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I don't understand why people worry about the weight of the rims because 90+% don't ever race there car. They stress out about finding the weight of the wheels then deciding what wheel they want from there limited choices. Can someone help me understand. I just bought a set of 19" wheels Konig Verdicts that weight alot more than stock and i cant even tell the difference in power or get up and go. Unless you have your car completely gutted with nothing more than a racing seat for the driver and thats it why worry about 30 - 40lbs extra. I am just trying to understand.
It's not JUST the wheels. People interested in losing weight don't just get lighter tires and say that's it. They try and lose weight all around the car, including the wheels. After a few lighter parts, it can really add up.
Posted By: spd33 Re: Why people worry about the weight of rims - 10/24/03 07:51 PM
Go back to 15's or 16's and you'll see why people worry about weight. It is hard to tell a diff when you up-size but you will assuredly notice if you go back down.

It is not only acceleration that is effected but deceleration as well.
What did you start with? If you go from 21-25lbs. stock rims to 25-30lbs. aftermarket you're not going to notice a huge difference, but I guarantee if you slapped on some 15lbs. forged wheels, you would be able to tell.
I'm on my 6th set of wheels of various sizes.

Most recenlty I went from 25lb+ 18" wheels to 15lb wheels.

The first time I took the car out, I was able to spin the wheels in 2nd with no problems whatsoever - which took effort with the 18s.

Pickup/acceleration was dramatically improved. Reducing weight in the car is one thing, reducing unsprung weight seems to be much more dramatic.
I forgot the exact formula but for every pound of weight taken off a corner its roughly equivalent to if you were to remove 65-85 pounds of total weight from the car.

ie you start with a 3500 car with 25 pound 17's then you drop 5 pounds each wheel to 20. That is roughly like reducing the weight of your car 65*5 = by 325 pounds! I can look up the formula and its probably all over the web but its the centrifugal forces that do some damage. Lighter wheels also are easier to slow down as well. So in a nutshell light wheels increase performance, make the car feel lighter, and its a braking mod as well. That is what all the hype is about.
Originally posted by Sitin on 19's:
I just bought a set of 19" wheels Konig Verdicts that weight alot more than stock and i cant even tell the difference in power or get up and go.




I consider myself pretty hamfisted when it comes to diagnosing changes in my car's handling, acceleration, and overall performance, and yet the difference was night and day between my stock 15" and the 4lb heavier 16" I originally put on the car. And that was not a race situation with a gutted car. Going from stock to 4 lb lighter wheels was like heaven.

Weight matters. Every pound shaved from total weight is worth more than the last, unlike hp, which is expensive and offers diminishing returns. Rotating weight, throughout the drivetrain, is worth, oh heck, 6-10 times more than static weight. Unsprung, rotating weight (wheels and suspension), affects handling, as well as acceleration and braking.

And no, it's not just for the race track. It's the difference between a plodding, heavy-feeling blvd cruiser, and a nimble, athletic sports sedan. It's a difference even I can feel.
I don't get it either...anyone wanna buy these 15lb wheels I've got so I can go and get some "bling" on the car...I'm just kidding of course.

People go with lightweight wheels because dropping rotational mass is a huge acceleration improver. Supposedly for every pound of rotational mass lost equals approximately 8lbs. of dead weight.

My wheel/tire combo weighed 6 lbs less per corner. So for each corner I dropped 48lbs "theoretically".

There is a tradeoff when going with a larger lighter wheel as the mass is spread further from center.

Optimal package would be the same diameter wheel/tire but less weight.
I am kind of starting understand but tell me this. How many of you have subwoofers in your trunk. Or how many of you are on the heavier side weight wise ( i am not being rude just trying to get a better grip on it)
its all about that performance...

take a set of 12.5lbs 15" wheels against your 19s...u better believe there will be a huge difference.

But if you don't care too much for performance it wouldn't bother you, or the average person for that matter.

you might benefit from bigger wheels by having a wider tire but if your wheels weigh more than stock ur killin ur performance overall...

