Heavier wheels = decrease in breaking/turning?
06-23-2008, 10:38 PM
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Heavier wheels = decrease in breaking/turning? Hey fellas I recently got rid of my TTII's 17-9.5/11 for a set of 10 spokes. For the entire length of time i had the TTII's, I noticed that the car would go into ABS fairly quickly. Now with the 10 spokes I hardly see ABS engagement on hard braking.
Also when in the canyons, I noticed the front end used to push (understeer). Always thought it was a suspension issue. Now that i have the 10 spokes it feels soooooo much more neutral and fluid through turns.
Could this be because i dropped about ~18 of rotating mass? I found the wheel weights and it comes out to about 14lbs for the rims alone and a lil more for the tires.
Has anyone else noticed this? Or am i just crazy?
Also when in the canyons, I noticed the front end used to push (understeer). Always thought it was a suspension issue. Now that i have the 10 spokes it feels soooooo much more neutral and fluid through turns.
Could this be because i dropped about ~18 of rotating mass? I found the wheel weights and it comes out to about 14lbs for the rims alone and a lil more for the tires.
Has anyone else noticed this? Or am i just crazy?
06-24-2008, 01:38 PM
#3
Rotational mass and unsprung weight has quite a large effect on braking, handling and acceleration, 60 ft times, less driveline stress etc etc.
Many people tend to overlook the benefits when they purchase inexpensive or heavy wheels. Some look at it and think "these are only 5 lbs more per wheel" then something else...problem is that the 5 lb difference between their wheel and a lighter one realistically converts to ~20lbs of static weight.
Take our drag wheels for example, compared to a set of prostars, using the prostars you're leaving ~50lbs of weight on your car which directly relates to performance. People tend to overlook they could have lost 50lbs of weight by using our wheels...the kicker is some feel since they purchased an economy heavier wheel; they have new money for other mods...so they go out and purchase a k-member for 500.00 and only save 35lbs. So what was really saved???
They would have been better off just purchasing lighter wheels for the performance.
To look at it in another perspective, look at the performance characteristics of an aluminum flywheel and a steel flywheel. How just a few lbs changes how the engine performs.
Many people tend to overlook the benefits when they purchase inexpensive or heavy wheels. Some look at it and think "these are only 5 lbs more per wheel" then something else...problem is that the 5 lb difference between their wheel and a lighter one realistically converts to ~20lbs of static weight.
Take our drag wheels for example, compared to a set of prostars, using the prostars you're leaving ~50lbs of weight on your car which directly relates to performance. People tend to overlook they could have lost 50lbs of weight by using our wheels...the kicker is some feel since they purchased an economy heavier wheel; they have new money for other mods...so they go out and purchase a k-member for 500.00 and only save 35lbs. So what was really saved???
They would have been better off just purchasing lighter wheels for the performance.
To look at it in another perspective, look at the performance characteristics of an aluminum flywheel and a steel flywheel. How just a few lbs changes how the engine performs.
06-24-2008, 03:50 PM
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VERY glad i was not imagining it. I heard something about rotating mass adding up to be ALOT more than the actual weight.
Hell for my Open Road Racing veture next year, i might even look into a lighter dedicated set. Anyone have any recommendations?
Hell for my Open Road Racing veture next year, i might even look into a lighter dedicated set. Anyone have any recommendations?
- I am happy somebody actually "gets it" when it comes to unsprung weight and vehicle dynamics. Trending Topics
06-25-2008, 07:46 AM
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I'd also mention bigger than necessary brake discs as well. While bigger discs can assist with better heat absorption, bigger is only better until brake disc temperatures are under control.
06-25-2008, 07:58 AM
#9
Wasn't the general rule of thumb, 10 lbs of rotating mass accounts for a .10 of a second in the 1/4?
An object in motion tends to stay in motion unless acted upon by another force. Your wheels when rotating and in a forward motion want to stay that way, then you turn your steering wheel, causing a list of forces to act upon the wheel/tire combo causing your car to make a turn.
Heavy wheels will react more sluggishly than that of lighter wheels (think gyroscope). It's like trying to push a cloth curtain aside compared to one made of chain mail.
An object in motion tends to stay in motion unless acted upon by another force. Your wheels when rotating and in a forward motion want to stay that way, then you turn your steering wheel, causing a list of forces to act upon the wheel/tire combo causing your car to make a turn.
Heavy wheels will react more sluggishly than that of lighter wheels (think gyroscope). It's like trying to push a cloth curtain aside compared to one made of chain mail.