PCA SDR

by **Bill Behun** on Thu Sep 15, 2005 10:07 pm

Say your car weighs 3,000 pounds and it takes you 90 seconds to do the AX course. If you take off 100 pounds (from the car!) and it now weighs 2,900 pounds, how much time would you expect to save?

Since Targas weigh about 100 pounds more than the Coupes, and yet the BRI multiplier is the same (I think) - us Targa drivers are driving with a handicap!

Some of us are wondering how much more awesomely are we really driving!

I expect to take 'heat' for this, but it can't be from Gary Burch - he drives a Targa!

by **Curt** on Thu Sep 15, 2005 10:12 pm

I have heard that 10 lbs is equal to roughly 1 hp.

Website · by **ttweed** on Fri Sep 16, 2005 7:45 am

I am going to take a WASG and say you're going to see approx. a .5-sec. per lap improvement in your hypothetical situation, Bill.

A 3000 lb. car with 200 HP would gain about 3% on its power/weight ratio by losing 100 lbs. That would be about equivalent to adding 6 HP. I don't think you would see that huge a gain in lap time, there is probably more difference created by the extra flex in the Targa chassis than the extra weight--but you are still driving awesomely in that Targa, dude!

TT

by **Don Middleton** on Fri Sep 16, 2005 9:25 am

Bill, we are going to find out...

According to Gary, that 50kg./110lbs. penalty that we Targa folks carry is free to drop without penalty of points. Since we are "classed" with the Coupes, we use their base "book" weight.

So, I'm pulling off the rear bumper assembly and replacing with a fiberglass unit from Mirage. I'll let you know what the weight savings amounts to...

by **Jad** on Fri Sep 16, 2005 9:30 am

.5 seconds or a touch more is probably about right, but the car will excellerate slightly better, corner better, brake better and flex less. For me at least, it really improved the feel of the car from the clutch pedal to the brakes, but I took out several hundred pounds. To test your 100 pounds, just take a cute girl as a passenger and compare times with and without. This may be a bad example, as you will probably be happier with the cute passenger despite being slower :lol:

by **Steve Grosekemper** on Fri Sep 16, 2005 10:38 am

Jad wrote:.5 seconds or a touch more is probably about right, but the car will excellerate slightly better, corner better, brake better and flex less. For me at least, it really improved the feel of the car from the clutch pedal to the brakes, but I took out several hundred pounds. To test your 100 pounds, just take a cute girl as a passenger and compare times with and without. This may be a bad example, as you will probably be happier with the cute passenger despite being slower

Jad,
I think your theory is interesting, however flawed. While this is the easiest way to add/subtract 100-ish pounds there are other factors at work here. If the "ballast" is extremely visually pleasing the driver may be distracted and deliver a lap far below what would be expected for the weight penalty. If the "ballast" is all that plus a good competitive driver, you may pull out the best lap of your life. (Think of a peacock, some men tend to show off in front of a pretty girl-so I hear)

So I suggest using, lead weight... It won't laugh at you when you miss a shift!

by **Jad** on Fri Sep 16, 2005 10:59 am

You have your fun with a lead weight, I will have mine with cute girls (Amy to be specific

)

Maybe if the Charger girls are around, I may even consider further research of having 5-10 of them squeeze in the car for a few laps all in the interest of research of course :mrgreen:

by **Steve Grosekemper** on Fri Sep 16, 2005 11:01 am

Ya, All in the name of research Jad.
Ya, Amy will buy that! :roll:

by **Bob McLaughlin** on Fri Sep 16, 2005 5:26 pm

"...just take a cute girl as a passenger and compare times with and without..."

Just exactly what are you suggesting here, Jad?

by **Don Middleton** on Fri Sep 16, 2005 5:35 pm

"...just take a cute girl as a passenger and compare times with and without..."

Jad, I think you are confusing "autocross" with "autoMATE"... :wink:

by **Bill Behun** on Fri Sep 16, 2005 7:22 pm

Thanks for the info so far guys....and the weight testing concept.

Say, I could try the weight testing concept with my wife, Gail, in
the car but since she weighs ...... oops, I better NOT GO THERE!!!

by **rss996** on Sat Sep 17, 2005 5:51 am

Jad, you could always throw Tami in your car at the next autocross...

You might have to bring your boxing gloves to fight off Bill though..... :roflmao:

The way Dynes has been driving his new 911, he could also be a good candidate! :shock:

by **bibbetson** on Sat Sep 17, 2005 10:37 pm

Having driven with and without Tami in my car all season, I agree with the .5 second per 100 lbs guess. Actually, I would say that it is a little bit more, but that probably has to do with corner weighting more than total weight. I consistently drop .5 to 1 second in timed runs. David thinks I'm sand bagging, but I think it's more like carrying sand bags. :oops:

Oops, I better not have just associated my wife to a sand bag. :shock:

by **Bob Gagnon** on Sun Sep 18, 2005 10:27 am

I think if I had Tami in my car I would be 0.5 seconds faster!!!

Seriously though, the times when I have been consistently riding with friends back and forth and turning credible repeatable times, I would guess 150 pounds is worth around 0.5 to 1.0 seconds or approximately what Bill has noted.

by **JamesWilson** on Sun Sep 18, 2005 5:58 pm

Cool, I just dropped 112lbs in battery, A/C, spare stereo cables, and rear seat headrest....oops, 50lb+ roll bar going in this week...d'oh!

Now if I can get it to rev above 4K rpm, that would be fantastic....I bet THATS worth more than a second!!

-JW

PCA SDR

Lose car weight, go how much faster?

Lose car weight, go how much faster?

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