Importance of weight loss?
 

Nub here~ Was just wondering what you guys thought about getting lighter parts (e.g. carbon fiber stuff, lighter exhaust components, etc) opposed to mild bolt ons like an exhaust or CAI.

How much weight would one need to lose to really feel it? I mean when I go from an empty tank to a full tank, thats about 13 gallons~79-80 pounds and you can really feel the weight + the movement of the liquid.

:iono: any thoughts or comments? =D

Depends if it's sprung or unsprung weight..

um taking weight away from a car gives all the benefits from other parts all in 1. MPG, acceleration, and handling all improve with weight loss. That's why the most expensive performance cars are almost completely made of carbon fiber. A 500hp vehicle can make the same 0-60 times as a 1000hp vehicle all because of weight. That's where this car shines. It starts at around 2750lbs. Many cars cant dream of that weight these days. Wheels, exhaust, spare tire + tools and (heavy) battery delete can get you down another 100 easily. I cant think of a downside of losing too much weight in a car

Just an FYI: mild boltons like an exhaust or CAI usually replace stock parts that are heavier. So besides adding a few horsepower, these parts make your car lighter as well.

win win

Except for my Invidia Q300, which was +2.5lbs or something over stock. But still true in 90% of cases like you said.

Ultimately dropping weight is fun and a very worthwhile endeavor, but you won't see a per-item improvement very often. It takes the cumulative effect of a lot of weight drop in order to see significant improvement.

Whats sprung or unsprung? lol sorry.

Sprung weight are those things supported by the suspension.

Unsprung weight are those things not supported by the suspension such as wheels, brakes, tires and suspension components.

Pound for pound, lightening the unsprung weight has a much greater (positive) impact on performance.

^This.

Lowering unsprung weight will make a noticeable different. If you have a wheel/tire setup that is 5lbs less at each corner, then that's 20lbs less rotational mass to spin. There's almost no point in carbon parts for weight reduction on this car. The stock body parts are pretty light and I doubt that the cf replacements would make that much of a difference. Maybe the trunk and doors but that's about it.

As stated above, aftermarket bolt on parts are lighter than some of the stock parts. Battery, headers, and exhaust could easily drop the weight a good chunk. Plus all of the bs in the trunk.

I stripped out the trunk and replaced the exhaust with a single exit muffler delete track pipe. The exhaust alone saved about 23lbs and losing everything in the trunk saved close to another 80. So my car weighs nearly 100lbs less than stock. But in all honesty, I didn't really notice any difference in the car. Maybe if I add a lighter battery, lightweight crank pulley and up the power with some bolt ons, I'll notice something a change

I believe I calculated that 200 pounds lost on our car is 15-20 hp at the wheels.

Like Colin Chapman said, "Adding power makes you faster on the straights. Subtracting weight makes you faster everywhere".

Wrong ... Blanket statements are never good.

From a purely physics perspective, weight loss on a car is good.

From a practical standpoint, weight loss is not as important as weight distribution, especially with modified suspension. If you go with a fuel cell and lighten the car by ~60lbs or more in the back of the car, ideally you'd want your suspension spring rate and dampening to match the changed weight distribution.

Your suspension should also provide a degree of squat/antisquat based on the weight... and this is all towards your ultimate goal.

So, to answer the original question:
Yes, lighter items are great for going faster, but there's a hidden drawback. In general, losing weight on unsprung parts yields benefits.

-alex

I've driven several EG/EK Civics (I know, not a good comparison) both before and after cost effective weight dumping procedures like lighter wheels, lighter exhaust, super-lightweight batteries, and ditching the spare tire and tools...

the results were always the same...the car felt faster everywhere (high, mid, low rpm) , even if on paper, the acceleration improvements were only a tenth or two...

I think that the twins are perfect as is.

In the past I have gone overboard tuning cars only to be disappointed with the final outcome. My best advice from many years of lessons learned concerning this very topic is for you to invest your time and money into driving lessons.

The driver mod is the single best improvement that you can make.

Cheers,

-Nate

My car...right now. is 2580 .. some sprung weight loss. some Unsprung.. I have replaced the battery with a 3.2 lb lithium model. Lighter/more efficient brakes, Lighter wheels. Lighter exhaust components...Header/Overpipe-catpipe, muffler. Suspension is lighter than stock components. and lighter seats..Corbeau FX1 Fixed back..

With all that done. I definitely FEEL the difference. well that and the tune..
I compete nationally in Autocross so Power to weight is pretty important. with my rule set ...not sure what else I can do to reduce more weight. if Bigtime weightloss is the goal and optimize stuff......then you could look at Carbon Fenders, hood. trunk and Driveshaft.. Get rid of all excess stuff and strip the car out. I know that some of the race vehicles are down intoe the 2200/2300 range..Hope that helps.

Bill