991.2 GT3 lightweighting project
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ncflat6 (10-01-2023)
07-08-2018, 07:33 AM
#17
Instructor
^^^ seriously. Set straight a widely disseminated Rennlist belief taken as truth for years on various PCCB vs. steel threads.
OP, if you’re that concerned with weight, do all the above and switch out your LEDS for halogens. If you’re going LEDS, it’s a cosmetic thing and it’s costing you more weight than a CF hood, roof, and rear glass will save you combined.
Im sure you can sell/swap the LEDS here on RL.
Id say remove the FAL, but you might actually need that where you are. FALs are the only thing that adds weight on my GT3 from factory (I even have the smaller tank) and I may just have them removed along with the Radio/speakers and stored for resale as I never use them.
OP, if you’re that concerned with weight, do all the above and switch out your LEDS for halogens. If you’re going LEDS, it’s a cosmetic thing and it’s costing you more weight than a CF hood, roof, and rear glass will save you combined.
Im sure you can sell/swap the LEDS here on RL.
Id say remove the FAL, but you might actually need that where you are. FALs are the only thing that adds weight on my GT3 from factory (I even have the smaller tank) and I may just have them removed along with the Radio/speakers and stored for resale as I never use them.
07-08-2018, 09:20 AM
#18
SJW, a Carin' kinda guy
Rennlist Member
Rennlist Member
I agree on LED v. Xenons. It is fairly substantial. Like 12-14lbs or something.
That’s negative money and weight savings.
I would do the lightweight glass before I did the carbon hood. The hood and fender are pushing $50k by the time you get them painted and installed (and the ever present paint match issues). The rear glass is $2300 and the sides are $1700.
https://www.suncoastparts.com/produc...RSRWINDOW.html
The rear is the big chunk of the weight, 6lbs, you might save a pound and change each with the sides so I would skip them and just do the rear. The rear glass is up high and in the rear so it is an optimal place to save weight. I hope at some point to find someone with a 911T who ends up disliking the lightweight glass and trade as $4k is a bit much for me. I will rear out the interior first as it will remind me of my British junk. ;-)
That’s negative money and weight savings.
I would do the lightweight glass before I did the carbon hood. The hood and fender are pushing $50k by the time you get them painted and installed (and the ever present paint match issues). The rear glass is $2300 and the sides are $1700.
https://www.suncoastparts.com/produc...RSRWINDOW.html
The rear is the big chunk of the weight, 6lbs, you might save a pound and change each with the sides so I would skip them and just do the rear. The rear glass is up high and in the rear so it is an optimal place to save weight. I hope at some point to find someone with a 911T who ends up disliking the lightweight glass and trade as $4k is a bit much for me. I will rear out the interior first as it will remind me of my British junk. ;-)
07-08-2018, 09:35 AM
#19
Admittedly, the LED choice is entirely driven by aesthetics and irrational fetishism over lighting technology.
Hey, I never said I would do anything to save weight.
By the way, the rear glass for the 3RS.2 and T is not that expensive. I believe it is $1,000 - 1,500 USD. It is not the same part as the plexi version on Suncoast's website, which costs signifcantly more.
Hey, I never said I would do anything to save weight.
By the way, the rear glass for the 3RS.2 and T is not that expensive. I believe it is $1,000 - 1,500 USD. It is not the same part as the plexi version on Suncoast's website, which costs signifcantly more.
07-08-2018, 09:54 AM
#21
SJW, a Carin' kinda guy
Rennlist Member
Rennlist Member
Admittedly, the LED choice is entirely driven by aesthetics and irrational fetishism over lighting technology.
Hey, I never said I would do anything to save weight.
By the way, the rear glass for the 3RS.2 and T is not that expensive. I believe it is $1,000 - 1,500 USD. It is not the same part as the plexi version on Suncoast's website, which costs signifcantly more.
Hey, I never said I would do anything to save weight.
By the way, the rear glass for the 3RS.2 and T is not that expensive. I believe it is $1,000 - 1,500 USD. It is not the same part as the plexi version on Suncoast's website, which costs signifcantly more.
Do you have part numbers or a link to the T/3RS.2 glass? For $1500 I would do the rear window as I dislike the defroster lines and find them distracting.
Peter Stout commented on the T glass in his review of the T and GT3 touring thread.
07-08-2018, 10:00 AM
#23
SJW, a Carin' kinda guy
Rennlist Member
Rennlist Member
Add lightness. Saving weight makes a car faster everywhere. Ounces add up to pounds and you can feel the difference.
07-08-2018, 10:15 AM
#24
Also, like I said earlier, the RS isn't as light as a manual GT3. So, if you want something nimbler, lighter on its toes, more reactive, etc., the GT3 actually makes more sense as a starting point.
