And I think that's the other problem is people not setting up the car properly (i.e. getting larger wheels, lowering the car, never getting it aligned).

The problem Damon is that most people aren't made of money. They will have to pick and choose where they can "splurge" and where they can't. Some picks wheels, others pick large single turbos. If we were all race teams with deep pockets, it would be a different story. Just because someone doesn't have the money to get "the best of the best" doesn't mean they should just get nothing.

If that were true, we wouldn't own FD's as they aren't "the best of the best".

 

Just kidding Damon. Actually I appreciate your comments, and use of discretion.

I think that people are willing to spend more money on looks than performance when it comes to wheels. The stock wheels are very good quality, and very light. However, the wheels are one of the first things that people replace.

 

You know, every time I see an FD with stock rims (even mine), I think they look great. Then a see an FD with aftermarket rims, and all of a sudden the stockers look like crap.

Take a few days and then I like the stock rims again.

 

I hope I am not one who comes off as the type that just writes checks to fix problems because I certainly am not. I'd have been broke a long time ago with this car! If I didn't race my FD so much I could be driving one hell of a nice new car right now and traveling more

Again my point was just that if someone spends $2000 on coilovers, $500 for toe links/trailing arms, $600+ install on jimlab bushings, $1200 for big brakes, $5000+ in single turbo installs etc then they can spare a few hundred extra bucks to get lighter wheels

 

I really like the stock rims. I got very lucky, and fell into a deal to buy a set of chromed stock rims for $200. I feel like I got the best of both worlds. Great quality, light weight and a little bling. If I ever get back into racing, I still have the stockers for a set of race tires.

 

I disagree, but that's the beauty of living in the US and being able to have an opinion.

Like I said, most people are just building their car to "just build it". Dyno queens if you will, so wheel weight means absolutely nothing to them as look is more important. If they could get those big brake kits, single turbo setups and everything else cheaper, you know they would.

Now, there is no "right or wrong" as long as the purchaser understands what he/she is getting and for what purpose. The only wrong way is to buy the wrong wheel for the wrong application. For the street, as asked in this thread, weight really doesn't have that much of a bearing.

 

Exactly .

True, but what about the person who doesn't get all those things and spend THAT much on their car... I could get a great set of used konigs with tires for about a grand that maybe weigh 5 lbs more per wheel than a nice set of nice Volks. Then I would have 1 - 2 grand to spend on other parts of the car. Not to say that I'm doing this, but I think this is the case for many people...

The question evolves to, how would this 5 lbs/wheel really affect the performance of the car? I think it has been answered: that although it may affect it in a track scenario (less acceleration/deceleration), I shouldn't feel it much on the street. Is this a safe assumption?

 

Like I said, I recently went with a 18" setup, fronts weigh 43 lbs, rears weigh 45 lbs. My stockers weighed 38 lbs. There is a noticeable difference in how the car feels, from both a steering and a handling viewpoint. I don't really notice a straightline difference, other than maybe 1st gear's lost a little punch.

 

Quote:

Originally posted by Mahjik
If that were true, we wouldn't own FD's as they aren't "the best of the best".

Sacrilege!

Not to hijack the thread but name something else that for equal $$ you can have:

1. Equal straight line speed
2. Equal track speed

(Optional)

3. Timeless aesthetic looks

 

That's personal preference. However, right now, the Vettes are the best bang for the buck as far as looks and performance.

 

Just for the record my car was not lowered and had an alignment. In fact the rolling diameter was almost identical on the two setups. That being said there was a big difference. Stay light and maintain the correct offset would be my advice.

 

Roll on 20s, and install some hydraulics...yo

 

Yes, the diameter was the same, however your contact patch I'll bet was quite a bit more. If you look at with the FD weighing 2800lbs and half of that on the front spread across two 8" wide rims running on 225's. Now, spread that across wider rims with wider tires. How does that affect your turning with increase friction due to the larger contact patch?

I think people are confusing heavier weight causing their handling differences instead of the size of the wheels.

While the weight does make a difference, it's basically as Jim pointed out that it's treated the same as curb weight.

