Lighter wheels = any E.T reduction?
 

Anyone have real world honest results in E.T. reduction when replacing standard type centerline wheels with really light wheels?

Re: Lighter wheels = any E.T reduction?
 

I have done extensive back to back testing with lighter wheels, lighter drive shafts, gun drilled axles, alum spools and any other low weight rotating part that I can find and have had zero improvement. As my car is very low HP, I would think that if any car would improve it would be mine. If I was starting over with a new car, I would still buy all of these lightweight parts but if you are on a budget, don't waste your money.

Jim Caughlin
SS/FS 6019

Re: Lighter wheels = any E.T reduction?
 

I tend to agree with Jim. Remember that most of the super-trick, gun-drilled, unobtanium stuff was designed for Pro Stock (and maybe Comp), where getting the entire car to a crazy light weight was the challenge. I honestly think that today, it's mostly for the coolness factor.

Re: Lighter wheels = any E.T reduction?
 

Back in the stone age (Mid 1970's)Jim Morgan changed from a wide "Cook" steel wheel on his SS/GA 428 Mustang to a light weight wheel (don't remember the brand) of the same size and he was consistently about .09 quicker in the 1/4 mile. The Cook wheels were quite heavy if anyone remembers them. Both were 14 inches wide. I went with him quite a lot back in the day and was doing his heads back then for him and Dickie Estivez who ran the Al Joniac 1968 light wt. that has been restored to original condition and his brother in law ran a 1969 Convertible. They all 3 picked up after changing from the heavy Cook brand wheels to the lighter wheels.

Re: Lighter wheels = any E.T reduction?
 

Bruce, how much actual difference in weight are you talking? Those Centerline wheels are already a lot lighter than a 15 X 7 Magnum 500. I'd think a slower car wouldn't see anymore advantage because you are accelerating the mass at a slower rotational speed than say an A/S or A/SA car. I agree with Jim.

Re: Lighter wheels = any E.T reduction?
 

Interesting idea , but I don't agree with Jim . I believe the lightweight stuff does work for all weights of cars , but the faster the acceleration rate, the more important lower inertia parts are . Higher horsepower cars accelerate quicker , so for them its more important . Also the farther that lightweight part is from the engine the less effect it has on hp it takes to spin it up . Another point is a tire is only spun up from zero to maybe 1600 rpm in say 9 secs , a driveshaft from zero to 8000 rpm , and an engine spins up several times , depending on how many gears you have in the trans . So if I were to prioritize what things to concentrate on reducing mass just for pure acceleration it would be the engine , then the tires , followed by the wheels , and finally the driveshaft . There are other reasons for lightening up stuff like overall weight , ease of doing , or expense . If we all had unlimited funds , we would do all the above .

Re: Lighter wheels = any E.T reduction?
 

Spending money to reduce total empty weight AND unsprung weight is usually a good investment. depending on the combination and how fast the car is.

Re: Lighter wheels = any E.T reduction?
 

Yep, lighter, stronger always better! Return on investment in this case? Like you I'm spending that $600 or more on engine/trans.
I wouldn't spend it on slightly lighter than light wheels. I still agree with Jim, for the results save the money if you are on a budget.

Re: Lighter wheels = any E.T reduction?
 

You would be surprised at how many revs a tire actually turns from the time it leaves the starting line until it goes a 1/4 mile. Actually About 150 to maybe 175 times depending on if you have smaller or larger diameter tires. The same with engine maybe 1200 actual revolutions on an engine turning 7200 rpm in a 10.5 second run

Re: Lighter wheels = any E.T reduction?
 

I think we're saying the same thing, just differently. As another poster suggested, if I'm choosing between gun-drilled, 40-spline axles, an aluminum spool and a lightened ring and pinion, I would probably save the money and put it in the engine. Reducing unsprung mass does allow quicker acceleration of the component in question, but the question becomes "At what price for what gain?"

Re: Lighter wheels = any E.T reduction?
 

I`d have to agree with Jim on this as well. I`ve done back to back runs with steel wheels and Centerlines with the same size tire and saw no noticeable improvement on a V/SA Buick Skyhawk or Skylark.

Re: Lighter wheels = any E.T reduction?
 

I went from four Stock steel wheels to four light aluminum wheels on my '56 Chevy Jr Stocker, and was disappointed to find zero change in ET or MPH.

