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Any real proof or data that shows lighter wheels = faster ET/Lap times?

ace72ace

Zaino, I put that $hit on everything
1,242
71
Just as folks like to reduce rotational mass any where possible with an aluminum drive shaft, lighter weight wheels should also lead to a faster car. It seems like a no brainer, that more HP per LB = faster vehicle. But is there any proof, real data, that shows this is true?

New Ford Racing wheels are 31/31.5 lb each, around 200ea, and Forgestar F14's are 400ea at 24/24.5ea.

So the 64$ question is.... are the lighter wheels 'worth' twice as much?
 
18x10 Drifts weigh about 24lbs and cost $150. Price of wheel comes down to the construction of the wheels too. Light weight and strength = more money. Still many have tracked the Drifts successfully without any problems. As far as weight goes I have no data to prove anything. However, I lighter car with the same horse power with the same driver will be faster on the track.
 
The laws of physics pretty much proves it! Do you think F1 would be building cars out of unobtanium if it didn't make a difference? Colin Chapman ring a bell? ;)

Now, the second part of your post is a different question. Certainly, as you get deeper and deeper into development of a racecar, the $/sec increases dramatically. And you have to look at the combined effect of several improvements. So in your example, the wheels or drive shaft or whatever, individually, may only be worth .01 sec per lap, but the combination is worth .1 sec. Right there is the difference between winning and loosing.

Even at the grassroots level, a .3 sec/lap advantage can be insurmountable. Think about that--two Miatas chugging around the track and one finishes .3 secs ahead (that's about nose to tail at their speed) after running the same 2.2 mile course in 14 turns. And that's considered a huge gap. So if one guy can spend cubic dollars to narrow that gap .1sec at a time, he will unless the rules say otherwise.

Weight also plays a big role in heat/durability--brakes, suspension movement, etc.
 

ace72ace

Zaino, I put that $hit on everything
1,242
71
I'm aware of basic physics, a lighter drive shaft and wheels should be faster, but I asked if anyone had proof.

For example "I averaged a 12.4 ET at my local track, and after I installed an aluminum shaft, I ran consistent 12.2-3" or "My lap times went down by .2 after upgrading my wheels"...

I didn't have any baseline runs with my stock drive shaft, but the butt dyno tells me the DSS shaft gets the power to rear wheels faster. And yeah I know most all of the hardcore track guys on this site run 18's, for all the reasons discussed in the racing section. I'm interested in upgrading to 19" staggered for street duty, the 18's can come later on. Now it's a tough call to spend 2x the money for lighter Forgestars or stick with the heavier Laguna Seca style Ford Racing wheels. Can't go wrong either way, but if I can justify the cost, I could go for the higher performance wheels.
 
ace72ace said:
I'm aware of basic physics, a lighter drive shaft and wheels should be faster, but I asked if anyone had proof. /quote]

The physics proves it. You are asking for anectdotal evidence. And it's more complicated than just weight. For example, your driveshaft. It may be faster with the aluminum shaft--but that's probably because it's one piece rather than two pieces with a hunk of rubber between them. With wheels you also have to look at where the weight is on the wheel--close to the hub or out on the edges. Wheel A might be 3 lbs lighter, but if the weight is all out on the outside, the rotational advantage may be lost (although the total weight loss advantage is still there).

You also have to look at how other components of the car affect it. Car can be light as hell (total weight and rotational), but if you don't have your set up right it may not translate to ET.
 

Grant 302

basic and well known psychic
ace72ace said:
I'm aware of basic physics, a lighter drive shaft and wheels should be faster, but I asked if anyone had proof.

For example "I averaged a 12.4 ET at my local track, and after I installed an aluminum shaft, I ran consistent 12.2-3" or "My lap times went down by .2 after upgrading my wheels"...

Maybe not the proof you're looking for, but yes, I had hard 1/4 mile numbers from a while back for my 2000 GT going from 17x8 stock rims to 15x3.5 draglites up front. I can't quote the numbers, which are pretty small, but the gains are real when comparing just the front swap.
 
Since you are interested in street use for now, I think go with the less costly wheels or stick with stock wheels. I did notice a difference when going to 18x9.5" Nurburgrings, though. The steering felt lighter, and I seemed to have less backlash transitioning to engine breaking on the street. Not sure why, but the difference was noticeable.

It seems to me like only you can really answer the question of what mods are worth the cost versus benefit, since that depends on your finances and goals, IMO. But if street use is all you want right now, I would consider looks as well as performance. Unless the Forgestar looks are worth that much more, I would just buy some SVE drifts or save up for braking mods.
 