And yea having subs in the trunk wouldn't make much sense if you were worried about rim weight
It's a trade off that I can't fully explain and don't completely understand.

SVT #1
15 lb wheels
stereo in rear

vs

SVT #2
25 lb wheels
no stereo

Stock wheels = 20 lbs (for arguements sake)

According to wavrdr's formula of:
1 lb of rotational mass lost equals approximately 8lbs of dead weight

SVT #1 lost 160 lbs of dead weight over stock
SVT #2 added 160 lbs of dead weight

SVT #1 = -160 lbs over stock
SVT #2 = +160 lbs over stock

Throw in a stereo for SVT #1 that weighs 100lbs.

SVT #1 = -60 lbs over stock
SVT #2 = +160 lbs over stock

Plus, SVT #1 should accelerate faster and handle better assuming equal driver.

That's the best I could do.
Posted By: low10s Re: Why people worry about the weight of rims - 10/25/03 12:54 AM
it is not the same, but when i changed sprockets on my R1 i lost about 6 LB. the turn in feel of the bike was like night and day. again rotating mass was reduced. the same with a car, with less weight at the corners the steering should be more responsive, and give an overall better feel of what the car is doing. yes quicker acceleration is a plus, but to me it is the total feel of the car. by the way i am looking at the slipstreems by Rota on zxtuner. com.
anyone seen these on a contour. thanks
If you had an ATX zetec, you'd understand. The acceleration is vastly slower and top speed before a lotta my engine mods was 115mph, now with more mods but heavier tires, it's 110mph. It's noticeable for sure, just not everyone is into their car as some of us are. I would love some lightweight 15"s.
Originally posted by Sitin on 19's:
I am kind of starting understand but tell me this. How many of you have subwoofers in your trunk. Or how many of you are on the heavier side weight wise ( i am not being rude just trying to get a better grip on it)



No subs, and temporarily no back seat. And got some other weight lightening things going on. Every little bit helps though the little things aren't really noticeable unless you do them all at once.
cant wait to get my new wheels only 16.5 lbs each
Posted By: Pigeon Re: Why people worry about the weight of rims - 10/26/03 05:42 AM
It's not so much for acceleration (though there is some effect) as it is for handling. Wheels = unsprung weight = what the suspension pieces have to control the motion of. Less weight = more precise control = better handling and ride. Simple.

I definitely noticed the difference from 22# stock steel wheels to 14# forged BBS alloys (also stock items, though limited production) on my old Miata.

Scott
Originally posted by Pigeon:
It's not so much for acceleration (though there is some effect) as it is for handling.




I guess it depends on what your focus is, but the beauty of light wheels is that they have such an impact, really, on 3 things:

1. Handling (via reduction in unsprung weight)
2. Acceleration (via reduction of rotating mass in the driveline)
and
3. Looks.

And to answer another question, no big noise generators anywhere, but if I did, I'd have all the more reason to improve performance elsewhere. And, I shaved a good 20 lbs out from behind the steering wheel last year. Can't feel the difference in the car, but I sure feel better.

(Reminds me of road cyclists that spend $$$ on the latest unobtanium shift-lever to shave 20 grams off the bike, but "really need to lose about 20 lbs" to get to their "optimum weight.")
No airbag? I'm gonna do that soon too I think, don't need it with a harness.
Less unsprung weight for better handling as mentioned before and less rotational mass (also mentioned before, but mostly negligible). One thing to keep in mind is, if you get a lighter rim that is wider, chances are you will be going with a wider tire that will be heavier then the ones before and may negate some if not all the weight savings.

Henry
Originally posted by Kremithefrog:
No airbag? I'm gonna do that soon too I think, don't need it with a harness.




Airbag is intact. Driver "shaved and heat-cycled."
Learn the difference between sprung weight and unsprung weight, and then come back to us.
Originally posted by RogerB:
Originally posted by Kremithefrog:
No airbag? I'm gonna do that soon too I think, don't need it with a harness.




Airbag is intact. Driver "shaved and heat-cycled."




LOL, aight. Down know if I can stand to lose any of my 130lbs.
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