How much difference will -5lbs make?

[dradernh]

Originally Posted by Captain Snooze

No, only on the front.

Yes, the Essex Kits are indeed front-only kits. Thank you for the clarification.

Originally Posted by Captain Snooze

I am going into pedant mode.

Oh, okay. Thanks, again.

[Wayno]

The mechanical grip you gain (with 4 wheels) far, far outweighs the difference in acceleration (2 wheels).
Even the OEM 16" Enkei wheels are a handling upgrade over the 17" Subaru wheels.

1. 16x7 SSR Type C (so jealous)
2. 16x7 RH CP-035R
3. 16x7 Volk TE37 (the only ones you'll easily find second hand)

[ayau]

Just buy my 17x7.5 Rays CE28N instead. They weigh 13.8lbs. Best of both worlds.

http://www.ft86club.com/forums/showthread.php?t=44955

[Yui-Chan]

Originally Posted by Wayno

The mechanical grip you gain (with 4 wheels) far, far outweighs the difference in acceleration (2 wheels).
Even the OEM 16" Enkei wheels are a handling upgrade over the 17" Subaru wheels.

1. 16x7 SSR Type C (so jealous)
2. 16x7 RH CP-035R
3. 16x7 Volk TE37 (the only ones you'll easily find second hand)

Those SSRs are nice!

Anyone know the exact weight of 16" te37??

[Yui-Chan]

Can Enkei make custom wheels? Aren't the popular 17x9 +35 considered "custom" since it isn't listed as available in 5x100 on their spec sheet?

Man....16x7 5x100 in a custom low +19 offset (like the below pics) would look soooo sweeeet!!!

Please make these Enkei!! lol



14x7 +19 (but a 16x7 in the same +19 offset should be very similar in spoke depth, flatness and deep lip):

[Timmy_Jones]

You absolutely won't notice a thing, especially on the street. But it will make a slight performance difference.

[KonTheory]

I just went from stock setup to 17x9 enkei rpf1's which are said to weigh 15.9lbs each
And put on some Nitto NT05 235/40/17 on them,
I did not notice a damn thing in acceleration. but once you hit the twisties its the biggest difference...
If you want an acceleration boost, nothing has been as good as a tune (besides of course going FI)

[Yui-Chan]

Originally Posted by KonTheory

I just went from stock setup to 17x9 enkei rpf1's which are said to weigh 15.9lbs each
And put on some Nitto NT05 235/40/17 on them,
I did not notice a damn thing in acceleration. but once you hit the twisties its the biggest difference...
If you want an acceleration boost, nothing has been as good as a tune (besides of course going FI)

Of course you won't feel any weight reduction...once those 23-24lb Nittos are mounted, it'll be the same weight as the stock setup :P

Those RPF1 wheels are light.. but big sticky tires are heavy. Ooft!

[KonTheory]

Originally Posted by Yui-Chan

Of course you won't feel any weight reduction...once those 23-24lb Nittos are mounted, it'll be the same weight as the stock setup :P

Those RPF1 wheels are light.. but big sticky tires are heavy. Ooft!

You are right, I didnt have a scale around and wanted to weigh each setup so I will do that soon, but just picking up a stock wheel and tire, vs the enkei with nitto tire on it, the enkei + nitto was definitely lighter

[EAGLE5]

There is unsprung mass, rotating mass, and the locations of those masses.

Reducing unsprung mass helps with moving the suspension. When the weight is farther out, like with wider wheels or spacers, then the suspension has more work to do. Try holding a five pound weight to your chest then try holding it with your arms straight out. Theoretically, you would want a wheel with a structure as close to the hub as possible, and with a tire section that is as close in as possible while still meeting your front/rear track and clearance needs. Less weight can give better ride, better grip over bumps, and better overall handling. For acceleration purposes, losing unsprung mass is the same as losing any other mass. There is a slight downside of losing mass down low, where all unsprung mass should be. This raises your center of gravity, which theoretically can make the car less stable.

Less rotating mass helps mostly with acceleration and braking. The engine has less mass to spin. However, it takes more effort to lift a weight with your arms outstretched than it does to lift a weight close your body. A wheel can have its mass more towards the hub or more in the barrel. No wheel manufacturer has published any specs on this, at least not that I've seen. It's conceivable that a 20lbs wheel with a lot of weight on the hub could take less power to spin than a 15lbs wheel with most of its weight on the barrel. An 18x10 wheel that weighs 20lbs will likely have more weight on the barrel than a 17x7 wheel of the same weight. When you add in the weight of wide tires, weight shifts even more to the outside of the wheel.

With less mass to spin, the engine can work more easily, aiding acceleration. They can also slow down more quickly, aiding in braking. There are downsides to cutting rotational mass. Wheels have a gyroscopic effect that gives the car some stability. Less mass means less effect and less stability. It also means easier turning. So better on corners and worse on straights. One other disadvantage of losing rotating mass is that you lose heat sink mass for your brakes and tires. This could only matter at the track, where you're pushing your brakes and tires to the edge of what they can handle. Less rotating mass on the flywheel can also make shifting harder, or at least take time to get used to.

In the end, though, most of those downsides of cutting rotational and unsprung mass are not really noticeable. If you get a lighter wheel, tire, brake system, suspension, flywheel, clutch, and drive shaft, you will probably have a noticeably faster, more agile car that you just spent a shit load of money on. It will also still be a lot slower than a stock Vette and less agile than a Miata.

[Flow]

I went from stock wheel/tire to ~15lb wheel (17x8 tc105n) & ~22lb tire (225/17/45 PSS), so around a ~4lb total weight loss. The ride quality was definitely improved, and I saw ~.2mpg better fuel efficiency.

[Grateful Dave]

I noticed a 3lb reduction with my Enkei Fujins' 17x7.5 with stock tires. A 5lb reduction is even better.

[ZDan]

10:1 and 20:1 weight reduction equivalency are total fantasy. I've run the numbers and it's more like 1.9:1 for a tire, 1.4:1 for a wheel.

Given the same tires and the same wheel offset, I would bet that you wouldn't notice a 5 lb. lighter wheel doing blind back-to-back testing.

[Wayno]

People who say you won't notice a difference need more sensitive ass cheeks.

More often than not when you get lighter wheels you'll also get wider, stickier tyres with thicker sidewalls, so even though you still might have less mass overall (which still helps your suspension), it's distributed towards the outside of the wheel which negates the rotational aspect.

It's a shame the yanks don't get access to the 16" oem wheels. Same offset, and tyre width and weight but 2.2kg lighter wheel, which is immediately and undeniably noticeable.