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1
Sometimes you do an upgrade due to driving feel.
Whether or not a wheel change makes a measurable difference in lap times is irrelevant compared with the difference you get in the feedback of the car.
Less unsprung weight = the car respond better, goes over bumps more effectively, brakes better. Essentially, less input to do something, and less labored feedback from the car in the execution of an action. You will feel a difference--no doubt. Just like how the unsprung weight of the rear axle is easily felt.

I would say putting on lighter wheels is akin to putting on a lighter flywheel, or a short throw shifter. It is difficult to pinpoint a timing improvement. But you will immediately notice the difference regardless....and if that is something which you value, then it is certainly worth while to make the change.

However, I wouldn't purposely change to lighter wheels if I'm chasing after a time reduction. There are other more effective things which could be done to shave time.
 

Domestic Product

Big fat tires and everything !
ace72ace said:
Just as folks like to reduce rotational mass any where possible with an aluminum drive shaft, lighter weight wheels should also lead to a faster car. It seems like a no brainer, that more HP per LB = faster vehicle. But is there any proof, real data, that shows this is true?

New Ford Racing wheels are 31/31.5 lb each, around 200ea, and Forgestar F14's are 400ea at 24/24.5ea.

So the 64$ question is.... are the lighter wheels 'worth' twice as much?

Simple question, no easy answer. For me for street, the answer is no get what you like. For track or drag the answer is yes but to what degree and cost ? based on the budget and over all car set up you have should set this.
I have the LS wheels on my car, love them. I have tracked the car with them and passed some very expensive cars with light wheels I must say. But I do plan on getting some 18s for track use and will be looking at getting into the lowest cost light wheel. Going back and forth with Drifts, Forgestars and a couple others.
Here are some interesting articles on wheel and tire weight,

http://forums.nasioc.com/forums/showthread.php?t=2027575

http://www.tirerack.com/wheels/tech/techpage.jsp?techid=108

http://www.carcraft.com/projectbuild/116_9905_light_vs_heavy_wheels_comparison/
 

TymeSlayer

Tramps like us, Baby we were born to run...
3,720
2,551
Exp. Type
HPDE
Exp. Level
3-5 Years
Brighton, Colorado
2012 OEM Wheels 19X9 are 32.5 lbs each and 19X9.5 are 33.0 lbs each - total of 131 lbs.

Forgestar CF5V 19X9 are 21.7 lbs each - 19X10 are 22.5 lbs each - total of 88.4 lbs.
That's over a 42 lb difference. Over a 1% weight reduction.

Throw in a 3-1/2 Alum DSS DS and Borla ATAK ABs and now we are looking at 78.5 lbs weight loss. That's over 2%.

Not sure how much speed I've gained, if any but you take 2% off my fat ass and I'll feel better and move faster too!
 
I'm from Canada where my wife has to use stamped steel rims and winter tires on her 12 Focus Titanium with the handling package. The difference in her car when I switch back to her summer rims is tremendous. Way faster steering input with less effort required and the car "feels" way lighter. I would imagine that on our BOSS' it would feel the same if we dropped weight from the rims and tires.
 

Senderofan

Having more fun than should be allowed..in my Boss
ace72ace said:
I'm aware of basic physics, a lighter drive shaft and wheels should be faster, but I asked if anyone had proof.

For example "I averaged a 12.4 ET at my local track, and after I installed an aluminum shaft, I ran consistent 12.2-3" or "My lap times went down by .2 after upgrading my wheels"...

I didn't have any baseline runs with my stock drive shaft, but the butt dyno tells me the DSS shaft gets the power to rear wheels faster. And yeah I know most all of the hardcore track guys on this site run 18's, for all the reasons discussed in the racing section. I'm interested in upgrading to 19" staggered for street duty, the 18's can come later on. Now it's a tough call to spend 2x the money for lighter Forgestars or stick with the heavier Laguna Seca style Ford Racing wheels. Can't go wrong either way, but if I can justify the cost, I could go for the higher performance wheels.

I think another consideration when looking at switching to18" rims.....is the tire selection. There are a ton of tire options for the 18" rim...19's...not so much. I very much enjoy my lightweight 18" TD racing wheels....thanks Blowfish Racing :D and my "Mr. Feelgood" Conti slicks. I highly recommend it to those who want to experience the Boss at its finest while driving on a track!

Wayne

P.S.

This is MHO....your experience may vary.
 

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