07-08-2018, 10:39 AM
#25
Although neither I, nor any engineer I know who has a real knowledge of Porsche naturally aspirated engines has ever been convinced that, all things being equal (i.e., exactly the same car, the same conditions, the same scope of and type of exhaust system components) any one aftermarket design exhaust system produces any more HP than any other system (other more by, perhaps 3 to 5 HP), there can, however, be differences in weight, durability and overall quality.
Having not been satisfied with any of the more than 100 exhaust systems at which I have looked, I have decided to build one. Though I doubt it will be ready until the end of the first quarter of 2019, and I know it will be expensive (probably $25,000 or more), I hope it will be better made and lighter than anything currently available. It will also try certain manufacturing technology which should (at least in theory) increase the flow of air though the pipes. What I do not know yet is how durable it will be because parts of it (e.g., side mufflers, final muffler, certain pipes, etc.) will be made of titanium (though approximately 40% lighter than steel, titanium does not withstand heat nearly as well as steel). The headers, however, will be made from Inconel. Additionally, depending upon where a car is operated and legal conditions, each and every component will be easily and infinitely replaceable with pipes. Do not know the final result in spite of much CAD and CFD work, but I'll find out.
Having not been satisfied with any of the more than 100 exhaust systems at which I have looked, I have decided to build one. Though I doubt it will be ready until the end of the first quarter of 2019, and I know it will be expensive (probably $25,000 or more), I hope it will be better made and lighter than anything currently available. It will also try certain manufacturing technology which should (at least in theory) increase the flow of air though the pipes. What I do not know yet is how durable it will be because parts of it (e.g., side mufflers, final muffler, certain pipes, etc.) will be made of titanium (though approximately 40% lighter than steel, titanium does not withstand heat nearly as well as steel). The headers, however, will be made from Inconel. Additionally, depending upon where a car is operated and legal conditions, each and every component will be easily and infinitely replaceable with pipes. Do not know the final result in spite of much CAD and CFD work, but I'll find out.
07-08-2018, 10:45 AM
#26
Three Wheelin'
3150lbs 2019 gt3rs
3153lbs 2018 pdk GT3
3116lbs 2018 Manual gt3
Not sure if the weight listed for the RS included magnesium wheels.
Either way, your weight with LEDs 12-14lbs and FAL10-13lbs puts you back to relatively close to pdk territory. A burrito and a couple beers could put your over
07-08-2018, 11:00 AM
#27
I see these numbers posted for the cars
3150lbs 2019 gt3rs
3153lbs 2018 pdk GT3
3116lbs 2018 Manual gt3
Not sure if the weight listed for the RS included magnesium wheels.
Either way, your weight with LEDs 12-14lbs and FAL10-13lbs puts you back to relatively close to pdk territory. A burrito and a couple beers could put your over
Hmm. If the advertised RS weight is with Weissach package and magnesium wheels, that would make the manual GT3's weight advantage even more pronounced. Anyone know for sure?
07-08-2018, 11:04 AM
#28
Three Wheelin'
weissach -14lbs
Magnesiun wheels -25
all in, a RS could be 3,111
07-08-2018, 11:12 AM
#29
SJW, a Carin' kinda guy
Rennlist Member
Rennlist Member
Porsche always quotes weight as lightest spec. So the GT3RS.2 includes WP with Mag wheels and AC and Radio delete. A GT3 never had AC delete, and radio delete may or may not have been included in the weight as it was not available when the weight was announced. I suspect it is not accounted for in the 3116lbs number based on published weights for the 911R and the differences between the GT3 and the 911R.
07-08-2018, 12:40 PM
#30
This is where I had seen the 1:6 ratio before:
Back in 2009, Olaf Manthey during an interview in Excellence said: “Removing 33 pounds of unsprung weight at the wheels is equivalent to losing 198 pounds from the body of the car, as a 1:6 factor has to be applied when the car is moving and that weight becomes mass. In fact, we are conservative with the 1:6 ratio, as Porsche considers it to be 1:7.”
Interesting thread discussion here: https://rennlist.com/forums/997-gt2-...agazine-3.html
Still, I was much more familiar with a 1:4 ratio regarding wheels. But I guess it really depends on the rotational/moment of inertia.
Back in 2009, Olaf Manthey during an interview in Excellence said: “Removing 33 pounds of unsprung weight at the wheels is equivalent to losing 198 pounds from the body of the car, as a 1:6 factor has to be applied when the car is moving and that weight becomes mass. In fact, we are conservative with the 1:6 ratio, as Porsche considers it to be 1:7.”
Interesting thread discussion here: https://rennlist.com/forums/997-gt2-...agazine-3.html
Still, I was much more familiar with a 1:4 ratio regarding wheels. But I guess it really depends on the rotational/moment of inertia.