational mass insted of 40 would be better...not only for acceleration but for stoping and turning...no?
is that what you were not getting about the factor of four or am I still drunk from saint pattys...LOL
is that what you were not getting about the factor of four or am I still drunk from saint pattys...LOL
Matt
Turbius Maximus
Joined: Mar 2004
Posts: 4,416
Likes: 0
From: Infinity and beyond
I asked this my self just casue someone had asked about 15 the day I was talking with the engineer..he said that the mag is where the weight is...the CF barrel is virtually weightless....so it's would still be in the 8 lbs range maybe less but not by much...however...that's still amazing! heh heh
Originally Posted by Thameth
Will they be making 16in wheels?? How much would those weigh?? 4lbs?
Definitely interesting technology! Would love to see it come down in price in a few years. Though for now i'll stick to my 13lb Rota Slipstreams
Definitely interesting technology! Would love to see it come down in price in a few years. Though for now i'll stick to my 13lb Rota Slipstreams
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2nd Gear
Joined: May 2004
Posts: 136
Likes: 0
From: SO CAL
Originally Posted by Dr Obnxs
I don't understand at all. For a wheel, the unsprung weight has to do with the suspension response. Something called the "moment of inertia" (think of it as rotational mass) is used to calculate the amount of energy stored in the rotational kinetic energy. this energy, along with the kinetic energy associated with the speed of the car, which is proportional to the mass of the wheel, not it's moment, is what you counsider in 0-60 times, etc.
The moment is calcated in a bit of a messy way, but what it comes down to is it depends heavliy on the geometry. For a wheel like this, where the mass is removed from the rim, it REALLY LOWERS the moment of inertia, and will have a much bigger effect in 0-60 times than even th effect on suspension response.
And I have no clue what that factor of four is, or where it comes from.
Real bitchen wheels! I just fear what they cost.....
Matt
The moment is calcated in a bit of a messy way, but what it comes down to is it depends heavliy on the geometry. For a wheel like this, where the mass is removed from the rim, it REALLY LOWERS the moment of inertia, and will have a much bigger effect in 0-60 times than even th effect on suspension response.
And I have no clue what that factor of four is, or where it comes from.
Real bitchen wheels! I just fear what they cost.....
Matt
Alliance Member
Joined: Apr 2003
Posts: 4,100
Likes: 229
From: York, Pennsylvania
If you do the physics, it turns out 1# taken off the wheel is somewhere
between 1# and 2# taken off the chassis in terms of increasing
acceleration performance. Typically about 1.7#.
1# if all the weight of the wheel/tire is taken off at the center (axle),
and 2# if all the weight is taken off at the tread.
Of course weight taken off the wheel/tire helps reduce unsprung weight and
will help handling. (the suspension has less inertia to overcome moving up and down
over bumps, compressing and extending). Here it doesn't matter whether the weight reduction
is at the center or circumference or in between.
between 1# and 2# taken off the chassis in terms of increasing
acceleration performance. Typically about 1.7#.
1# if all the weight of the wheel/tire is taken off at the center (axle),
and 2# if all the weight is taken off at the tread.
Of course weight taken off the wheel/tire helps reduce unsprung weight and
will help handling. (the suspension has less inertia to overcome moving up and down
over bumps, compressing and extending). Here it doesn't matter whether the weight reduction
is at the center or circumference or in between.
6th Gear
Joined: Apr 2003
Posts: 3,957
Likes: 2
From: a canyon, south Bay Area
Less weight not only helps with acceleration, but it also aids in a more responsive suspension, improved braking, better gas mileage, and I would think less wear & tear... And while sometimes it can be free, such a quest can even be lucrative. I think I made 400 bucks on my rear seats .
BelowRadar, I got your PM and I'll be sending you that doc very soon...
.BelowRadar, I got your PM and I'll be sending you that doc very soon...
Originally Posted by Tuls
each stock wheel is...like 40 llbs or something...I think he was talking about the weight savings....also in order to turn the mass you loose alot of time...therefore have 8 lbs of rotational mass insted of 40 would be better...not only for acceleration but for stoping and turning...no?
In case you're not, a stock 16" X-lite weighs 17.6 lbs, a 17" R90 weighs 24.1 lbs and a stock 17" S-lite weighs 25.1 lbs.
Former Vendor
Joined: Jan 2004
Posts: 8,337
Likes: 4
From: oh10
Originally Posted by KevinR
You're kidding, right?
In case you're not, a stock 16" X-lite weighs 17.6 lbs, a 17" R90 weighs 24.1 lbs and a stock 17" S-lite weighs 25.1 lbs.
In case you're not, a stock 16" X-lite weighs 17.6 lbs, a 17" R90 weighs 24.1 lbs and a stock 17" S-lite weighs 25.1 lbs.
Thread Starter
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2nd Gear
Joined: May 2004
Posts: 136
Likes: 0
From: SO CAL
My TZ-10s wieghed in at 40.1 lbs (on a certified and calibrated scale). So my assumption was that the s-lites with runflats weighed 46lbs. So I saved 6 lbs per corner which equals 24 lbs. HERE is where my assumption went wrong...I read somewhere that taking a pound off of rotational mass equaled 4 lbs of sprung weight in acceleration. BUUUT maybe this only the rotational mass that is directly on the engine (clutch and pullies)....so maybe if you lighten your flywheel 10lbs that would be the equivelent of shaving 40lbs off the car (I Don't know). Now I know that will not help handling as much as taking it from the car. But everything helps my rather portly MINI. I just put the car on the scale (YEAH it was hard to get it on my wifes bathroom scale ) But I walked away scratching my head...2628lbs (with a quarter of a tank). I wanted to get under the 2600 mark. SO now I guess I will rip out the Sunroof who needs it anyway it never rains in SUNNY SO CAL
But I dont have the muffler on yet and that will save me 20lbs.
) But I walked away scratching my head...2628lbs (with a quarter of a tank). I wanted to get under the 2600 mark. SO now I guess I will rip out the Sunroof who needs it anyway it never rains in SUNNY SO CAL But I dont have the muffler on yet and that will save me 20lbs.
I did the math and....
Originally Posted by cristo
If you do the physics, it turns out 1# taken off the wheel is somewhere
between 1# and 2# taken off the chassis in terms of increasing
acceleration performance. Typically about 1.7#.
1# if all the weight of the wheel/tire is taken off at the center (axle),
and 2# if all the weight is taken off at the tread.
Of course weight taken off the wheel/tire helps reduce unsprung weight and
will help handling. (the suspension has less inertia to overcome moving up and down
over bumps, compressing and extending). Here it doesn't matter whether the weight reduction
is at the center or circumference or in between.
between 1# and 2# taken off the chassis in terms of increasing
acceleration performance. Typically about 1.7#.
1# if all the weight of the wheel/tire is taken off at the center (axle),
and 2# if all the weight is taken off at the tread.
Of course weight taken off the wheel/tire helps reduce unsprung weight and
will help handling. (the suspension has less inertia to overcome moving up and down
over bumps, compressing and extending). Here it doesn't matter whether the weight reduction
is at the center or circumference or in between.
for this case, it came out at 1.61
Originally Posted by sright
I read somewhere that taking a pound off of rotational mass equaled 4 lbs of sprung weight in acceleration. BUUUT maybe this only the rotational mass that is directly on the engine (clutch and pullies)
Matt
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