Rotating Weight

[TOOSTUBBORN2FAIL]

Anyone have any links to results from changing rotating weight?

I have the chance to lose about 28 pounds of rotating weight with the wheels and tires from what im using now (total for all 4 wheels). Just wondering if id actually notice a FE diff or not.

[SVOboy]

You really don't notice a difference from most things, but that doesn't mean it won't be effective. In this case I would go for it since weight is pretty solidly known to be a bad thing for FE

[orange4boy]

You probably won't notice a difference but it will theoretically make a difference. the factor is greater the further out from the rotational axis you go so 1lb lighter tires would make a bigger difference than 1lb lighter rims. Most of us are making lots of small changes which all add up to big savings.

If you are paying for it, it probably won't pay you back though. Not that that has stopped me.

http://forums.bimmerforums.com/forum...p/t-79243.html

[2000mc]

why kind of driving do you do? might be noticable in town, starting and stoping often, but if you drive mostly highway there would be very little benefit.

aside from mileage, the lower unsprung weight might make your car ride better

if theyre free, try it. extremely cheap, maybe... but returns will diminish quickly as you pay very much at all.


....or DO IT! let us know!

[Christ]

If you planned on getting them anyway, it's worth while, and the MPG is an added benefit.

It's alot harder to change the speed of mass than to maintain speed of mass, which means that lighter rims will, in effect, save your suspension, brakes, and make it so you take less time/fuel to accelerate.

It's not just an MPG thing, it's the cumulative addition that makes things worth while.

[TOOSTUBBORN2FAIL]

i figure i was going to get them anyways for the race car, in 15X10 size for a neon, since that project was scrapped and my daily/race car are now one, 14X6 custom aluminum rims are much cheaper, and will allow me to mount some low RR tires at the same time. Current rims weigh 14.6 pounds a peice, and are shod with 18 pound kuhmo kh16s, in 196/60/14's. New rims should be around 9 pounds, and according to tire rack, bridgestone B381's are 16 pounds a piece in 185/70/14, and should have a much lower RR.

Plus im hoping for a much smoother ride with 7 pounds per wheel knocked off, since the slow lane here isnt paved that great

i think i was mostly curious if anyone had done some back to back testing, however if not i'll do some next summer when i set these up on the car

[tjts1]

I definitely noticed a difference when i replaced my 15" steel wheels with 16" alloys. Turns out the alloys weighted 10lb more per corner. I went back to the steelies.

[busypaws]

My drive is 5.5 miles (one way) and 22 stop lights. Posted speed is never above 35. So I'm concentrating on weight and rotating weight.
I bought some 13inch Honda VX rims (Craiglist) and then put 155/80/13 on them. I lost 6 lbs per corner.
If I commuted on interstate with an average speed at 55 then I would go with Aero mods.

Currently getting 40mpg on my commute in 1.5L 97 Mazda Protoge.

[TOOSTUBBORN2FAIL]

ya, i mostly freeway drive, however im not really worried about making my money back, at this point its more about doings whats right and reducing my pollution as much as possible

especially after my talk with the california air resource board yesturday, with them pretty much saying they dont care at all about global warming

according to the guy i talked to, theres 2 different types of pollution, smog pollution, which consists of carcinagens, and global warming pollution, which is like co2, and such. They said usually global warming pollution usually goes hand in hand with gas mileage, but often smog pollution doesnt, and that there only real concern is reducing "smog" pollution, the co2 and other global warming pollution there not so concerned about. This was told to me by there director of communications. He said there only worried about stuff that cause cancer and puts people in the hospital.

So lets see, if i got this right, california only cares if i increase the chances a tiny tiny bit that 1 more person might die of cancer, but they dont care at all if i increase the chances that everyone dies from the planets destruction?

Of course my dad, who has a doctorate in physics said the guys just talking out of his rear end, so that they can have control over who can and cant do things. With the CARB guy telling me that they give priority to businesses over people who arent going to sell anything, i agree.

This by the way, was in response to my question of whether theres a way my car will pass smog with the alternator removed, since the obd2 will notice that. Of course the answer is no, if the check engine light is on for any reason, you fail, period, even if its unrelated to smog. For instance, if i unplug my battery, like i would if it died and i change it out, my engine like comes on stating that the batteries been unplugged within the last 50 keyons, which would fail me.

rant over

[TOOSTUBBORN2FAIL]

tried to post 2 days ago, but it wouldnt let me, not sure why

anyways, the cars a 98 2.0L dodge neon RT, comes with a close ratio 5 speed (3.94 FD, .81 5TH)

currently has a cold air intake (that will be replaced soon), 4mm larger throttle body (which will be replaced soon), power steering pump impeller removed (so i can use it as an idler pulley for AC), no muffler (picked up and average of 1 mpg), no passenger seat, and an underdrive pulley that saved 5 pounds from stock, plus no wipers or antenna.

Im currently getting 42.18 mpg average, mostly freeway, at 55pmh.

Imediate plans are to put a different tranny in in 2 weeks (3.55 FD, .72 5TH, will drop my 55mph rpm from 2500 to 2000), along with a new clutch/flywheel that saves 6.25 pounds. I plan to delete the alternator this winter for long trips, and build a bracket to adjust belt tension for the AC with the AC compressor. Then with the 28 pounds of rotating weight lost from the wheels/tires, that should be close to 45 pounds rotating weight lost total on the whole car.

Later this year will also begin the aeromods.

Just curious, what section should i start a project log in?