fuzzysig

has anyone done similar test on a 4 banger?
theres pretty much the only test I can find is this done on a big block chevy drag car. with loads of torque the difference in wheel weight would be really insignificant
it did go faster but difference is very small and everyone uses it to show miniscule difference on the track

but I would assume that a low torque car like a stock b series would benefit more from lighter wheels and the diference in 1/4 mile time would be more significant

I personally feel the difference in acceleration when I go from 19lb wheel to 10.8lb wheel of same size
and few friends I recommended to get a forged or other lightweight wheel also saw very noticeable difference in acceleration even on a superhcharged 4 banger.

if anyone has any info on it please share.
or your personal track results etc.

SPOOLINmatt

A smart man once told me, for every pound you take off of rotating mass (wheels, brakes, axles, anything rotating.) The engine sees it as a 6lbs reduction.

spAdam

iTrader: (1)

That's a rather thumby rule, and I've never seen it backed up by any math. You could feasibly math it out to a reasonable estimation with a little high school level physics. Where that weight is in the wheel is just as important.

Here's one with respect to diameter, the principles are all the same, just that a different variable is changing:

https://www.physicsforums.com/thread...hoices.334984/

SPOOLINmatt

I know. It was an NHRA professional category crew chief and builder. I could be a little off on the savings to gain ratio.

fuzzysig

I mean the chevy shaved almost a second off the 1/4 mile but I'm very curious how the lighter wheel will affect times on a low power motor.
so far I haven't found much besides same old arguments where half the people say butt dyno feels good man. other half says its a placebo effect and thread goes nowhere without any data

I mean you cant argue with physics that different variable will obviously produce different result some people just not very good friends with physics

I am willing to let someone borrow my wheels for the scientific experiment at PAC raceway in kent WA

spAdam

iTrader: (1)

It absolutely will reduce your ET. Engine and drivetrain inertia are part of the equation of motion, and more advanced (think high end motorsport stuff) torque request strategy based engine management systems use that inertia in the calculations.

redboost10

Any weight savings will be of some benefit...with that in mind, weight savings on anything with a rotation (for lack of a better phrase) is just that much more beneficial. It is difficult to put a lbs/e.t decrease on this stuff but rule of thumb, a decrease of 100 lbs of stagnant weight = 0.1 et decrease and as SpoolinMatt said a decrease in rotating weight , the engine looks at it as an x6 decrease in weight which is theoretically an increase in horsepower and should be expressed in the et at a decrease more than stagnant weight if we are talking equivalent lbs to lbs (100 lbs stagnant weight loss = 0.1 et decrease so 100 lbs rotating weight loss SHOULD equal >0.1 et decrease). I also think youll see a better improvement in trap speed than the et from loss of rotation weight

I am sure there are way more little experiments than this one, but this particular one has a lot of consistency in all variables ( and yes I know fwd will be different than rwd, but thought I would post this)
1/4 mile weight tests - CorvetteForum - Chevrolet Corvette Forum Discussion

My personal, I had a 99 Si, simple t3/t4 setup, made 364whp, on 24.5" slick, weighed about 2600ish, ran 11.85-90 all day.
Took the same exact setup (didnt even retune since it wasnt needed), put it in a 98 hatchback, same slick, weighed 2180, ran 11.15-20 all day
so a weight savings of 420 lbs = 0.6et decrease roughly. Obviously most/if not all the weight savings was from stagnant weight.
This does not follow any of the above rule of thumbs so this is where throw my hands up.