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NickD
08-22-2018, 12:50 PM
I have read of the benefits of reducing rotating mass, the data I've seen doesn't seem to make it that important.
Im looking to change wheels.
The first set Im in love with I found out weigh 36 and 38lbs I believe. (20x9 and 20x11 Shelby wheels)
Ive debated some of the new flow formed wheels that weigh 25lbs.

Convince me to get the light ones vs the pretty ones lol

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hammerhead
08-22-2018, 01:08 PM
Lighter wheels help quicker acceleration as do lighter fly wheels and suspension parts maybe not be much difference unless your looking for tenths...

Stephen06GT
08-22-2018, 01:09 PM
Unless you are racing the car on a regular basis, the a few extra pounds won’t mean much when on the street. If you are racing, get a dedicated set of track wheels and forget about the 20s.

Old Fart
08-22-2018, 01:19 PM
Get the ones you like best!

newbiestangowner
08-22-2018, 01:21 PM
Just get the wheels u really Like!
Real happy with my Forgestars though, somewhat lighter than others and didn’t break the bank.
- “ butt dyno “ felt it more responsive (turns/ accel. Etc)
Only after initial change, after you get used to it and becomes the same feel
- gas mileage?? Minimal


X2 if you looking for tenths have your dedicated track set ready
Even in your stock set - up (Honda) you’d spank my coyote all over the place


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RedSN
08-22-2018, 02:34 PM
If the data you have seen states that it's unimportant, then get the pretty wheels.

But don't try and justify it by denouncing physics.

G-ForceJunkie
08-22-2018, 04:01 PM
I used to think (10+ years ago) that each pound of wheel weight was worth roughly 7 pounds of static weight, but I'm not sure on what basis I had that impression. Around 5 years ago, I read a comparison someone did that found 1lb wheel weight differences were worth more like 3 lbs static weight each, which makes more sense. I don't have any of those sources handy though, and the wheel diameter is a consideration of how much the effect is as well. So if you're dropping 10lbs per wheel, it's like 120lbs of static weight - using the 3:1 rule.

RedSN
08-22-2018, 09:04 PM
I’ve heard a similar ratio Andy. Could probably do the math, but it’s already after beer-o-clock.

Rotational components like wheels, rotors, flywheels, driveshafts, etc. Have both a static physical weight that needs to be moved along with the car, but also a rotational mass or momentum that needs to get spun up to speed. Both tasks require torque and horsepower. So saving weight on something like a wheel has a greater effect on overall performance than say lighter heads.

stangstevers
08-23-2018, 08:01 AM
Don's about to go full on Aristotle on this thread :D

NickD
08-23-2018, 08:57 AM
The unsprung weight was one thing I was hoping someone would comment on
The articles I read were using 1/4 times as a comparison and it was such a slight difference but the idea of 13lbs less per corner sounds like it would have to change the feel of the suspension and have some sort of butt Dyno increase?
I have a alloy drive shaft but haven't put it in that I think would be the same idea slight measurable increases but should change the feel?

As others said forget about racing if I was to or took it seriously I'd have a dedicated setup this is strictly for a the street

Heavy wheels are Shelby CS2's
Lighter option are something like LMR GT7

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hammerhead
08-23-2018, 09:04 AM
weight savings with unsprung weight - drive shafts - light flywheels - windage trays - and anything that creates drag - is marginal, maybe 5-10 hp but do enough of them and you can easily make 50+hp

stangstevers
08-23-2018, 09:47 AM
I think you guys are talking about mass moment of inertia...

So a 30" wheel that weighs around 30 pounds is about: 147 lb-ft

And one that weighs 20 pounds is: 98 lb-ft

So like around 200 lb-ft total savings I guess. I'm not sure how to translate MMI to HP though... I think this is like saying saving 40 pounds total on your wheels is like saving 200 pounds on the body for acceleration?

RAT ATK
08-23-2018, 12:43 PM
Can’t comment on the street feel, but knocking off 10lbs per corner on my track setup transformed the feel of my car. Car feels more responsive, more willing to go where I want it to.

Mrods
08-25-2018, 04:11 PM
This was an interesting and objective test by Brenspeed. Shows a 5% gain with lighter wheels.

https://youtu.be/5MUnG5hrEEI