Moving to lighter wheels and tires

[Shel_B]

Now that I've got my suspension redone, my next upgrade will be new wheels and tires. The items I'm looking at will save me about 11-lbs per wheel. Just wondering if I might notice any improvement in ride comfort or handling. It's always been my understanding that reducing unsprung weight is a benefit in that regard, but is 11-lbs enough to make a noticeable difference?

 

[krzyss]

Going 100lb to 89lb is one thing.
Going 41 -> 30 is different.

Will you reduce rotational inertia too? Keeping the wheel size the same or smaller?

Krzyś

 

[BLND1]

As mentioned above, Percentage of mass reduced will matter more than the number.

Also, Are you going to a wider or narrower tire? More or less aggressive tread design? Etc…

 

[Shel_B]

I plan to keep the same wheel/tire size, maybe, at most, 1/2-inch wider wheels. The primary tire I'm considering is just a small amount narrower in the tread than what I have now, maybe about 1/4-inch. Tread design would be comparable.

 

[Pew]

11 pounds of rotational mass is a huge amount and you should be able to feel a noticeable improvement in acceleration and braking as well as lighter (nimble) steering and slightly better ride quality. Smaller and lighter cars you'll notice pretty big improvement although I'm not sure just how much you'll notice the difference if it's on the 2011 Camry in your signature but I noticed a difference between 2-7 pounds per wheel on my Evo (3,400 driver-less and 3/4 tank full) when I was changing wheels.

The general rule of thumb is 1 pound of unsprung mass can be equated to 4 pounds of sprung mass so if you really are saving 11 pounds per wheel, 11Lbs x 4 wheels =44 Lbs total loss of unsprung mass. 44x4 =176Lbs of sprung mass loss (so basically like you kicked an average size person out of your car.)

 

[Shel_B]

11 pounds of rotational mass is a huge amount and you should be able to feel a noticeable improvement in acceleration and braking as well as lighter (nimble) steering and slightly better ride quality. Smaller and lighter cars you'll notice pretty big improvement although I'm not sure just how much you'll notice the difference if it's on the 2011 Camry in your signature but I noticed a difference between 2-7 pounds per wheel on my Evo (3,400 driver-less and 3/4 tank full) when I was changing wheels.

The general rule of thumb is 1 pound of unsprung mass can be equated to 4 pounds of sprung mass so if you really are saving 11 pounds per wheel, 11Lbs x 4 wheels =44 Lbs total loss of unsprung mass. 44x4 =176Lbs of sprung mass loss (so basically like you kicked an average size person out of your car.)

Well, my Camry specs out at about 3,263 lbs. I have steel wheels on the car now, and they weigh about 25-lbs each, my current tires are 24-lbs each, and then there are the plastic wheel covers (1-lb each?). The wheels I'm looking at are 17-lbs, the tires are 21-lbs. I'm sure there are some rounding errors, but still, it's a pretty good weight saving per axle.

Where'd you find the rule of thumb that 1 pound of unsprung mass can be equated to 4 pounds of sprung mass? Perhaps there's some other good info there about vehicle dynamics.

Thanks!

 

[Pew]

Where'd you find the rule of thumb that 1 pound of unsprung mass can be equated to 4 pounds of sprung mass? Perhaps there's some other good info there about vehicle dynamics.

Brake engineers from PFC, AP Racing, and Brembo use that as a general term since they have to deal with clients that want the least amount of rotational/unsprung mass but have to deal with spec-class cars. I've just heard it numerous times from other track enthusiasts as well but I've never seen an actual formula.

 

[Shel_B]

Brake engineers from PFC, AP Racing, and Brembo use that as a general term since they have to deal with clients that want the least amount of rotational/unsprung mass but have to deal with spec-class cars. I've just heard it numerous times from other track enthusiasts as well but I've never seen an actual formula.

Thanks a lot! I really appreciate your time and effort.

Is that you driving into the weeds in your avatar?

 

[Pew]

Thanks a lot! I really appreciate your time and effort.

Is that you driving into the weeds in your avatar?

LOL yep. On the other side of me is a FRS that I was trying to get away from in a corner. My buddy who was the photographer at the event caught it all. Here's the picture a few frames back of the front lip being destroyed from the rumble strip.

 

[Pew]

*double post*

 

[930.engineering]

11 pounds of rotational mass is a huge amount and you should be able to feel a noticeable improvement in acceleration and braking as well as lighter (nimble) steering and slightly better ride quality. Smaller and lighter cars you'll notice pretty big improvement although I'm not sure just how much you'll notice the difference if it's on the 2011 Camry in your signature but I noticed a difference between 2-7 pounds per wheel on my Evo (3,400 driver-less and 3/4 tank full) when I was changing wheels.

