Wheel weight and effects on WHP

[TGX4776]

I am wondering how much WHP is freed up with lighter wheels.

I am trying to decided between two different wheels one of which is 20 LBS each the other is 14.6 LBS each resulting in weight difference of 23.2 LBS. Which is a lot but I am wondering if the WHP gains is worth the extra $200 and sacrifices to styling.

the original wheels weigh in at about 25 LBS each i have heard.

Lightweight

http://www.tirerack.com/wheels/WheelClo ... ort=Weight (http://www.tirerack.com/wheels/WheelCloseUpServlet?target=runWheelSearch&initialPartNumber=TS125LG&wheelMake=Kosei&wheelModel=K1+TS&wheelFinish=Light+Grey+Painted&showRear=no&autoMake=Subaru&autoModel=Legacy+GT+Legacy+GT+Sedan&autoYear=1997&autoModClar=&filterSize=All&filterFinish=All&filterSpecial=false&filterBrand=All&filterNew=All&sort=Weight)

Style

http://www.tirerack.com/wheels/WheelClo ... ort=Weight (http://www.tirerack.com/wheels/WheelCloseUpServlet?target=runWheelSearch&initialPartNumber=4427708045GM&wheelMake=Enkei+Performance&wheelModel=EKM3&wheelFinish=Gunmetal+Painted&showRear=no&autoMake=Subaru&autoModel=Legacy+GT+Legacy+GT+Sedan&autoYear=1997&autoModClar=&filterSize=All&filterFinish=All&filterSpecial=false&filterBrand=All&filterNew=All&sort=Weight)

[chuckthefuk]

"Using the most basic of math formula's, if you just multiply your unsprung weight loss by 2, thats the roughest calculation of the static weight loss (so if you shaved 50 lbs of unsprung off...thats 0.1 seconds or 15 hp added in the 1/4). Some people argue for the 3x or 4x multiplier, as many studies have shown depending on the sizing involved, the actual benefit can be larger then just 2x."
Link -> http://www.rx8club.com/archive/index.php/t-42185.html

.. To sum it up.. The lighter the wheel the less power needed to turn it. In the N/A world of 120 WHP this wont make that much of a difference but in the 300+ WHP yes it makes a difference.

-Chuck

[TGX4776]

Ok thanks for the info. I will go for better looks.

[rougeben83]

Lighter wheels will affect a lot more than just acceleration in a car as everything gets translated through the tires. I went from 19.5lb MB weapons to 15.6lb RPF-1's (both 17x8 wheels, running 225/45 tires), and the car is more willing to change direction and smoothly accelerate, the ride seems to be a little more fluid as well. However keep in mind that weight is sacrificed in terms of strength and rigidity of the wheel so don't just base you decision on weight alone. How much you sacrifice is a crapshoot however, as superlight does not equate to super fragile. Some of the notable ones that tend to be lightweight but easy to bend are ssr's and o.z. wheels for example.

For me, I would get the lightest, strongest wheel I can afford in a design that I can stomach. I spend more time driving the car rather than looking at it :)

[TGX4776]

well not only are the 200 more expensive but they also are not the color I want so I would need to paint them back or get them powder coated. And I still am losing about 20LBS over the stock wheels.

[ouch1011]

The effects of gearing and rotational inertia is HUGE on underpowered cars like the na legacies are. But, the effects of changes in rotational inertia (wheel weight) are going to be most noticable when the acceleration force is the greatest, i.e. lower gears. So, in a 4th gear dyno pull, lightweiht wheels, flywheel, etc are not going to be as noticable as in 1st gear.

I noticed a big difference in switch from my heavy-ass 18s to my sti 17s regarding direction changes and steering feel, but not really in acceleration.