Lightweight wheels
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Joined: Jan 2006
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Lightweight wheels
If you replace the standard 17's for lightweight wheels you can reduce unsprung mass. So for example, reduce the front wheels weight by 3KG and rears by 5KG that's 8KG, i read 1KG of unsprung is equivalent to 10KG of sprung mass so 80KGS! sprung mass!.
That's easily enough to make a difference of 0.1 in a 1/4mile of a mile.
I read however on tests they made little difference to acceleration but helping breaking and the suspension working.
What do folk think?
Initially you believe they will help acceleration but it appears not the more you look into it.
That's easily enough to make a difference of 0.1 in a 1/4mile of a mile.
I read however on tests they made little difference to acceleration but helping breaking and the suspension working.
What do folk think?
Initially you believe they will help acceleration but it appears not the more you look into it.
Joined: May 2012
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From: Leighton Buzzard
I think they make a huge difference and if I could lay my hands on some I would
I have always been a santabpod person taking mot cars I have owned there intact I have the fastest time for a standard zs 180 a striped stage 1 zs180 and a forced induction zs180'up the strip.
I had a car that ran a 14.3 with 200 bhp it was striped, I went back with a car that had 210 bhp but lightweight wheels and flywheel and I managed a 13.7 it really was amazing, the car was also striped but less so than the first.
Get some
I have always been a santabpod person taking mot cars I have owned there intact I have the fastest time for a standard zs 180 a striped stage 1 zs180 and a forced induction zs180'up the strip.
I had a car that ran a 14.3 with 200 bhp it was striped, I went back with a car that had 210 bhp but lightweight wheels and flywheel and I managed a 13.7 it really was amazing, the car was also striped but less so than the first.
Get some
Joined: Oct 2005
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From: Banbury, Oxfordshire
Unsprung mass is nothing to do with acceleration, but the less you have the better ride and handling you'll have. The acceleration comes from reducing the rotating mass, i.e. the wheels and tyres. But I find it hard to believe you'll notice 0.1 seconds over 1/4 mile in day to day driving.
What's lightweight? Lots of wheels say they're "lightweight", but obviously you need to look at the actual weight. And 17" wheels and tyres are heavier than 16s. So if you really care you'd fit 16s; maybe 15s if you could get them to fit. In fact if you really care, get much smaller brakes and see if you can fit 14s.
What's lightweight? Lots of wheels say they're "lightweight", but obviously you need to look at the actual weight. And 17" wheels and tyres are heavier than 16s. So if you really care you'd fit 16s; maybe 15s if you could get them to fit. In fact if you really care, get much smaller brakes and see if you can fit 14s.
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As i do not know the definition of unsprug mass (i am sorry 
) i will have to agree with Dembo. Rotating mass is very important on acceleration. Lighter wheels, tyres, brake discs etc will make a big difference on acceleration. You will notice more the difference on higher gears and speeds. Of course you have a S/C so i do not know if you will notice that difference although it will be. But on OEM cars the difference is more obvious. Some people here in Greece have the BBS OEM 16's wheels from the JDM model and believe me the difference is very obvious. I think i saw someone in UK forum selling those wheels but you are looking for 17's.
P.S. Even lighter engine pulleys will make a small difference in our car (another rotating mass) but there is a debate about bad harmonics that can be created in the engine as it is balanced with the OEM pulleys weight and i will have to agree. Another rotating mass is a the flywheel. A lighter one will help on acceleration in first gears but it will not help on higher speeds.
) i will have to agree with Dembo. Rotating mass is very important on acceleration. Lighter wheels, tyres, brake discs etc will make a big difference on acceleration. You will notice more the difference on higher gears and speeds. Of course you have a S/C so i do not know if you will notice that difference although it will be. But on OEM cars the difference is more obvious. Some people here in Greece have the BBS OEM 16's wheels from the JDM model and believe me the difference is very obvious. I think i saw someone in UK forum selling those wheels but you are looking for 17's. P.S. Even lighter engine pulleys will make a small difference in our car (another rotating mass) but there is a debate about bad harmonics that can be created in the engine as it is balanced with the OEM pulleys weight and i will have to agree. Another rotating mass is a the flywheel. A lighter one will help on acceleration in first gears but it will not help on higher speeds.
Thread Starter
Joined: Jan 2006
Posts: 20,788
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From: location, location
Just read this...
On an NSX
http://www.nsxprime.com/forum/showthread.php?p=917231
Looking for an excuse to change wheels
On an NSX
http://www.nsxprime.com/forum/showthread.php?p=917231
Looking for an excuse to change wheels
Joined: Mar 2001
Posts: 31,181
Likes: 58
From: Hertford
Sprung mass is everything bodily supportes by the roadsprings.
Unsprung weight isn't and basically consists of wishbones, uprights, hubs and roadwheels. It's weight because they move around on bumps and the bit at the polar end, the wheel, has a huge significance on the damping capabilities.
Lighter wheels affecting acceleration is one of those internet half-truths; the inertia of the wheel becomes momentum in the same direction, so the effect really is marginal. Bump & rebound is an oscillation, ergo the effect on tyre contact pressure and ride is most pronounced. Of course, offsetting the wheel farther out will increase the loading on the bearings & damper by increasing leverage length and thus counter-pruductive, so sometimes fitting lightweight wheels may a case of a little knowledge being dangerous!
It's all part of this big wheels>increased performance justification in the minds of the half-witted.
Unsprung weight isn't and basically consists of wishbones, uprights, hubs and roadwheels. It's weight because they move around on bumps and the bit at the polar end, the wheel, has a huge significance on the damping capabilities.
Lighter wheels affecting acceleration is one of those internet half-truths; the inertia of the wheel becomes momentum in the same direction, so the effect really is marginal. Bump & rebound is an oscillation, ergo the effect on tyre contact pressure and ride is most pronounced. Of course, offsetting the wheel farther out will increase the loading on the bearings & damper by increasing leverage length and thus counter-pruductive, so sometimes fitting lightweight wheels may a case of a little knowledge being dangerous!
It's all part of this big wheels>increased performance justification in the minds of the half-witted.
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Joined: Apr 2004
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From: Sunshine Coast - England UK
You won't see any race car fitting heavier wheels. There is no doubt that lighter wheels are a good thing, as outright weigh reduction. The multiplication factor of unsprung mass benefit is questionable for me.
As Nick is pointing out, once the mass is overcome (to me this should be considered as reduced torque required, from reduced mass) I suspect the benefits are less than people think.
As Nick is pointing out, once the mass is overcome (to me this should be considered as reduced torque required, from reduced mass) I suspect the benefits are less than people think.
Thread Starter
Joined: Jan 2006
Posts: 20,788
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From: location, location
You won't see any race car fitting heavier wheels. There is no doubt that lighter wheels are a good thing, as outright weigh reduction. The multiplication factor of unsprung mass benefit is questionable for me.
As Nick is pointing out, once the mass is overcome (to me this should be considered as reduced torque required, from reduced mass) I suspect the benefits are less than people think.
As Nick is pointing out, once the mass is overcome (to me this should be considered as reduced torque required, from reduced mass) I suspect the benefits are less than people think.