Lightest weight track wheels

[Tracked Emira]

Is there a consensus on the best tire size for an 18/19 inch wheel setup for the track?

Depends on if you are running slicks or regular tires. If you call Greg from Greg’s race parts he can tell you because he knows both answers.
I will be using slicks so I have to find out myself. Did you pick what wheels you are tracking with yet?

 

[Speedy Emira]

One thing to consider is most manufacturers when stated from a weight that is for the smallest width on that size. When I was looking for wheels one stated from 18 pounds for the 19s but in our width it was 21.3. I would get them to show the wheel on a scale and commit to a weight in writing. For that kind of money they wanna be super light and strong.

 

[Tracked Emira]

Never thought to ask that question since the wheels will be a custom size. It will be interesting to see what the weight difference will be compared to other wheels in the same size and width.

 

[virtualmacho]

Is there a consensus on the best tire size for an 18/19 inch wheel setup for the track?

To retain as much of the OEM geometry, I was thinking along the lines of 245/40R19 and 285/35R19 on custom ordered wheels with the same width and offsets as OEM wheels. For the 3.5 liter Emira V6, that would be 8.5x19 ET57 5x114.3 and 10.5x19 ET54 5x114.3 (the rears will be different for the 2 liter i4 Emira).
These tire sizes are available for the Yokohama AD09 and Bridgestone RE-71RS where I live, in addition to some local options like SHIBATIRE R23. Not as many options as the 18 inch, but doable...

 

[Chriscpm]

To retain as much of the OEM geometry, I was thinking along the lines of 245/40R19 and 285/35R19 on custom ordered wheels with the same width and offsets as OEM wheels. For the 3.5 liter Emira V6, that would be 8.5x19 ET57 5x114.3 and 10.5x19 ET54 5x114.3 (the rears will be different for the 2 liter i4 Emira).
These tire sizes are available for the Yokohama AD09 and Bridgestone RE-71RS where I live, in addition to some local options like SHIBATIRE R23. Not as many options as the 18 inch, but doable...

I just replace my tires after 3 days at the track. I'm trying the Continental ExtremeContact Force. They seem decent. I did a track-ish alignment with -1.5 camber. I think the fronts are only -1.3. I'll see if that helps my sidewall wear.

I had a bear getting them installed. The tirerack installer didn't honor the price. He wanted $600 instead.

Do you have a wheel source? What is a good target price? If I brought the tires and wheels in, I'm sure I'd get a better price.

 

[virtualmacho]

Do you have a wheel source?

I was thinking about asking one of the Hong Kong based forum vendors about the wheels. As for tires, I would recommend sourcing them domestically. I don't think Shibatire ships internationally.

 

[Tracked Emira]

 

[Eagle7]

Interesting video. What he's not taking into account, or at least he didn't say it, is your ability to accelerate (i.e. 0-60) is a function of weight to power ratio, and tire traction. Assuming tire traction is whatever your tires can handle, your weight to power ratio can be improved by reducing weight. This makes it easier for your car to get moving. The extra benefit of unsprung rotating weight allows you to make approximately similar improvements, without having to remove as much static weight. This is where the benefit ratio came from.

It takes power to turn the driving wheels, and get the weight moving. If you make it easier to turn the driving wheels, you can get moving quicker even if the car body weighs the same. You make it easier to turn the driving wheels (unsprung rotating weight) by reducing that weight, which is typically smaller amounts than removing body mass weight. This is the ratio effect. Both will improve your acceleration, but it's typically easier to remove unsprung rotating weight, which also has additional benefits that just removing body weight alone doesn't provide.

In addition to acceleration and braking, there's also the need to control the vertical movement of weight. If you have a 50 lb wheel that suddenly deflects upward, the spring and shock has to manage that, which takes time. If you reduce that weight to 35 lbs for example, the same spring and shock has less mass in motion to control, so it can control it quicker. It's like in baseball where a batter is standing in the on deck circle, swinging 3 bats. He's tuning his muscles to manage that weight, but when he gets up to bat, he only uses one bat, but since his muscles were just tuned to manage 3 times that weight, they can now swing one bat quicker. That same reflex speed works on car suspensions, which is why it's beneficial to reduce wheel and brake rotor weight. There are more benefits than just acceleration and braking.