The general rule of thumb is 1 pound of unsprung mass can be equated to 4 pounds of sprung mass so if you really are saving 11 pounds per wheel, 11Lbs x 4 wheels =44 Lbs total loss of unsprung mass. 44x4 =176Lbs of sprung mass loss (so basically like you kicked an average size person out of your car.)

This. Any good driver should notice the difference. Shel, when looking for new wheels keep wheel offset close to stock. Wheel offset affects steering geometry. That being said, I'd also keep wheel diameter and width somewhat close to stock if you don't want to ruin ride. Next point, tires choice (make, type) has huge impact on both ride and handling. Grand touring tire ride nicely, proper ultra high performance (UHP) tires handle great. Not both at the same time, so you probably have to make some kind of compromise here.

 

[Shel_B]

This. Any good driver should notice the difference. Shel, when looking for new wheels keep wheel offset close to stock. Wheel offset affects steering geometry. That being said, I'd also keep wheel diameter and width somewhat close to stock if you don't want to ruin ride. Next point, tires choice (make, type) has huge impact on both ride and handling. Grand touring tire ride nicely, proper ultra high performance (UHP) tires handle great. Not both at the same time, so you probably have to make some kind of compromise here.

Stock offset for the Camry is 45mm, and that's what I'm looking at, stock width as well (although there's one wheel that's 7-in instead of the stock 6.5-

The tires are ones I've used before and liked very much ... standard touring tires.

I'm not looking for performance, just maintaining comfort and some additional "crispness" over what I've got now. Thanks for your input.

 

[930.engineering]

ET45 is popular and should be easy to find. A couple of millimeters shouldn't matter, but 10 mm less would be noticeable on uneven pavement in your steering wheel. Either 6.5" or 7.0" should be fine with a 205 tire. Wider than 7.0" with 205s would result in exposed rims and it would be harder to avoid the wheels getting curbed.

 

[Shel_B]

ET45 is popular and should be easy to find. A couple of millimeters shouldn't matter, but 10 mm less would be noticeable on uneven pavement in your steering wheel. Either 6.5" or 7.0" should be fine with a 205 tire. Wider than 7.0" with 205s would result in exposed rims and it would be harder to avoid the wheels getting curbed.

I appreciate the advice. Standard rubber on the Camry is 215, which should be just fine on 7-inch rims. I really want to stay as close to stock numbers as possible. Fewer issues down the road ...

LOL yep. On the other side of me is a FRS that I was trying to get away from in a corner. My buddy who was the photographer at the event caught it all. Here's the picture a few frames back of the front lip being destroyed from the rumble strip.

In the early 60s, I lived in the St. Louis area, and used to drag race a little in Alton, IL and had the good fortune of running a few laps at St. Charles Speedway as well. Things were pretty rough in those days ... rough cars, rough tracks, and some pretty rough drivers.

Looks like you were having a blast!

 

[meep]

Shel, I have a 14 Lexus GS, about the same size as your Camry. The stock wheels were 29 pounds. I moved to enkei wheels which were 8 pounds lighter and the difference was very noticeable. same size tires, and the wheels were only different by a 5mm offset. Well worth it.

 

[Zaedock]

Jeebus. 29 lb wheels. The wheels and tires on my Jeep weigh 160 lbs each.

 

[Shel_B]

Shel, I have a 14 Lexus GS, about the same size as your Camry. The stock wheels were 29 pounds. I moved to enkei wheels which were 8 pounds lighter and the difference was very noticeable. same size tires, and the wheels were only different by a 5mm offset. Well worth it.

Good to know ... thanks! Which model Enkeis did you get? I saw a beautiful set of white Enkies on a white Camry/Lexus a while back ... man, did I drool ... had never seen white wheels before ... stunning!

 

[Nyati]

Now that I've got my suspension redone, my next upgrade will be new wheels and tires. The items I'm looking at will save me about 11-lbs per wheel. Just wondering if I might notice any improvement in ride comfort or handling. It's always been my understanding that reducing unsprung weight is a benefit in that regard, but is 11-lbs enough to make a noticeable difference?

I went from factory 22.1 lb Civic wheels to 14.2 lb Enkei wheels. Made a huge difference in road feel- shorter braking too. The rotational and unsprung weight savings makes a big difference.

 

[Shel_B]

I went from factory 22.1 lb Civic wheels to 14.2 lb Enkei wheels. Made a huge difference in road feel- shorter braking too. The rotational and unsprung weight savings makes a big difference.

Thanks for jumping in. Were the wheels you replaced steel? What size were they?

Hadn't thought about a shorter braking distance, but it makes sense.

 

[FZ1]

Different strokes. If your steeled wheel Camry tracks straight and the steel wheels balance I would forget reinventing your wheels and tires. I have 2017 Le and prefer the steel wheels. Apply the savings toward a pretty lady or a big block Camaro and go have some fun. Jmo.