Effects of Wheel Size/Weight on Performance - Page 3 - Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum
User Tag List

Reply
 
LinkBack Thread Tools
post #21 of 26 (permalink) Old 04-01-2008, 11:08 PM Thread Starter
Registered User
 
crossbow's Avatar
 
Join Date: May 2003
Location: USA
Posts: 11,748
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 5 Post(s)
Thanks: 1
Thanked 14 Times in 9 Posts
Groans: 0
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Just to let peeps know. I just updated and cleaned up all of those links. If you see any more dead ones, send me a pm. I was spreading around some love on the 3 forums, so figured I should update it here as well. Also added a few new ones...shame on the 6tech ones, that forum is difficult to search now.





To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
crossbow is offline  
Sponsored Links
Advertisement
 
post #22 of 26 (permalink) Old 04-01-2008, 11:30 PM
Registered User
 
Argento's Avatar
 
Join Date: Jan 2005
Location: La Quinta, California
Posts: 606
Mentioned: 2 Post(s)
Tagged: 0 Thread(s)
Quoted: 6 Post(s)
Thanks: 24
Thanked 3 Times in 2 Posts
Groans: 1
Groaned at 1 Time in 1 Post
iTrader: 0 reviews
Thank you for doing this, Crossbow! Mad props!

(Traded-in)04Mazda6sSilverBlackLeatherShavedEmblemsMSSprin gsBilsteinHDMS ShifterMSCAIAEMAirStraightenerPowerStopK2449MeganR acingSTBMS6 TailsCordovaMotorSportsTBLightweightFlywheelRacing BeatAxle-BacksCorksportExhaustHangersYokohamaYK580(225/45r17)MB Interlines(48mm)LED'sXtec4000KH3'sSilverstarfronts ignalbulbsPIAAMirrorOrangerearsignalTintCargoNetSu rnoofMazdaMP3BoseZainoRepairedHeadlinerCP-E(Pink60Duro)

15 Mazda 6i Touring MTX/Cargo Net/Tint/Clear Bra
Argento is offline  
post #23 of 26 (permalink) Old 05-02-2008, 12:47 AM
Registered User
 
Join Date: Jan 2005
Location: Delaware
Posts: 2,883
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Thanks: 19
Thanked 108 Times in 89 Posts
Groans: 5
Groaned at 8 Times in 6 Posts
iTrader: 0 reviews
lots of good links, but how about some bottom line results: Audiworld had a good derivation regarding acceleration: http://www.audiworld.com/tech/wheel13.shtml


Assume you have oem 17"rim/215 tires at about 44 lbs each. You find new tire/rim set of 4 with exact same rolling radius, but 10 lbs lighter per corner. They have less static weight, and less rotating weight.

AT BEST, if all the weight loss was using magic foam rubber at the tire OD, then per corner, you save 10 lbs static weight and 10 lbs rotating weight (with an implied factor of static + inertia of 2.0). This means, assuming same road interface efficency, new setup will run as if you dropped 2.0 x 10 = 20 lbs off each corner, or 80 lbs off the total scale car weight, for a set of tires/wheels that is 40 lbs lighter.

The 2.0 inertia factor is an extreme limit. A more accurate average factor is 1.7 or so. So dropping 10 lbs at tire/wheel per corner has a net effect of dropping 17 lbs per corner, including inertia effect..

04 6S atx hatch
93 RX-7, 75 Trident
KevinK2 is offline  
Sponsored Links
Advertisement
 
post #24 of 26 (permalink) Old 08-26-2008, 02:50 AM
Registered User
 
Toadster's Avatar
 
Join Date: Sep 2003
Location: Folsom, CA USA
Posts: 1,160
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 12
Thanked 2 Times in 2 Posts
Groans: 1
Groaned at 0 Times in 0 Posts
iTrader: 0 reviews
this was a really good writeup on the mechanics/physics...