 

No, the size of the wheels were 8" and the tires were 235/45 ... that is almost identical to stock. I'm sorry but what part don't you get? It is like you are convinced I am making this up.

 

Who said you are making anything up?

However, anyone who has been through a chemistry or physics class will agree that what we have is not an exact "controlled experiment".

There is more to the handling than just weight of the wheels. If you could use the stock wheels and add 5lbs per wheel and test it, that would give you a "controlled experiment". However, just slapping on 18" wheels which have a different tire, different width and different weight provides too many varibles to say which one(s) are causing the difference in the handling. Hell, there is a difference in handling just from using a better tire.

It's kind of like people and the radiator stuff. People are switching from an old radiator that has bent up fins and has been beat on for years to a new aluminum one claiming how great it is. However, how much would the difference be between "2 new radiators"...

Like I said, while I do believe weight is a factor, I don't see a total of an additional 25-30lbs being that noticeable "on it's own". People have lightened their cars up more than that and never notice a difference (as well as adding heavy stereo equipment).

 

Boy I guess my engineering degree doesn't count for science classes.

 

I'm not sure what you are reading into this discussion, but go ahead and make that controlled experiment. I'm sure a lot of people besides myself are curious about the results.

 

Everyone open your physics texts to the chapter on Angular Momentum...

The weight of the wheels don't account for jack as far as the weight on the contact patches. The car weighs nearly 3000 pounds; a few extra pounds more at each corner from a heavier wheel is not going to make the steering noticeably heavier from increased contact patch friction due to heavy wheels. The steering WILL get noticeably heavier at speed when the heavier wheel is asked to change direction, and even more so if the offset of the wheel has increased the scrub radius of the front end (increased scrub radius will also greatly increase kickback at the steering wheel). Ever played with a spinning top when you were little? The gyroscopic forces of the spinning top cause it to resist movement in any direction not pointing along its axis. Spinning wheels on cars experience exactly the same forces. Get a loose bicycle tire and spin it by hand while holding the axle; then try moving it around. It's suprisingly difficult even though that is much lighter than a car wheel and not spinning near as fast.

As I mentioned earlier everyone understands the benefit of a lightweight flywheel on an engine, right? Lightweight wheel/tire combinations have exactly the same effects and they are all good. Lighter wheels are not better because they present less weight for the motor to carry around, they are better because their lighter weight represents a much less amount of energy that must be overcome in order to make them change direction in steering, bump/rebound travel, speed up or slow down. Even if you disregard the kinetic energy advantages the lighter wheel will be easier for the damper to control and will afford better grip all else equal.

The energy within an object that is spinning (wheel, tire, flywheel etc) is tremendously greater than the energy in an equally massive object that merely travels with the load (spare tire, fuel tank, driver, seats, vehicle chassis) etc. This is the reason that any rotating or reciprocating part should be made as light as possible.

 

To me a controlled experiment is one where a minimal set of variables change-hopefully one. Controlled experiments don't just happen in a lab. There are basic elements that make up a controlled experiment; theory, control variables, and repeatability. I had two that changed-weight and offset. I linked the changes in the car to both of these items. I've also had a different set of 17s that were slightly heavier than stock and were 8.5 and 9.5 in width for front and rear. I felt a slight difference, but more things changed, so I left that out of the discussion. There were at least two other people that mentioned that the car will feel different with heavier wheels. These people agreed the car felt more nibble and the steering felt lighter.

How many different sets of wheels have you tried on your car? Can you speak from experience? I can. You just started firing away on what the changs of my car probably were ... lowering and width without even asking if I had changed them. The guy wanted to know if weight mattered and I gave him a perspective from my own personal experience. That information indicated what he could be looking at if he changed. It is more than just handling in what I am saying. The feel of the steering is different. It is lighter and that can be a trait that some people desire and some don't. I have one friend that hates light steering and almost always eliminates the power steering on his cars.

 

On my FD? None. On the many other sports cars I've owned since I've been driving over the last 15 years, MANY!


