OT: heavy vs light rim test

[austrian type-R]

I know a little ot, but interessting

Testobject: Audi S3, 265HP AWD

Mods: Chiptuning, removed back seats, Waterspraying on intercooler

Testtracks: 3 different roads driven 3 times back and thru, for best measurements.

1st test: Simas Extremo rims in 8.5 und 10x18 with 265/35/18 ca. 59 lbs per rim/tire combo.
0 - 60 mpH ~ always 6.5 seconds and 1/4 mile ca. 14.5 Seconds @ 97 mph

2nd test: OZ Superleggera with 225/45/17 ca. 38.5 lbs per rim/tire combo.
0 - 60 mpH ~ always 5.5 seconds and 1/4 mile ca. 13.9 seconds @ 102 mph

This was measured with Gmeter, is'nt that a HUGE difference. Hell, I don't undertand why people buy heavy rims!

[BoostedEX]

I could tell a HUGE difference in acceleration when I switched from my 14" stock steel rims 18-19 lbs each to my 15" Rota Slipstreams 11.8 lbs a piece [img]biggrin.gif[/img]

[-TJ]

Yeah, tire weight makes a diff. too, of course.
I just put my 15" Rota C8's w/newish 195/50-15's on my CRX. In the process, I weighed my 1990 OE 14" CRX stuff with equally newish 185/60-14's.

Both wheel tire combo's weighed 34.5 lbs. Just for comparison, I weighed a 14" steelie with a totally bald 185/60-14 on it. 37lbs.

[zip]

Your preaching to the choir!


I wish these were lighter than 9lbs. [img]wink.gif[/img]




<font color="#a62a2a" size="1">[ July 08, 2002 11:58 PM: Message edited by: zip ]</font>

[klintman]

its not just weight . its also how far that weight is massed from the center of the wheel . a 17in rim @20lb will have more mass further from the centerline then a 15in rim @20lb . even with the weight the same the 15in rim would still accelerate faster .

if you spin in an office chair that can rotate 360deg youll observe that the rpm decrease as your legs are extended . the same amount of force is at work with the same amount of weight , but the centerline of mass moved out from the central axis of the chair . the centerline of mass will always travel at the same speed with a given amount of force . when its moved outward its not slowing down , but actually traveling the same speed and distance just farther away from the axis making the rpm slower . the same basic priciples apply to da wheels , da tires , and all of your rotating parts .

not worded well ...sorry .

[AMslp_late]

<BLOCKQUOTE><font size=2 face="Verdana, Helvetica, sans-serif">quote:</font><table border="0" width="90%" bgcolor="#333333" cellspacing="1" cellpadding="0"><tr><td width="100%"><table border="0" width="100%" cellspacing="0" cellpadding="2" bgcolor="#FF9900"><tr><td width="100%" bgcolor="#DDDDDD"><font size=2 face="Verdana, Helvetica, sans-serif">Originally posted by klintman:


if you spin in an office chair that can rotate 360deg youll observe that the rpm decrease as your legs are extended . the same amount of force is at work with the same amount of weight , but the centerline of mass moved out from the central axis of the chair . the centerline of mass will always travel at the same speed with a given amount of force . when its moved outward its not slowing down , but actually traveling the same speed and distance just farther away from the axis making the rpm slower . the same basic priciples apply to da wheels , da tires , and all of your rotating parts .

</font></td></tr></table></td></tr></table></BLOCKQUOTE>


Actually I enjoyed that explanation. I understood what was going on but I never put words to it.

[JRCivic]

ZIP, you GO boy !!!

[Marc]

Nice choice, Zip. Those are the exact rims I had on my civic before it was stolen. 15x7 Volk Racing TE37 rims weigh exactly 9lbs.

Nowadays, I roll on *bling bling* chrome 17x8.5 3000GT rims. Not as heavy as you might think but I'm sure I'd see a huge difference by switching over to lightweight rims. The racers drool over the lightweight alloys and the hoochies dig the chrome. Now you see why I roll on these "heavy" chrome rims? [img]wink.gif[/img]

[acuraboy]

BoostedEX: How do you like your slipstreams?
Are they ok for everyday drivng? I heard it's
only recommend for racing. Planning to purchase
but not sure whether to get a 15" or a 16".

[BoostedEX]

Acuraboy, I love the Slipstreams [img]biggrin.gif[/img] I have not had ANY problems with them on the street <knock on wood>

Now that I look back I should have got the 16"