Same results from going to an aluminum spool, lightened ring gear & drilled axles on my C/MP '69 Camaro a few years later. I have wasted a lot (to me) of money testing "trick" parts over the years.

Re: Lighter wheels = any E.T reduction?
 

The further away from the centerline of rotation the greater benefit of rotating weight reduction..

Remove 1 pound of rotating weight from the OD of the flywheel vs. a 1 pound reduction from gun drilled axles.....

It's called moment of inertia.

Just sayin'

Your Results May Vary...L-O-L
 

I maybe shouldn't wade in here because I really don't have a dog in the fight, but on the other hand, perhaps this info can help someone:

Decades ago, when I worked for the late great Super Stock & Drag Illustrated, I penned a tech article on the effects of reducing wheel weight. Sheldon Gecker (most here know of Sheldon) had run some well documented A-B-A tests of wheel weight on his Super Gas car. He went as far as having some heavy wheels made (same configuration as his light wheels), ran them and then switched to lighter wheels and then back to heavy wheels. The car definitely picked up with the light wheels. Keep in mind this was a relatively light, relatively high horsepower car. If I recall correctly, the goal was to improve the vehicle reaction and short times. Obviously for Sheldon, it worked.

On a similar note, shortly after that I was personally involved in another magazine driveshaft test on a very well sorted, consistent mid to high class NHRA Stock Eliminator car. I won't mention the racer's name, but he is smart, seasoned and meticulous. A stock DOM shaft was swapped for a lightweight (illegal of course...L-O-L) aluminum shaft and then back to the DOM shaft (typical A-B-A test). Conditions were monitored closely and it was all accomplished in a short period of time. The car definitely picked up with the light shaft.

My take by looking at the comments here is that the power and weight of the car can make a considerable difference. As a result, your results may vary...L-O-L

Re: Your Results May Vary...L-O-L
 

I remember reading a similar article on driveshafts,was the test done on a Buick?.I recall there being no measurable gain between the Alum.and DOM.There was a fair gain using a metal matrix $haft. gsa612

Re: Lighter wheels = any E.T reduction?
 

My old friend Charlie Ford told me over 30 years ago that "If everything I bought that was suppose to pick me up a Tenth or so was true.....I'd be going zero right now!"

Ain't it the truth......lol

RJ

Re: Your Results May Vary...L-O-L
 

Yes....L-O-L...but we never used an aluminum shaft. The test was steel versus metal matrix aluminum back to steel. :)

Re: Lighter wheels = any E.T reduction?
 

[QUOTE=RJ Sledge;569877]My old friend Charlie Ford told me over 30 years ago that "If everything I bought that was suppose to pick me up a Tenth or so was true.....I'd be going zero right now!"









Awesome quote...

Re: Your Results May Vary...L-O-L
 

I tested DOM vs alum driveshafts, both were 3" dia with the same size ujoints and yoke, DOM was 13#, alum was 10#. Tested them back to back and zip difference. I didn't even add the 3# back into the car. I cross the finishline at 9400 so I figured this would for sure help, no such luck.

I would suggest that some of the tests discussed above were in cars that were overweight. If that's the case, go for it but if you are having to add lead back in to compensate, not so much to be gained. As I said previously, I would still buy these parts if I was building a new car, just that I realize that there is very minimal value in them.

I'll be at Seattle this weekend, we can continue the debate there.

Jim Caughlin
SS 6029

Re: Lighter wheels = any E.T reduction?
 

I guess we have all bought a lot of stuff that was supposed to be good for a tenth and were disappointed.

However a long time ago Paul Forte told us one of his 904 transmissions would be a tenth quicker than the 727 we were running and he was right.

I am guessing about half of that was less static weight and the other half was reduced rotating weight.

Re: Lighter wheels = any E.T reduction?
 

Gentlemen--- Car Craft Magazine had an article a while back whereby they tested different transmissions and the Horsepower required to turn a transmission. I do not know if these are totally stock trans or were modified in any way, I also do not know if theTorque Convertor was used in these tests. These are THEIR results:

Powerglide---18 HP
Turbo 350-----36 HP
Turbo 400-----44 HP
C-6--------------55-60 HP
C-4--------------28 HP
A904------------25 HP
727--------------45 HP

Re: Lighter wheels = any E.T reduction?
 

