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light weight wheels, does it matter ????

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#65 ·
It would have to be a massive difference in weight between the wheel sets to be any kind of an issue. Thank about it, if a 300 pound guy loses 50-75 pounds, is it gonna make his car faster when he is driving it? Not enough to be noticeable in any way.
 
#66 ·
silvic15 said:
It would have to be a massive difference in weight between the wheel sets to be any kind of an issue. Thank about it, if a 300 pound guy loses 50-75 pounds, is it gonna make his car faster when he is driving it? Not enough to be noticeable in any way.
Click to expand...
There is a difference. A reduction in unsprung weight will improve braking, handling, and acceleration. Read the link in the first post.
 
#67 · (Edited)
Testing before and after wheel weight on my 2010 Toyota RAV4, I saw no difference in horsepower and torque numbers.
Stock Wheel vs Lighter Wheel - Dyno Results

However, when I looked at acceleration vs time, the speed at which the lightweight wheels got to any specific mph was much faster than the heavy, stock wheel/tire combo.
My stock aluminum wheel/Runflat tire was 63lbs. My after market wheel/tire combo is 33lbs a piece. Total of 30lbs per wheel/tire shaved off, 120lbs of wheel weight total. Acceleration and stopping improved tremendously. 1/4 mile times from this change went from 14.5-14.6 average to 14.1's. I also purchased a tire that had a reduced diameter than stock. I don't recommend it but it had the same affect of using an underdrive pulley (X4 ....4 wheels). It's an awesome feeling to say the least but I don't autocross or road race the RAV4. Just basic driving and 1/4 mile bracket racing on weekends.
Thread ---> Lightweight Wheel Tire Question

Just saying.......lighter wheels/tires work big time. But most already know this.
Did the same thing on my slow CVT Fit. It's not running low 15's with an intake, exhaust and lightweight wheels by mistake. My Rav4 runs average of 13.7-13.8's with same combination (Best of 13.6). The lightweight wheels/tires play a significant role in this.
 
#68 ·
Myx said:
Testing before and after wheel weight on my 2010 Toyota RAV4, I saw no difference in horsepower and torque numbers.
Stock Wheel vs Lighter Wheel - Dyno Results

However, when I looked at acceleration vs time, the speed at which the lightweight wheels got to any specific mph was much faster than the heavy, stock wheel/tire combo.
My stock aluminum wheel/Runflat tire was 63lbs. My after market wheel/tire combo is 33lbs a piece. Total of 30lbs per wheel/tire shaved off, 120lbs of wheel weight total. Acceleration and stopping improved tremendously. 1/4 mile times from this change went from 14.5-14.6 average to 14.1's. I also purchased a tire that had a reduced diameter than stock. I don't recommend it but it had the same affect of using an underdrive pulley (X4 ....4 wheels). It's an awesome feeling to say the least but I don't autocross or road race the RAV4. Just basic driving and 1/4 mile bracket racing on weekends.
Thread ---> Lightweight Wheel Tire Question

Just saying.......lighter wheels/tires work big time. But most already know this.
Did the same thing on my slow CVT Fit. It's not running low 15's with an intake, exhaust and lightweight wheels by mistake. My Rav4 runs average of 13.7-13.8's with same combination (Best of 13.6). The lightweight wheels/tires play a significant role in this.
Click to expand...
Lightweight wheels won't change the way your car dyno's because your not adding horsepower but as you mentioned it will be quicker.
With that said in the summer I changed out to lighterweight Enkei PF01 wheels and Falken summer tires and the stickier tires made more of a noticeable difference than the lightweight wheels.
 
Discussion starter · #70 · (Edited)
silvic15 said:
It would have to be a massive difference in weight between the wheel sets to be any kind of an issue. Thank about it, if a 300 pound guy loses 50-75 pounds, is it gonna make his car faster when he is driving it? Not enough to be noticeable in any way.
Click to expand...


Dyno Runs - The effects of wheel/tire weights on wheel horsepower
[HR][/HR]Test:
Davenport Motorsports (www.davenportmotorsports.com) of Canada, wanted to see the dyno effects of running different wheels on cars. They took a factory 2012 Camaro SS and ran 3 dyno runs. They ran the first run with a set of aftermarket wheels, the 2nd run with a set of stock factory wheels and the 3rd run with a set of HRE P45S wheels, all in 20” sizes.

These results highlight the effects of rotational inertia on drive-train losses (the hp lost between the engine crank and the ground). Wheels and tires contribute to drive-train losses as energy is used to spin up the wheels (and decelerate the wheels under braking). From the dyno chart you can see the effect of replacing factory wheels with lighter HRE wheels and see the negative effects of installing heavier aftermarket wheels.

