Chrysler 300C & SRT8 Forums banner

1 - 10 of 10 Posts

·
Banned
Joined
·
1,625 Posts
Discussion Starter #1
The SRT8 300c has some really nice stock wheels.
After adding 22's to my own car, I'm wondering just how much the SRT-8's wheels weigh?

Its 0 -60 is 4.8. How much more speed could be gained if you switched its wheels to carbon fiber ?
 

·
Registered
Joined
·
376 Posts
Every hundred pounds off weight usually gets you a tenth in the quarter, give or take, of course. Carbon fiber wheels? Big bucks!! Hell, do they even make such an animal? Where you will pick up time is cutting diameter without messing with gear ratios and such. A 20" wheel is not good for 1) cutting a good 60' time and 2) will almost always be slower than a smaller diameter wheel.
 

·
Registered
Joined
·
8 Posts
I always say the max size you should be if your looking at acceleration is 18". They offer the best compromise IMO between handling and weight.
 

·
Registered
Joined
·
626 Posts
Every hundred pounds off weight usually gets you a tenth in the quarter, give or take, of course. Carbon fiber wheels? Big bucks!! Hell, do they even make such an animal? Where you will pick up time is cutting diameter without messing with gear ratios and such. A 20" wheel is not good for 1) cutting a good 60' time and 2) will almost always be slower than a smaller diameter wheel.
Also a lighter wheel has even more potential to lower times than removing pounds from elsewhere on the car. Rotating mass not only has to be accelerated forward but you also are rotating it around an axis.

It is also "unsprung" weight so a lighter wheel will allow the suspension to work better, improving handling. One of my projects when I get my shop done will be to see if the forged aluminum control arms from the last generation E55 AMG will swap out with our cast iron ones.
 

·
Registered
Joined
·
113 Posts
I have Tezzen 22' wheels with dunlop tires . Before I install them I was curious on how much they weight . They are 75 pound each wheel. Now that is gone slow me a bit I think :) . I keep my old 18' wheels for drag racing. They are much ligther
 

·
Registered
Joined
·
377 Posts
I'm still not getting this 17" is faster than a 20" and a 20" is faster than a 24".
If the diameter is the same then there is NO gear change or leverage difference. It doesn't matter if the wheel is 17" and the tire makes up the rest or the wheel is 24" and theres barely any rubber left. If the dimensions are the same (and other parameters such as traction)can someone please explain how one is slower or faster than the other. I understand the unsprung weight theory but I'm having a hard time swallowing that 5-10 lbs on less than a race ready vehicle is going to make the difference in a win at the track. I'm not saying it isn't true, it's just that I don't understand it and think there are so many othere areas that are more important.
 

·
Premium Member
Joined
·
7,787 Posts
diameter

Maistro is right on, it's the overall diameter of the tire and wheel combo, not just the wheel.

A 22 with a really low profile tire can have exactly the same diameter as a 20 with a larger profile, thus yielding the exact same effort to turn it.

A few pounds at the wheel is generally undetectable, but huge heavy ones are going to take their toll.
 

·
Banned
Joined
·
1,625 Posts
Discussion Starter #10
I'm still not getting this 17" is faster than a 20" and a 20" is faster than a 24".
If the diameter is the same then there is NO gear change or leverage difference. It doesn't matter if the wheel is 17" and the tire makes up the rest or the wheel is 24" and theres barely any rubber left. If the dimensions are the same (and other parameters such as traction)can someone please explain how one is slower or faster than the other. I understand the unsprung weight theory but I'm having a hard time swallowing that 5-10 lbs on less than a race ready vehicle is going to make the difference in a win at the track. I'm not saying it isn't true, it's just that I don't understand it and think there are so many othere areas that are more important.


YES there is a difference.

The difference is the mass of the 17" metal rim over the 20" metal rim (or larger). Metal carries more mass than the rubber. Therefore, it should take a car a greater amount of force to accelerate when it has 22" rims with 2" tires - instead of 17" wheels with 7 inch tires.
 
1 - 10 of 10 Posts
Top