Are their any drag nuts or overall car gurus here that can explain to me how much of a diffrence lighter rims and tires would make on a HHR? A friend was explaining how "sprung and unsprung weight" affects a cars performance, and it made me wonder about my car.
My question is would it really matter as much on a FWD car, or really even a car that isn't taken to the track every weekened?

 

Sprung weight is above the springs( body frame seats driver etc etc)..unsprung is the weight below the springs( EX wheels tires )the light the unsprung weight the faster the suspension can recover from road irregularities...put a 20lb barbell in your hand and shove it straight up in the air and then try to stop it....now try it with a 5lb bar....this is the same force your suspension sees everyday from those heavy wheels and tires...the lighter the better but it has its costs....light rims tend to deflect and bend easier, you don't hit pot holes with em. Race cars take this to extremes and those parts should stay on the race track..you can find lighter parts that wil hold up to everyday use and not need weekly maintenance, but its not practicle for a daily driver, especially if you live in an area that has bad roads....the tires needed are not street worthy as they are thin walled. Most people have 2 sets of rubber for this purpose...one for track and one for street.

 

Lighter wheels will improve handling by reduction of unsprung weight. The "power gain" from lightening the wheels, is somewhat overblown, and depends on what kind of dyno you're using. At the track, drag wheels can shorten ET's slightly in an-all out max-effort car, but aren't going to do much for the other 95%. Most people with drag wheels and skinnies do it because they think it looks cool.

 

If you hell bent on lighter rims, one should strongly consider buying forged aluminum wheels for added strength. Forged rims generally have about a 20 percent higher strength-to-weight ratio compared to cast or machined wheel of the same material.

 

Alright, thanks for the help. I was just looking at the price of some light weight wheels and I dont have the 1200+ I'd be willing to spend on only rims, let alone some rubber after that.

 

Lighter wheels will yield more gains than just the same unsprung weight savings. Rotational weight is not a linear effect. Someone on here weighed the stock SS wheels, and they came in at about 24lbs, if I remember correctly