Sorry about the long subject, but I wanted to be specific. I realize that by reducing unsprung weight, the suspension has less weight to deal with when driving (not the weight that the suspension has to support, but the weight the suspension has to deal with when keeping the tire in contact with the road).

Can anyone give me real world driving impressions of what reducing unsprung weight feels like? I was thinking of getting some 16" Volk TE-37, or some other uber-expensive Japanese forged wheel. Maybe the MF-10 (good Lord those wheels are nice...).

How does the reduction in weight affect braking, turning, and acceleration? I'm looking to make more than a cosmetic change (although of course aesthetics are a big part of the decision); I want the wheels to add some functionality. I'm keeping with 16" because I want to continue to run S-02. These are some of the best tires I've ever used (on the street). This upgrade is just so costly, I want to know if I get any real benefits from it other than just looks. Thanks for reading.

 

Although the S-02 is a wonderful tire...it is a very heavy tire. This is one thing many folks don't think of when trying to reduce u.s. weight. The right combo of a low wieght wheel and tire will give you better acceleration and less wear and tear on suspension components.

 

I went from a lightweight, forged 17" wheel to a heavier and wider 18" wheel that's probably a good 3-5lbs. heavier per corner before the unsprung weight conversion.

And to tell u the truth, I've come to realize that a lot of people including myself split hairs about performance and it's understandable given that we're pretty damn in love with cars.

Like this Dave Dunbar character talking about how the S-02s are awesome but they're heavy ass tires... well are u saying that you go with say a lighter tire like a kumho ecsta 712 because it weights a pound or two less than the Potenzas? Pls. unless you measure your car by tenths of a second at a time, where is this $$ that's supposedly elevating your accel/handling/braking game really going towards?

keep it simple, define the scope of your car (track, street, mix), get what you freakin' love, and the rest will fall into place.

 

I have done some pretty extensive research, testing, etc. on three aspects of S2000 ownership. Intakes, exhaust and tire/wheels. I began my interest in the latter when owning a 2000 MR-S. It became obvious that in sportscars, unsprung weight has a major impact on how the car performs every function asked of it, be it handling, straight line acceleration, grip, braking, etc. Everything.
If you do a google search about the topic, you're likely to find wild claims that for each pound of unsprung weight either gained or lost, expect 5-6x difference as opposed to a static lb. Nonsense.
I've pointed out before but will once again state that several owners of the Spyder (at that time) and I spent weeks on this very subject and with the help of individuals with more degrees than they care to remember, the factor was closer to 2.25 to 2.5
I've been using accelerometers since 1998 and now use the Tazzo exclusively. My testing of the past five cars I've owned have all supported the factor of 2.5 as a way to accurately predict the "performance" difference from a timed perspective when manipulating unsprung weight.
I also have another formula that I've devised which applies to the S2000.
It simply is the following: Each lb saved/gained = .0021 seconds in the 1/4 mile. After MANY Tazzo runs, this formula is literally a given for me.
The variances in runs following modifications lead me to average out all of my times and .0021 was the number I came up with.
So, let me give you my own example to help break this down for you.
The stock rear S0-2 tire I believe weighs 25-lbs. The front tire weighs 23. I could be slightly off but if memory serves me, those are the #'s. The front wheels weigh 17.8-lbs and the rears 18.6. Again, this is memory at play here. In other words, combined weight of tires/wheels on an OEM S2000 is 169-lbs.
After ordering my tire/wheel combo (Rota Slipstream racing black 13.5-lbs with Toyo Proxes T1-S tires which weigh 19.4-lbs front, 19.6-lbs rear), the difference between what I was using at the time (18-inch wheels in the rear, 17-inch in front for a total weight of 188-lbs) was 188-132= 56-lbs multiplied by 2.5 (factor discussed earlier) for an unsprung weight loss equivilent to 140-lbs static weight.
Using the formula above, mind you this is BEFORE the wheels/tires arrived, I determined all other factors being equal, the drop from bling bling 18-inch wheels down to lightweight 16-inch racing wheels should result in my S2000 being .3 seconds quicker in the 1/4 mile.
140 x .0021 = .294
If you want a HP equivilent to the mix, take the # and divide that by .022
.294 / .022 = 13.4 hp
To cut this short, after install I returned to my test "track" and performed a series of runs (after a few days, I probably logged 20 or so...not all 1/4-milers, the Tazzo tests acceleration between RPM points in a specific gear...much more accurate). The result? The car was .292 quicker in the 1320, just as I had predicted, which supports my theory that for every 1-lb of unsprung weight gained or lost, expect a 2.5-lb difference.
Going with those Rotas and Toyos for me was akin to gaining nearly 14hp worth of performance. One can argue, "you don't actually GAIN horsepower" but common sense tells you, a lighter wagon will make the horse pulling it much happier.
As for braking, a DEFINITE improvement as well. The handling of my car is significantly better as well. In the future, when I get tired of cleaning these black wheels, I may go to a 17-inch tire but you can bet your ass it will be as light as possible. I would never go back to any wheel which weighs 17-lbs or more. Why install a CAI or exhaust system for 7-8hp and offset that by adding heavy wheels? That's just my take on it. Everyone dances to their own drum beat. There are some incredibly beautiful S2000's out there with gorgeous wheels but I've still got that "gotta reduce some weight" mentality which carried over from the Spyder. I had that car down to 2030-lbs and for all intense purposes, created a $20,000 Lotus Elise. The horsepower had been upped to 150 (stock 138) and my 0-60 sprints could be nose to nose with most S2000's. That was a QUICK little beast and handled like rolling Krazy glue.
Weight is our enemy.

 

so what does all this really get u russ? money? fame? fortune?

or pretty much satisfaction that you've spent a lot of picking out catch up mods for your s2000 to make up for your massive 6'4" frame v. most of these punk ass asian kids weighing 120 pounds wet and wearing boots?

 

Nice write up Russ

 

[QUOTE]Originally posted by WRS2K

 

i definitely see your points and you're obviously doing what u love and that's why i respect you.

but really, the WRS2K in me is just saying that you have one really ugly car even if it is so much lighter than mine. it's a trade off u know? and another guy who's really into weight reduction is the krazik guy. IS a fast driver and makes sense given the amount of time and effort he puts into tracking the car... he really really cares about saving a pound or two here and there.... but from some pics of him that i've seen, he's a fat dude straight and simple. he could save so much weight and be healtheir if he shaved off another 60 pounds F1 driver style. but then here he is posting how to get rid of windows, get rid of that black goop thing that covers the underside of the car... wtf?

my point is...i really don't know.

all in good fun my friends

btw, happy b-day.

 

[QUOTE]Originally posted by WRS2K
so what does all this really get u russ?

 

Russ, 1/4 mile times are 90% BS when not doing it on the same day in the same conditions etc. u know this.

and with the s2000 let's up that BS meter to 98% just for kicks. and why we're even talking about 1/4 mile times when it's but just one dimension of weight savings benefits makes me realize the bigger BS that it really is when defined by s2000 owners.

you may launch better cuz your narrow ass rims and ghetto tire combo allows u to spin the rears much better than teh stock setup.