Results:
1. (Blue curve) Factory wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 68 lbs combined per rear wheel. – Max hp: 371 hp, Max Torque: 375 ftlbs - (Baseline)
2. (Red curve) Aftermarket wheels: 20”x9.0” with Pirelli 275/40-20 tires weighing 72 lbs combined per rear wheel – Max hp: 369 hp, Max Torque: 373 ftlbs - (A [-] loss of 2 hp and 2 ftlbs)
3. (Green curve) HRE wheels: 20”x11.0” with Nitto 315/35-20 tires weighing 60 lbs combined per rear wheel – Max hp: 380hp, Max Torque: 384 ftlbs - (A [+] gain of 8 hp and 9 ftlbs and that is running a 2” wider wheel/tire combo)

Conclusion:
The engine obviously still cranks out the same amount of hp and torque, the lighter HREs simply waste less of it before it gets to the ground. Also interesting to note is that the gains are not just peak gains, but gains across the entire rev range. If they had done a braking test, we would have seen similar results as the rotational inertia effects also have a significant effect on how much energy is used to stop the wheel/tire combo vs. stopping the car. We talk about these effects all the time and focus on designing lightweight wheels with low rotational inertia, but it isn’t every day that you get to see real hard data showing the true effects.

 
Discussion starter · #71 ·
silvic15 said:
It would have to be a massive difference in weight between the wheel sets to be any kind of an issue. Thank about it, if a 300 pound guy loses 50-75 pounds, is it gonna make his car faster when he is driving it? Not enough to be noticeable in any way.
Click to expand...
there is no secret to weight reduction, it's all physics...

DBA brake of Australia link: Brake Discs- is lighter better - Disc Brakes Australia



All performance fanatics talk about reducing unsprung weight. Yes, a rotating disc does have a certain amount of rotating inertia or a flywheel effect which requires power to accelerate and to decelerate. It takes approximately 24 Nm (18 lbf-ft) of torque to get those 9.5kg disc spinning up to 134km/h (80 mph) and back down to zero when braking. The lighter 8.5kg disc requires approximately 20.5 Nm (15.1 lbf-ft) which is a little better than 10% saving in energy required to accelerate and decelerate the same vehicle. On a 6 liter Pontiac GTO with 542 Nm (400 lbf ft) of torque you probably won’t notice a 3.5Nm improvement in torque whereas on an ultra light small performance or race car you may.
 
#74 ·
1/4 mile times would not be as good an indicator as dyno runs due to driver error, even with the same driver.
 
#75 ·
kev604 said:
Lightweight wheels won't change the way your car dyno's because your not adding horsepower but as you mentioned it will be quicker.
With that said in the summer I changed out to lighterweight Enkei PF01 wheels and Falken summer tires and the stickier tires made more of a noticeable difference than the lightweight wheels.
Click to expand...

I stopped short of saying that it won't show any horsepower and/or torque gains. That's why I tested it. I still don't want to conclude that it will not show horsepower/torque gains/losses because you see dyno graphs of lightweight/underdrive pulleys showing a horsepower gain and the same concept applies. No extra horsepower/torque is being generated by the engine, only freed up to move the car vs turning the pulley. However, THIS shows up on the dyno as making (or horsepower freed) more horsepower. Do you mind explaining that for the masses? Because I can not! Hehehe!

As I say on the other boards, I'm not one for explaining why something worked the way it did anymore. I used to do that years ago. I just do, show the results and let the smart people have at it. It's a lot more fun that way. :eusa_dance:
 
#76 ·
Myx said:
I stopped short of saying that it showed any horsepower and/or torque gains. That's why I tested it. I still don't want to conclude that it will not show horsepower/torque gains/losses because you see dyno graphs of lightweight/underdrive pulleys showing a horsepower gain and the same concept applies. No extra horsepower/torque is being generated by the engine, only freed up to move the car vs turning the pulley. However, THIS shows up on the dyno as making (or horsepower freed) more horsepower. Do you mind explaining that for the masses? Because I can not! Hehehe!

As I say on the other boards, I'm not one for explaining why something worked the way it did anymore. I used to do that years ago. I just do, show the results and let the smart people have at it. It's a lot more fun that way. :eusa_dance:
Click to expand...
Less horsepower needed to move the wheels means more horsepower to move the car.
 
Discussion starter · #77 ·
All performance fanatics talk about reducing unsprung weight. Yes, a rotating disc does have a certain amount of rotating inertia or a flywheel effect which requires power to accelerate and to decelerate. It takes approximately 24 Nm (18 lbf-ft) of torque to get those 9.5kg disc spinning up to 134km/h (80 mph) and back down to zero when braking. The lighter 8.5kg disc requires approximately 20.5 Nm (15.1 lbf-ft) which is a little better than 10% saving in energy required to accelerate and decelerate the same vehicle. On a 6 liter Pontiac GTO with 542 Nm (400 lbf ft) of torque you probably won’t notice a 3.5Nm improvement in torque whereas on an ultra light small performance or race car you may.

Generally a car manufacturer will do all the math explained here and much more to determine the ideal disc mass (weight) for the vehicle and we can assure you it isn’t in their best interests to add weight to their vehicles or give away unnecessary kg’s of metal.

link: Brake Discs- is lighter better - Disc Brakes Australia
 
#78 ·
I replaced my OE 18's, when I got new tires. I didn't originally intend to get wheels, but had hated the saw blades since I got the car. The look and price of the Konig Inceptions sold me on them.

They're not light, but 22.6 is better than 29.0 any day!
 
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#80 ·
Got these comin in for daily driving. Yeah they are crazy small but weigh absolutely nothing. Keeping my 18" TSW's.







I will weigh them when they arrive.
 
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