 

[Tracked Emira]

Interesting video. What he's not taking into account, or at least he didn't say it, is your ability to accelerate (i.e. 0-60) is a function of weight to power ratio, and tire traction. Assuming tire traction is whatever your tires can handle, your weight to power ratio can be improved by reducing weight. This makes it easier for your car to get moving. The extra benefit of unsprung rotating weight allows you to make approximately similar improvements, without having to remove as much static weight. This is where the benefit ratio came from.

It takes power to turn the driving wheels, and get the weight moving. If you make it easier to turn the driving wheels, you can get moving quicker even if the car body weighs the same. You make it easier to turn the driving wheels (unsprung rotating weight) by reducing that weight, which is typically smaller amounts than removing body mass weight. This is the ratio effect. Both will improve your acceleration, but it's typically easier to remove unsprung rotating weight, which also has additional benefits that just removing body weight alone doesn't provide.

In addition to acceleration and braking, there's also the need to control the vertical movement of weight. If you have a 50 lb wheel that suddenly deflects upward, the spring and shock has to manage that, which takes time. If you reduce that weight to 35 lbs for example, the same spring and shock has less mass in motion to control, so it can control it quicker. It's like in baseball where a batter is standing in the on deck circle, swinging 3 bats. He's tuning his muscles to manage that weight, but when he gets up to bat, he only uses one bat, but since his muscles were just tuned to manage 3 times that weight, they can now swing one bat quicker. That same reflex speed works on car suspensions, which is why it's beneficial to reduce wheel and brake rotor weight. There are more benefits than just acceleration and braking.

 

[Eagle7]

Yeah those wheels are incredibly light for that size. The Lotus factory 20x10.5 is 29.54 lbs. Removing 11.5 lbs from just one wheel like that is something else. That's 23 lbs for both driving wheels. You sure pay for it though, they aren't cheap, but if you have the budget.... yeah. Combine that with CCB rotors which for the rear wheels are another 10.6 lbs lighter for the pair, which combined with those lighter wheels means you've removed 33.6 lbs of URW just from the rear wheels. You would most certainly feel that compared to a fully stock car.

 

[Tracked Emira]

These magnesium wheels are less expensive

 

[Beachbum]

$8K !!! Sod that. I'd spend it on driver training and get a lot quicker that way

 

[Tomwa]

This seems very silly marketing. Cars that are dyno'd on by a direct hub bolt on don't make more power because they aren't spinning a wheel and tire.

These dynos work by applying specific brake force to the rollers. Which isn't the same as the traction with the road.

Lightening wheels literally cannot result in more torque. Let's pretend for a moment that the wheels are perfectly connected to the motor. That means the wheels and tires are effectively continuations of the flywheel. A flywheel will never change a dyno reading because it is not adding power, nor is it creating some kind of 'loss'.

 

[Eagle7]

This seems very silly marketing. Cars that are dyno'd on by a direct hub bolt on don't make more power because they aren't spinning a wheel and tire.

These dynos work by applying specific brake force to the rollers. Which isn't the same as the traction with the road.

Lightening wheels literally cannot result in more torque. Let's pretend for a moment that the wheels are perfectly connected to the motor. That means the wheels and tires are effectively continuations of the flywheel. A flywheel will never change a dyno reading because it is not adding power, nor is it creating some kind of 'loss'.

Except they're marketing wheels, so the only way to measure any difference on a dyno, is to use this type of dyno instead of a hub connect. Lighter wheels take less torque to get them turning, so they're just freeing up some of the torque that was being absorbed by the heavier wheels. It's the same thing with more power to the rear wheels. The engine isn't producing more power, there's just less drivetrain loss so more power is making to the wheels.

For a useful test to see the difference in the weight of a set of wheels, they should really do something like a Dragy run, which shows the actual on-the-road performance from 0-60 and takes into account the benefit of all 4 wheels instead of just the two driven wheels. That would at least show the difference in acceleration and braking.