How much RWHP do those "heavy" wheels rob? Answers inside fresh from the dyno!
03-08-2006, 11:42 PM
#61
Instructor
Member Since: Jun 2004
Posts: 112
Likes: 0
Received 0 Likes
on
0 Posts
Alan,
I give you credit for taking the time and expense of doing this test and posting your results. Sorry but I question your conclusions since you introduced two variables (size and weight) and I don't know how one could tell the overall effect each had on your results.
I think everyone believes that lighter is better (faster) but I don't think you can tell how much better using this data. This is just my opinion and you know how that old saying goes.
Hope you have the chance sometime to rerun the test and compare wheel/tires of the same size. Would be interested in the results.
I give you credit for taking the time and expense of doing this test and posting your results. Sorry but I question your conclusions since you introduced two variables (size and weight) and I don't know how one could tell the overall effect each had on your results.
I think everyone believes that lighter is better (faster) but I don't think you can tell how much better using this data. This is just my opinion and you know how that old saying goes.
Hope you have the chance sometime to rerun the test and compare wheel/tires of the same size. Would be interested in the results.
03-09-2006, 07:43 AM
#62
Melting Slicks
Member Since: Sep 2003
Location: Augusta GA
Posts: 2,911
Likes: 0
Received 1 Like
on
1 Post
St. Jude Donor '05-'06
Ok I had to do it... just weighed the 18 x 12 CCW streets, with centercaps, Mich PS 335 30s.... 55.8 lbs
OEM Z fronts 17 x 9.5 and MT ET St radials 275 40s... 44.4 lbs
When putting OEM 10.5 Z rears on the car yesterday, they are shorter than the CCWs and I suspect very cloe in weight to the MTs. I will have dyno numbers soon to see the delta.
Bluff,
bigger wider tires do give a RWHP drop
Dave
OEM Z fronts 17 x 9.5 and MT ET St radials 275 40s... 44.4 lbs
When putting OEM 10.5 Z rears on the car yesterday, they are shorter than the CCWs and I suspect very cloe in weight to the MTs. I will have dyno numbers soon to see the delta.
Bluff,
bigger wider tires do give a RWHP dropDave
03-09-2006, 10:09 AM
#63
Le Mans Master
Originally Posted by cor99vette
Please read:
http://forums.corvetteforum.com/showthread.php?t=1118172&forum_id=109
Answer the question asked by the thread creator with personal experience or fact, and keep the attitudes and sarcasm out of the thread...
http://forums.corvetteforum.com/showthread.php?t=1118172&forum_id=109
Answer the question asked by the thread creator with personal experience or fact, and keep the attitudes and sarcasm out of the thread...
04-22-2006, 11:32 AM
#64
Safety Car
Originally Posted by Wicked Weasel
Here are the weights
Wheels
19.2 lbs, front; 21.4 lbs, rear - 97-99 OEM wagon - Src
22 lbs, front; 29 lbs, rear - 97-99 OEM wagon - Src
17 lbs, front; 19.5 lbs rear - 97-00 OEM magnesium - Src
17.5 lbs, front; 19.5 lbs, rear - 97-00 OEM magnesium - Src
18.08 lbs, front; 20.06 rear - 00 OEM standard, thin spoke, high polish - Src
17 lbs, front; 20 lbs, rear - 00 OEM standard, thin spoke, painted, no sensors or centercaps - Src
16 lbs, front; 20 lbs, rear - 01 OEM standard high polish - Src
19.6 lbs, front; 21.4 lbs, rear - 01 Z06 forged - Src
19.2 lbs, front; 21 lbs, rear - 02-04 Z06 cast/spun - Src, Src
24 lbs, 18x10.5 - 00+ repro high polish - Src
28 lbs, front; 32 lbs, rear - Z06 chrome repro - Src
23 lbs, front; 26 lbs, rear - Z06 chrome repro - Src
23.5 lbs, front; 24.5 lbs, rear - Z06 Motorsports, polished - Src
20 lbs, 17x8.5, 58mm offset, front; 23 lbs, 18x9.5, 65mm offset, rear - PWO - Src
22 lbs, 18x10.5, 58mm offset, front - HRE 545 w/clear center - Src
27 lbs, 18x12, 74mm offset, rear - HRE 545 w/clear center - Src
24/25 lbs - Z07 wheel weight, front - Src
28 lbs - Z07 wheel weight, rear - Src
Wheels
19.2 lbs, front; 21.4 lbs, rear - 97-99 OEM wagon - Src
22 lbs, front; 29 lbs, rear - 97-99 OEM wagon - Src
17 lbs, front; 19.5 lbs rear - 97-00 OEM magnesium - Src
17.5 lbs, front; 19.5 lbs, rear - 97-00 OEM magnesium - Src
18.08 lbs, front; 20.06 rear - 00 OEM standard, thin spoke, high polish - Src
17 lbs, front; 20 lbs, rear - 00 OEM standard, thin spoke, painted, no sensors or centercaps - Src
16 lbs, front; 20 lbs, rear - 01 OEM standard high polish - Src
19.6 lbs, front; 21.4 lbs, rear - 01 Z06 forged - Src
19.2 lbs, front; 21 lbs, rear - 02-04 Z06 cast/spun - Src, Src
24 lbs, 18x10.5 - 00+ repro high polish - Src
28 lbs, front; 32 lbs, rear - Z06 chrome repro - Src
23 lbs, front; 26 lbs, rear - Z06 chrome repro - Src
23.5 lbs, front; 24.5 lbs, rear - Z06 Motorsports, polished - Src
20 lbs, 17x8.5, 58mm offset, front; 23 lbs, 18x9.5, 65mm offset, rear - PWO - Src
22 lbs, 18x10.5, 58mm offset, front - HRE 545 w/clear center - Src
27 lbs, 18x12, 74mm offset, rear - HRE 545 w/clear center - Src
24/25 lbs - Z07 wheel weight, front - Src
28 lbs - Z07 wheel weight, rear - Src
04-22-2006, 11:58 AM
#65
Instructor
Originally Posted by kbreese
One wheel missing from this chart is OEM chromed Z06 wheels. I am really curious how much weight the chroming adds to stock OEM Z06 wheels. I am wanting to purchase Chromed OEM Z06 wheels for the better overall quality of the wheel, but mostly to avoid the hefty weight of the chrome repro's. But I don't know what the actual weight difference is.
