Weight Reduction
#16
01-23-2010, 03:17 PM
Join Date: Dec 2009
Location: St. Petersburg, Florida
Posts: 803
Rep Power: 59 
http://www.porsche.com/usa/models/91...s/?gtabindex=5
it's 88 lbs. 3,406 lbs vs 3,318 is 88 lbs. I guess it's possible that the PDK version vs. manual was not as heavy on my 997.1. Regarding PDK, I just couldn't see myself buying an automatic Porsche regardless of how much quicker the computer can shift.
Last edited by michaeldantep; 01-23-2010 at 04:46 PM.
#17
01-23-2010, 03:19 PM
Join Date: Dec 2009
Location: St. Petersburg, Florida
Posts: 803
Rep Power: 59 Unless you are tracking the car and looking to win club races, shaving a hundred or two lbs off the car is not going to change the performance in any way you would notice. Just to give you a sense of how much you'd have to do to a car to really improve the performance, look at the Ring times for the GT3 and C2S. It's only something like 8 seconds on a 13 mile long track. Just over 1/2 second per mile average.
But, things like lightweight forged wheels and light tires (Some tires are 22 lbs and others 26 - 4 lbs adds up) can turn into something you will feel if you are really sensitive to it (quicker pick-up). Then there are 2-piece floating rotors where you can save a few more lbs at the wheel (unsprung / rotational mass).
But ripping stuff out of a car and thinking that saving 20 lbs here and there is going to make the car faster just isn't realistic in any way you can sense.
I remember taking my 07 C2S from bone stock to moderately modified and through the process probably lost 100 lbs. It took GPS based TraqMate telemetry to see the differences. Yes, my butt dyno suggested the car was quicker and Traqmate confirmed my feeling. But we're talking 10ths of a second here and there, not something that means much on the street.
That all being said, the "feel good" mods that make some amount of sense to me are headers, cats, mufflers, wheels, tires, and rotors. I'll add software (I have Softronic and there is an improvement). But that's where I'd stop. The car will feel quicker, sound great, and look fresher with some aftermarket wheels.
But, things like lightweight forged wheels and light tires (Some tires are 22 lbs and others 26 - 4 lbs adds up) can turn into something you will feel if you are really sensitive to it (quicker pick-up). Then there are 2-piece floating rotors where you can save a few more lbs at the wheel (unsprung / rotational mass).
But ripping stuff out of a car and thinking that saving 20 lbs here and there is going to make the car faster just isn't realistic in any way you can sense.
I remember taking my 07 C2S from bone stock to moderately modified and through the process probably lost 100 lbs. It took GPS based TraqMate telemetry to see the differences. Yes, my butt dyno suggested the car was quicker and Traqmate confirmed my feeling. But we're talking 10ths of a second here and there, not something that means much on the street.
That all being said, the "feel good" mods that make some amount of sense to me are headers, cats, mufflers, wheels, tires, and rotors. I'll add software (I have Softronic and there is an improvement). But that's where I'd stop. The car will feel quicker, sound great, and look fresher with some aftermarket wheels.
Last edited by michaeldantep; 01-23-2010 at 03:25 PM.
#18
01-23-2010, 08:35 PM
From the Porsche site, on a manual trans the convertible is 3,318 lbs. or just 187 lbs. heavier than the coupe on the C2S and if you have the PDK option, it weighs 88 lbs. more than a manual. Comparing this to the new E90 BMW M3, the coupe weighs 3,704 lbs. and the convertible is 441 lbs. heavier at 4,145 lbs.
You shaving like 25 lbs. off the rear seats or the exhaust is not going to make up for the extra 180 lbs. disadvantage you have from owning a cab.
The fact is it will not make a huge difference. So why bother? Just enjoy it as it is
#19
01-23-2010, 08:42 PM
I agree with you, but I sometimes just do research to see the "what if's?". The unsprung weight reduction is the important thing from what you wrote and a few others. What are the light tire brands/models? I have Bridgestone and how much are those rotors just for kicks?
Front: Factory 19.85 lbs./GiroDisc 17.05 lbs.
Rear: Factory 15.09 lbs./GiroDisc 14.8 lbs.
It's not much lighter, at least in the rear (not even 1 lbs.). Since most of our cars are RWD I do not believe it make so much difference...
You can probably check the weights of the tires at Tirerack.com
#20
01-23-2010, 09:24 PM
At the risk of sounding self-serving, some good forged wheels will save you more than 30 lbs of UNSPRUNG weight.
You will feel the difference, big time.
You will feel the difference, big time.