I read about the 727/904 difference decades ago. There was an article (maybe in the Direct Connection manuals) where Paul was testing with a few Stock and/or SS cars around the mid-'70s. I remember the difference being stated as .15, with everything else being made as equal as possible. (converter, weight, etc.)

Physics says that any weight reduction will help a race car accelerate faster, even if it's rotating and the same reduced amount replaced with static weight. But any of the small gains can often be masked by some of the many other variables that can't be consistently and minutely controlled.

My theory has always been to try things that "might" help.....as long as there was a certainty that it couldn't hurt.....and you could afford it. Unfortunately, the "afford it" part usually restricts me.

Re: Lighter wheels = any E.T reduction?
 

Somebody also had an interesting comparison of differential efficiency. I don't recall who, but do remember that a Dana 60 and GM 12 bolt were at the top while the Ford 9" was at the bottom. Mopar 8 3/4 was in between, but I don't remember what else was included.

Re: Lighter wheels = any E.T reduction?
 

The Rotational benefit from lighter wheels is minimal.

Losing weight going to a aluminum vs steel wheel is a benefit.

Less Friction from meshing or rolling parts would offer bigger gains.
Or going to a Radial Tire vs Bias.

Re: Lighter wheels = any E.T reduction?
 

Many years ago one of the popular magazines did a drag test using a stock vehicle and comparing the difference in et between stock steel wheels and aluminum racing wheels..weight difference approx. 60lbs and approx. .010 difference in et. More recently on the Hot Rod Network there was a redo of that test but there findings were 80lbs difference which meant .011 and 1mph gain. The whole scenario is if you keep taking rotational weight off here and there it all adds up..the more the better. Again not for someone on a budget. Just my opinion

Re: Lighter wheels = any E.T reduction?
 

If the magazine tested wheels on a stock vehicle, they would see more benefit than a race car, due to HP difference.

As for transmissions, my T350 Pro Trans with lower dia & lighter internals (and other things I likely don't know about) is a solid min 5 hun quicker than another well known/professionally built T350 I had.

Re: Lighter wheels = any E.T reduction?
 

Flywheel weight vs wheel weight is a totally different situation. When I reduced the flywheel/clutch weight and dia, I got HUGE results.

Jim

Re: Lighter wheels = any E.T reduction?
 

Car probably slows down - on the low HP stuff there isn't enough power to get the car moving if the flywheel/clutch is too light, need that inertia to not bog it down....

I'd say my low HP car doesn't repeat well enough to measure gains of a few hundredths, weather and wind move it more than that run to run.

Re: Lighter wheels = any E.T reduction?
 

Because we can't test in a "vacuum", our test results are subject to interpretation based on any differences in track surface, track temps, wind direction changes, and any other number of variables. I do believe that if you apply all of the things that are supposed to be better, then it will be better. You just may or may not see the results immediately.
It's the same in my electrical business, I can guarantee that you will use less electricity by switching to a more efficient electric motor or LED lights, but you might not see a difference in your electric bill due to differences in running time of all of the components are different each month.
Dan

Re: Lighter wheels = any E.T reduction?
 

Ha! That is a "Classic" #loveit

Re: Lighter wheels = any E.T reduction?
 

I was just about to say exactly that. The further away from the center of rotation the greater the benefit. Easy way of testing this is to hold a ten pound weight in your hand , and then put that same weight at the end of a 1 foot rod, grab the opposite end of the rod and try to hold it up.

Re: Lighter wheels = any E.T reduction?
 

But, it HAS to be worth something, right?

Not the very first place I would spend money.

But, we all have light wheels.

Re: Lighter wheels = any E.T reduction?
 

Think of it another way, which car will accerate faster, one with a 12/32/15 tire or a 16/32/15 tire? It takes more HP to turn that big tire (heavier) the same speed as the little one, or how long does it take you to carry 10 lbs 100 feet? Then 100lbs 100 feet.

Re: Lighter wheels = any E.T reduction?
 

Think about A-B-A testing it during a track rental. I did with a 13 second Jr Stocker. Wished I had spent that money someplace else. Who would buy heavy wheels today?
I doubt anybody. Lots of light wheels available now. Higher hp cars will see less than my old 13 second 265" '56 Chevy.

One of those things that just HAS to help, right?
I would not BS myself into thinking it's a big deal.