The effects of wheel weights will be different depending upon the type of driving. For skidpad and racetrack performance, you won't notice too much of a difference between light & heavy wheels. But try some canyon carving up Mulholland (Malibu) or Old San Marcos (S.B.) and you will definitely see an obvious difference. Wheels & tires are unsprung weight, meaning they aren't controlled by the suspension and will follow the contours of the road.

When you hit a 6" bump, that wheel & tire will move up 6". The energy this imparts through the suspension into the body will depend upon the mass of the wheels & tires. A 55-lb combo will hit the body harder and launch it off the bump more than a 40-lb wheel & tire. The more energy pushing up on the body, the higher it will move the body and the more the body will pull on the suspension as it launches off the back side of the bump, lossing traction momentarily.

Similar thing when you drive over a drop. Gravity will pull the wheel down with a fixed force. The springs then pushes down another amount based upon the spring rate. A heavier wheel & tire will get pushed down slower with the same spring-rate. Thus there's more 'hang' time over the bump, meaning you have wait longer to regain traction. This longer drop time also causes the body of the car to fall more into the hole than with a ligher wheel. Dropping more into the hole also means a bigger launch coming out of it.

So overall, on bumpy terrain, light wheels & tires allow the suspension to keep the body more level with a constant load on all the tires for best grip. Heavier wheels & tires tend to make the body bounce around more over the same terrain and this jostling causes uneven load on the tires and gives less grip.

The unsprung weigh of the rear axle comes into play here as well. Take a rough, bumpy mountain road all out with a solid rear axle. Then try it again at the same speed with an IRS rear end and you'll notice a dramatic improvement in cornering and drive traction.

SOLD 2004 Performance White MAZDA6s MTX
Injen CAI | Magnaflow Catback | CP-E MAF-c | 18% Tint | Red Line MT-90

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

17x7 Kosei T1 TS Wheels & Continental ContiExtreme Contact DWS 225/45-17

To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
|
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Toadster is offline  
post #25 of 26 (permalink) Old 09-15-2008, 11:05 PM
Registered User
 
Join Date: Jan 2005
Location: Delaware
Posts: 2,883
Mentioned: 10 Post(s)
Tagged: 0 Thread(s)
Quoted: 145 Post(s)
Thanks: 19
Thanked 108 Times in 89 Posts
Groans: 5
Groaned at 8 Times in 6 Posts
iTrader: 0 reviews
QUOTE (Toadster @ Aug 26 2008, 02:50 AM)
Quote:
this was a really good writeup on the mechanics/physics...

.... So overall, on bumpy terrain, light wheels & tires allow the suspension to keep the body more level with a constant load on all the tires for best grip. Heavier wheels & tires tend to make the body bounce around more over the same terrain and this jostling causes uneven load on the tires and gives less grip.

The unsprung weigh of the rear axle comes into play here as well. Take a rough, bumpy mountain road all out with a solid rear axle. Then try it again at the same speed with an IRS rear end and you'll notice a dramatic improvement in cornering and drive traction.
[/b]
Yup. Main benefit of light wheels and tires is handling and smooth ride, not 0-60 times.

04 6S atx hatch
93 RX-7, 75 Trident
KevinK2 is offline  
post #26 of 26 (permalink) Old 11-01-2009, 07:46 PM
Registered User
 
Join Date: Oct 2009
Location: NorCal by way of TX
Posts: 97
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Thanks: 0
Thanked 0 Times in 0 Posts
Groans: 0
Groaned at 0 Times in 0 Posts
iTrader: 0 reviews
QUOTE (Hoosteen @ Feb 5 2005, 05:29 PM)
Quote:




Now THAT was an entertaining AND educational lesson[/b]

it doesnt even have a gascap for saving that extra .0000007 lbs!


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

2006 sedan in P31
Looking for: some affordable springs (megan racing?), 18 or 19" wheels (7 spokes or less), CF eyelids, CF splitters, color matching low-profile front and rear bumper.
mandrew is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mazda 6 Forums : Mazda 6 Forum / Mazda Atenza Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome