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      10-20-2008, 11:55 AM   #23
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Originally Posted by pittsy View Post
P40s are a little overplayed now on the e92s
they are just over played on the forums.
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      10-20-2008, 01:14 PM   #24
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they are just over played on the forums.
Yea sure, but they are still very nice, light weight, very strong and well balanced.
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      10-20-2008, 01:29 PM   #25
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Originally Posted by BMW-M-Mexico View Post
Yea sure, but they are still very nice, light weight, very strong and well balanced.
i know i love the rims! but his comment seemed like he was saying that too many people have them in general and i was just saying thats only on the forum. personally i would love to see these everyday haha.
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      10-22-2008, 06:23 AM   #26
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Originally Posted by Bob@BPS View Post
Not 7 pounds, but 7 times the weight because it is a rotating mass. That is the common factor used by most people. I'm not an engineer, so before I go spewing hearsay, I thought I'd do a little research. What I found was factors quoted as high as 10 times or as low as 2. What appears to be the truth is the farther the mass is from the axis of rotation, the more affect it will have. I interpret that to mean the actual factor will depend where the weight is saved. Tires should theoretically make a bigger difference than the wheels. What that would also mean is those REALLY expensive Dynamag wheels with CF spokes would make a bigger difference in unsprung weight than rotational mass, since they are saving most of the weight close to the axis of rotation.

Here are a few links I found during my Google search on "rotational mass":

http://news.carjunky.com/automotive/...nal_Mass.shtml
http://www.ux1.eiu.edu/~cfadd/1150/09Rot/RotDyn.html

Here is a good page that explains the difference between sprung and unsprung weight.

http://victorylibrary.com/mopar/sprung-c.htm

I also found a really good post at BimmerForums from 2003 here. The member StevenGee calculated a 0-60 difference of 2/10's of a second comparing a 36# wheel/tire combo to a 49# set on an E36 M3.

The bottom line is a lighter wheel/tire combo is definitely a performance mod. Another spec that is thrown around a lot is every 100 pounds of weight saved is equivalent to 10HP. Whatever the correct calc is, no one wil argue that weight is an enemy of performance (both speed and handling).

Bob
whoa. . .and I was going to buy them just for the cosmetic appeal. But gaining 10HP (Im guessing 172M Rims vs. HRE P40s) is definitely an added bonus.

Q. Are there any reps of the HRE P40s? I guess I never asked that question. (Thanks for the price quote, also).
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      10-22-2008, 01:09 PM   #27
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Originally Posted by PLAYON View Post
bump. if anyone has anymore opinions or prices
I personally like that design. They would look good on the E9x. PM me if you would like a quote on the HRE wheels.

An alternative is the Velocity Motoring V-710 wheels.
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      10-22-2008, 01:24 PM   #28
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Quote:
Originally Posted by Bob@BPS View Post
Not 7 pounds, but 7 times the weight because it is a rotating mass. That is the common factor used by most people. I'm not an engineer, so before I go spewing hearsay, I thought I'd do a little research. What I found was factors quoted as high as 10 times or as low as 2. What appears to be the truth is the farther the mass is from the axis of rotation, the more affect it will have. I interpret that to mean the actual factor will depend where the weight is saved. Tires should theoretically make a bigger difference than the wheels. What that would also mean is those REALLY expensive Dynamag wheels with CF spokes would make a bigger difference in unsprung weight than rotational mass, since they are saving most of the weight close to the axis of rotation.

Here are a few links I found during my Google search on "rotational mass":

http://news.carjunky.com/automotive/...nal_Mass.shtml
http://www.ux1.eiu.edu/~cfadd/1150/09Rot/RotDyn.html

Here is a good page that explains the difference between sprung and unsprung weight.

http://victorylibrary.com/mopar/sprung-c.htm

I also found a really good post at BimmerForums from 2003 here. The member StevenGee calculated a 0-60 difference of 2/10's of a second comparing a 36# wheel/tire combo to a 49# set on an E36 M3.

The bottom line is a lighter wheel/tire combo is definitely a performance mod. Another spec that is thrown around a lot is every 100 pounds of weight saved is equivalent to 10HP. Whatever the correct calc is, no one wil argue that weight is an enemy of performance (both speed and handling).

Bob
All good points, lightening the rotational mass will improve not only acceleration, but handling and braking as well.

Also factor in tire weights in the final decision - especially since they are the furthest away from centerline. I've seen many users get the lightest wheel on the market and run an cheap/inferior or heavy tire because they haven't done the research or ran out of their budget.
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      10-22-2008, 05:06 PM   #29
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Quote:
Originally Posted by PLAYON View Post
whoa. . .and I was going to buy them just for the cosmetic appeal. But gaining 10HP (Im guessing 172M Rims vs. HRE P40s) is definitely an added bonus.

Q. Are there any reps of the HRE P40s? I guess I never asked that question. (Thanks for the price quote, also).
well..the vmr v710 are the closest reps to the p40's..but big difference in weight..you can get them from eas,jlevisw or supremepower and all the other vendors that carry vmr items..i will pm you a price i got from a vendor on forums ok..
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      10-22-2008, 05:32 PM   #30
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Originally Posted by drZ View Post
well..the vmr v710 are the closest reps to the p40's..but big difference in weight..you can get them from eas,jlevisw or supremepower and all the other vendors that carry vmr items..i will pm you a price i got from a vendor on forums ok..
thanks drZ, PM replied. . .anyone else?
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      10-23-2008, 10:50 AM   #31
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PLAYON, PM Sent

Here are just a few pictures of a few M5's we have recently done on HRE P40's...

Please feel free to contact me if you have any further questions or would like to place an order

M5 on 20" HRE P40's (Textured Black)




Another M5 on 19" HRE P40's (Charcoal finish)


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      10-23-2008, 01:33 PM   #32
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Nice, but a little too "thick" for me. I dig the 19" CSL Style that EAS sells for only $900.
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Last edited by SpencerM3; 10-23-2008 at 05:07 PM.
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