#22
01-23-2010, 10:38 PM
Hey G-money, I copied the specs from the Porsche.com site here for you to use your calculator in terms of weight.
http://www.porsche.com/usa/models/91...s/?gtabindex=5
it's 88 lbs. 3,406 lbs vs 3,318 is 88 lbs. I guess it's possible that the PDK version vs. manual was not as heavy on my 997.1. Regarding PDK, I just couldn't see myself buying an automatic Porsche regardless of how much quicker the computer can shift.
http://www.porsche.com/usa/models/91...s/?gtabindex=5
it's 88 lbs. 3,406 lbs vs 3,318 is 88 lbs. I guess it's possible that the PDK version vs. manual was not as heavy on my 997.1. Regarding PDK, I just couldn't see myself buying an automatic Porsche regardless of how much quicker the computer can shift.
The website is wrong and BTW, it is not the only misprint on the site...
The PDK diff is 66lbs. Check the '09 brochure. For your example (pg 161):
'09 Carrera S Cab (Man/PDK) 3329lb/3395lb
Trust me... the PDK mass diff is a well known number among 911 fans.
And another thing... there was no PDK in your 997.1 series car. It is only available starting '09 997.2 models.
And re your 'put down' comment re PDK... to each his own. Some of us, repeat 911 owners, do know better, ya know? You seem to react with a certain animosity, when some of us try to deliver correct information.
Last edited by adias; 01-24-2010 at 12:34 AM.
#24
01-24-2010, 03:27 AM
The Tire Rack website lists all the tire weights. Once you search down to your car model and tire size, click on "specs" and you'll find the info you need.
#25
01-24-2010, 08:07 AM
Registered User
Join Date: Jul 2007
Location: Natick, MA
Age: 51
Posts: 3,122
Rep Power: 162 Hey G-money, I copied the specs from the Porsche.com site here for you to use your calculator in terms of weight.
http://www.porsche.com/usa/models/91...s/?gtabindex=5
it's 88 lbs. 3,406 lbs vs 3,318 is 88 lbs. I guess it's possible that the PDK version vs. manual was not as heavy on my 997.1. Regarding PDK, I just couldn't see myself buying an automatic Porsche regardless of how much quicker the computer can shift.
http://www.porsche.com/usa/models/91...s/?gtabindex=5
it's 88 lbs. 3,406 lbs vs 3,318 is 88 lbs. I guess it's possible that the PDK version vs. manual was not as heavy on my 997.1. Regarding PDK, I just couldn't see myself buying an automatic Porsche regardless of how much quicker the computer can shift.
So no matter how you try to 'reduce' your weight on a street car - it is useless. To get to weight number what makes some competitive difference you`ll need to really strip it down tearing apart practically entire interior, all panels and throw away passenger seat.
#26
01-24-2010, 08:25 AM
I forget the numbers, but I think PS2s were the lightest of the OEM tires. When I make modification decisions they are performance minded. I won't do anything for aesthetic reasons. So, when it comes to picking out new tires, I do look at things like weight because if one tire is 4 lbs lighter than another, I'll gravitate to it even if it's more expensive. Similar with Wheels - Right now I'm tracking with 18" Volks in 8.5 and 11" widths. Some tracking 997s will go to a 12" rear and I don't see the reason given 11 is the correct width for the 305s I run at the rear and the 11s are obviously lighter than the 12s. Forged lightweight and strong (and relatively inexpensive). With rotors I'd love to save a few lbs, but the cost is prohibitive. For some reason I just can't justify the cost even though I'm tracking what's basically a $100k car, so one would think "so whats a few k more for lighter solid rotors?" Go figure. Then again, I have another cycle left in my rear rotors (fronts will need to be replaced this spring), so maybe once front and rear both need replacing I might try the aftermarket floating rotors.
You have a good philosophy going - if you are going to tweak the car, might as well have weight in mind. But, unfortunately, weight isn't going to dramatically change the car.
You have a good philosophy going - if you are going to tweak the car, might as well have weight in mind. But, unfortunately, weight isn't going to dramatically change the car.
#27
01-24-2010, 08:50 AM
I asked couple of 911 cup car owners what is their weight and was told a number somewhat between 2600 to 2700 pounds.
So no matter how you try to 'reduce' your weight on a street car - it is useless. To get to weight number what makes some competitive difference you`ll need to really strip it down tearing apart practically entire interior, all panels and throw away passenger seat.
So no matter how you try to 'reduce' your weight on a street car - it is useless. To get to weight number what makes some competitive difference you`ll need to really strip it down tearing apart practically entire interior, all panels and throw away passenger seat.
#28
01-24-2010, 10:58 AM
Join Date: Dec 2009
Location: St. Petersburg, Florida
Posts: 803
Rep Power: 59
Understood, but as I wrote, I like to find out the what if's from people who know. I thought it might be possible to reduce the weight to get close to a coupe. However, it looks like that's not going to happen. Thanks for the information.
#29
01-24-2010, 11:35 AM
I ordered my car and yes I wanted PDK and I know it adds 66lb, but I made sure it had no Bose, no XM, and non-electric sports seats.
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