NewFoundPower

I was talking to Tim (not sure of his user name) at the MSR-Houston NASA event last weekend and he mentioned that he'd removed all of the carpeting/padding/etc from his car (C5 Z06). He said that all together it weighed about 40 lbs, so I was thinking of doing the same myself, as well as removing the passenger seat for Time Trial events. That should save at least 50 lbs, but I was wondering if it would make enough of a difference in lap times to be worth it.

I run NASA TTA, and drive the car on the street every once in a while, but just for fun so I don't care about extra noise. I just wouldn't want to tear up the floor pan getting in and out and putting stuff in the trunk when I drive to the track. Anyway, just wondering if it's something that would benefit my times enough to consider. Thanks for any opinions!

davidfarmer

well, power-to-weight is around 10:1, so 10lbs=1hp. In your case, that's around 4 hp. However, since since removing the passenger seat actually hurts your bias some, I would disregard that last 10lbs.

4 hp isn't much, so 40lbs really isn't much.

doing a quick spreadsheet from zero for 1000feet, you'd arrive approx 0.06sec quicker, and traveling about 0.8mph faster. If you have 2 long straights, that would give you just over 0.1sec from acceleration. Cornering speed would go up around the square root of the decrease in weight, or about .006%. So all in all, in best case, you'd see around 0.8sec.

Maybe worth it to you, but I'd not sacrifice any comfort unless I could save at least 100lbs

0Louis @ LG Motorsports

3.5-6 tenths. A good rule of thumb is 100#s= .8 secs. Remember, you have to accelerate it, stop it, and corner it.

HP is not the same, as it only aids in acceleration, not decel and cornering.

wtknght1

Depending on the car, driver, setup, track layout, etc, a good rule of thumb is 50lbs is worth .5 seconds per lap on a 2 mile course. .5 per lap after a 20 lap race is worth 10 seconds. How competitive do you want to be?

And BTW, if you remove the carpeting, padding, etc AND remove the seat, you'll save a lot more than 40-50 lbs. Depending on your rules and what you can and can't remove, the seat weighs between 30-35 all by itself. Take out another 30-40 for carpeting, padding, etc. That's some good, cheap, easy speed!

drivinhard

TTA in the southeast is pretty tight, C5Z's only tenths apart. every lb.

our car's interiors are as bare as our bank accounts

AU N EGL

So how is that diet going ?

RAFTRACER

I'll find out , NASA just wrote 50 lbs off of my car

Seriously every little bit matters.....I would listen to Louis and Chris they probably know more about the effects of different weights than anyone on here.....

drivinhard

mine or the car's?

the car's is costing a lot more

John Shiels

yank it it is not hard to put back in 1-2 hr. seat rugs are near 100 lb if I remember correctly.

wtknght1

Well, another thing I've found over the past 2+ years is that weight is a lot like tire pressure - there's a sweet spot… and a point that's exponentially bad.

Again, depending on your car and all the other factors, 50 lbs might only be .25 or .3 or .5, or whatever. But if you add 50 lbs to a car that’s at the limit of its capabilities, now those lap time go to hell in a hand basket. I’ve been trying to get the CRB to understand this…without much luck. The T1 kit was designed for a car that weighs 3280 with the driver. Add race fuel to that and you come up with about 3350lbs. Anything more than that and you exceed what the springs, brakes, etc were designed to handle. So if you add 50 lbs to a 3280 car, it’ll probably be .5 per lap. But if the car is already at 3350, another 50 on top of that might be .7 or .8 per lap. And to make matters worse, that .7 per lap at first might end up being 1 full second or more per lap after six or seven laps because of the cumulative effects on the brakes, tires, etc. You won’t know until you test.

The bottom line: If you’re carrying more than the minimum weight, you’re just throwing your lap times away when you don’t need to.

GAS

David....I think I hurt myself trying to keep up with your math!!! But then I am just a cheesehead. Danny can drive (no pun intended) home the point that the 100th's do add up. I think he may have won NASA Nationals by something like 1/100th in 2009. So the moral of the story.....every ounce can count depending on how competitive ya want to be!!

RAFTRACER

I am absolutely certain had the car @ Nationals in 2009 been 50 lbs heavier that we would have lost, instead of won by .01 sec.....although if I could have run either the Friday or Saturday early AM TT session that .01 wouldn't have mattered....

At anyrate every pound makes a difference , especially 50 or more of them.....

NewFoundPower

Well I definitely want to be as competitive as I can, and the results from last weekend were pretty close in TTA. Saturday and Sunday had 4 and 3 cars finish within about .75 sec, so it looks like it will be advantageous for me to try to shed some pounds where I can. The car weighed in at 3276 with me (about 190) and about 1/4 tank of fuel.

I couldn't find anything in the rules stating that removing carpet and a passenger seat adds points, so I just have to stay above my minimum competition weight and weight/power ratio. If I take out the passenger seat and carpet it sounds like I could get down close to 3200, where I'll still be within the rules.

Thanks for the input!

sperkins

I should have weighed everything as drivinhard and I gutted the whole interior over the last several weekends. I'm guessing we probably removed close to 300lbs if not more. I'll have to add balast to meet the rules and I can't wait to see the difference since my car is not even remotely sorted out. It'll be a pure weight difference only.

0Randy@DRM

I spent two hours taking out a pound on Sunday. Yes it matters.

Randy

Jason

You run TTA? Going to Nats? If so I wouldn't worry about it. I'd even add weight. It'll make the suspension ride smoother. Smooth is fast.

96CollectorSport

What did you eat???
Too much cheese in your diet?

TTA is a very competetive class, you will need every little advantage that you can come up with.

BTW there's more than 50lbs to loose in the interior, and minimum weight (Car with driver and fuel) for a C5 (Z06 included) in TTA is 3173 so you have a lot of weight you can loose.

kwhiteside

Pure? Are you forgetting the new Spec3+ clutch.

sperkins

Oh yeah.:o

But.... Mark found my cheater turbo hidden in the rear brake duct so now it's a wash.

0Randy@DRM

I have the stomach flu, so my weight has been dropping 10-13 times a day They say it only last a week or two. That means, I will be down to 100 pounds in two weeks. Easier to scale the car right?

Just trying to beat you guys without spending any money.

Randy