04-22-2006, 12:42 PM
#66
Safety Car
Originally Posted by IT L GO
Less than a pound per rim
04-22-2006, 01:49 PM
#67
Burning Brakes
Originally posted:
We dynoed Combo 1 first (Stock 17"). The best pull was 421 rwhp and 395 rwtq.
Next we dynoed Combo 2 (18" Z07). The best pull was 409 rwhp and 386 rwtq.
FYI, had this test been conducted with the same diameter tires (with no change to their test weights) the lost rwhp due to wheel weight differences would have been even greater. This is because the smaller tire diameter increased the effective gear ratio reducing the power that would have been produced had the diameters been the same. You can conclude from this that wheel weight has an even larger effect on lost power than this test exibited.
Good test.
Shirl Dickey
We dynoed Combo 1 first (Stock 17"). The best pull was 421 rwhp and 395 rwtq.
Next we dynoed Combo 2 (18" Z07). The best pull was 409 rwhp and 386 rwtq.
FYI, had this test been conducted with the same diameter tires (with no change to their test weights) the lost rwhp due to wheel weight differences would have been even greater. This is because the smaller tire diameter increased the effective gear ratio reducing the power that would have been produced had the diameters been the same. You can conclude from this that wheel weight has an even larger effect on lost power than this test exibited.
Good test.
Shirl Dickey
04-22-2006, 02:18 PM
#68
Le Mans Master
Originally Posted by kbreese
One wheel missing from this chart is OEM chromed Z06 wheels. I am really curious how much weight the chroming adds to stock OEM Z06 wheels. I am wanting to purchase Chromed OEM Z06 wheels for the better overall quality of the wheel, but mostly to avoid the hefty weight of the chrome repro's. But I don't know what the actual weight difference is.
04-22-2006, 02:41 PM
#69
Team Owner
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Posts: 43,084
Likes: 0
Received 24 Likes
on
24 Posts
So lets see:
More weight the less acceleration
Less weight the more acceleration
More weight further out from the center of rotation, less acceleration.
So we want light weight wheels with smaller diameter. That maybe one reason the T1 races use 17" wheels all around, they are faster.
Speaking of rotation weight, BBK rotors. The new C6 Z06 brake rotor is 25 lbs vs the stock brake rotor is 17 lbs
More weight the less acceleration
Less weight the more acceleration
More weight further out from the center of rotation, less acceleration.
So we want light weight wheels with smaller diameter. That maybe one reason the T1 races use 17" wheels all around, they are faster.
Speaking of rotation weight, BBK rotors. The new C6 Z06 brake rotor is 25 lbs vs the stock brake rotor is 17 lbs
04-22-2006, 02:47 PM
#70
Team Owner
Member Since: Sep 2003
Location: Raleigh / Rolesville NC
Posts: 43,084
Likes: 0
Received 24 Likes
on
24 Posts
Originally Posted by chiefDave
Ok I had to do it... just weighed the 18 x 12 CCW streets, with centercaps, Mich PS 335 30s.... 55.8 lbs
18 x 13 CCW ( Classic track) with Good Year G19 R470 18 x 25.5 x 11.5 = 39 lbs
04-22-2006, 05:52 PM
#72
Racer
Member Since: Jun 2004
Location: Brookfield WI
Posts: 433
Likes: 0
Received 0 Likes
on
0 Posts
Originally Posted by 6Speeder
Good post! It really shows the problem with adding rotating weight. Thank you, most folks won't go through the trouble to document this properly.