Actually, if you read my comment, it was not directed "at you":

And I think that's the other problem is people not setting up the car properly (i.e. getting larger wheels, lowering the car, never getting it aligned).

I had no idea what you changed or added and never pretended to...

No problem. I've been there and done that. I didn't change anything drastically over 1" of difference in the new rims over the stock ones, but there was absolutely zero difference in my handling or response of the car driving it on the street (and the weights varied on the cars depending on what I liked since that's all I was into at the times). The cars ranged from FC's, 300zx's, 240sx, etc.. So I'm not talking about putting dubs on a Civic.

Now, if I had been tracking those cars, I'm sure I would have noted a difference. However, I didn't know anything about tracking way back then.

 

This is the only part I don't necessarily agree with. While there is a difference of the flywheel needing the spin with less mass, I don't believe wheel weights hamper this function at all (since the wheel isn't free spinning since it's in contact with the ground surface).

However, things like offsets and width I do believe all play a roll in the "steering feel" which is what I was pointing out that weight is NOT the only factor when it comes to steering feel or handling.

As far as the contact patch, I beg the differ on the amount of difference it makes. If you take a two non-fictionless surfaces, apply a force down from one to the other, and then measure the force needed to spin the top surface. Now, do the same but making the contact surface larger should result in more friction (across more area) thus more force to spin the upper surface. The same should work in reverse as for gaining better traction.

 

Lets say the average price of a good condition stock FD is $16,000. Please find a Vette for the same price that outperforms it.

If you are talking a 2004 Z06 you're looking at around $52,000. That leaves $36,000 to upgrade that stock FD. That should give me enough to have performance upgrades to walk on a Z06 and leave money for hand stitched leather dash and door panels.

If you're looking at buying a used Z06 you can grab one for around $35,000. At that price you can shop around and find yourself one heck of a FD.

I have a friend that had a '02 Z06 until he had the dealer take it back under the CA lemon law after bending the frame while caynon running (from the Gs not from bumps or anything stupid). On another run the FL brake rotor cracked. He also broke the rear end, blew a transmission and many other things on the car in about 8 months.

I'm not saying FDs are the model of relability either but I haven't heard about stupid manufacturing issues (underengineering basic stuff) like I have on Z06s and Vipers (know a guy who had his front window crack at Thunderhill in a Viper).

 

I raced a Viper where he stepped so hard on the gas that it pulled the throttle cable through the firewall. Turns out the retaining piece on the firewall is plastic came out ... he had to call a tow truck.

 

The rotational inertia of the wheels does in fact have the same kind of effect as rotational inertia in the flywheel. The wheels start at one RPM and end up at another RPM when you accelerate the car, so they damp acceleration in the same manner as a flywheel. Obviously, there are some differences in where they are connected to the driveline (after the tranny), but they are still accelerated rotationally when you accelerate the car.

-Max

 

The thing is, the wheels which have power, have to move the entire car, not just the wheel itself. So for acceleration and power, just as Jimlab pointed out, it should be treated as curb weight. In that sense, adding 20-30lbs total weight to the car will require more power to move it the same speed it was going than without the extra weight. It takes XXX amount of power to move a 3000lbs object XXX as fast. Now if you increase the 3000lbs to 3050lbs but XXX power stays the same, then yes the acceleration is not the same. However, thats not due to the rotational weight of the rims, but the total weight. The real question is how much difference is that 20-30 extra pounds overall going to make? IMO and experience with using "heavy rims" on other cars for "street driving" as asked in this thread, very little to no difference when weight is the only thing modified (yes, I used the same tires and rim sizes on the other cars because I was cheap and just looking for new rims).

Now, the scenario that Damon pointed out for manuvering the front wheels with rotational forces happening should be interesting to map out in a physics sense. The only thing I didn't like about the analogy is that holding a bicycle wheel and moving it is a little different than the steering mechanism on the as those components do not support the entire weight of the wheel (as you would be doing holding the bicycle wheel). However, weight is still a factor as that is the downforce onto ground in which you are still going against, just not directly.