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One thing you might know well but wanted juts to point out, you will have soon issues with the gearbox (aka. the 3rd gear, the stock 3rd gear just can't take the beating with your torque, maybe it will handle one season, but be prepared for update! One tip here, after doing basic rebuilds for my box (because of 3rd gear) for too many times, I accidentally found a nice cheap new 997TT box, and am very happy - never hear 997TT folks talking about 3rd gear problems and the shorter gearing of 997TT box compensates for my larger rear tire and now have basically stock gearing). Sure installing the GT2RS stuff there is best, but by buying a 997TT box I was back on track in no time.
A great thread I have totally missed because only browsing the GT3 forum and Racing forums here.
Nice to see more people getting on with the 996TT track crack pipe....
Could you tell about the weight savings with the dash? Obviously with Motec etc difficult to say.
Thanks Kaizu and great to see your track monster still alive! The pictures are awesome as well.
Regarding the dash, it knocked out a large chunk of weight and the carbon only weighs a couple pounds.
The stock dash below that is stripped of accessories weighs ~14lbs and the gauge cluster is around ~4lbs. I'm guessing the rest of plastic crap, climate control and stereo stuff is another ~20lbs but most of it is in the trash now
Current weight of the car is ~3011lbs with no driver or fuel. That number will drop a bit since the A/C, P/S and heavy exhaust are getting removed.
On a side note, we have more progress on the engine and the coolant pipes will never come out now.
Steve, don't understand why people tell CF roof is dangerous, I was the first guy to come and save my good buddy after he rolled his (similar type of) 996 badly with CF roof, the roof helped there a lot, he only had a roll bar in the car. And please have a look at all the BMW M models that have CF roof directly from the factory.
Greetings from Europe,
Hi Kai,
This topic came up numerous times in the last years with track guys here in my area and in forums (including here) and I've spoken to a good friend who's an engineer and works with composites.
Carbon roof panels for a street car have 2 major drawbacks:
- they are generally not homologated for street use (crash tested) and are often not manufactured to standards with which a crash test could be passed (and price is not an indicator). Carbon can splinter into sharp spears. This is not so much an issue with trunk lids or hoods, but a roof panel... Even my 997 GT2 folding carbon buckets have a layer(s) of fiberglass/kevlar on the inside for exactly this reason. And if you start adding additional layers to the roof panel, you will likely end up just as heavy as the steel panel. My aftermarket carbon trunk lid is very close to exactly as heavy as the OEM 997 aluminum trunk lid. But it has additional coolness
- the 996 body was not designed for a carbon roof panel. Generaly, the mounting flanges for carbon will be designed especially to ensure a good bond and a transfer of loads through the panel to retain the body's rigidity. A car designed from the factory for carbon panels will be designed with this in mind.
With a full cage, these concerns become mostly moot. But for a street 996, I'd choose a steel panel. Thankfully I am not faced with any issues here as my car came from the factory without a sunroof. And your friends roof not having any issues in one accident is a bit like the 80 year old who's smoked 2 packs a day for 65 years.
Great pics. I love the last pic! We should do a European meet up at the ring sometime.
Originally Posted by Scawt
Current weight of the car is ~3011lbs with no driver or fuel. That number will drop a bit since the A/C, P/S and heavy exhaust are getting removed.
Wow. You're raising the bar. You have to find 11lbs more, though. Get a 2 in front of the weight on a 996tt and you will have people taking notice!
Hi Kai,
This topic came up numerous times in the last years with track guys here in my area and in forums (including here) and I've spoken to a good friend who's an engineer and works with composites.
Carbon roof panels for a street car have 2 major drawbacks:
- they are generally not homologated for street use (crash tested) and are often not manufactured to standards with which a crash test could be passed (and price is not an indicator). Carbon can splinter into sharp spears. This is not so much an issue with trunk lids or hoods, but a roof panel... Even my 997 GT2 folding carbon buckets have a layer(s) of fiberglass/kevlar on the inside for exactly this reason. And if you start adding additional layers to the roof panel, you will likely end up just as heavy as the steel panel. My aftermarket carbon trunk lid is very close to exactly as heavy as the OEM 997 aluminum trunk lid. But it has additional coolness
- the 996 body was not designed for a carbon roof panel. Generaly, the mounting flanges for carbon will be designed especially to ensure a good bond and a transfer of loads through the panel to retain the body's rigidity. A car designed from the factory for carbon panels will be designed with this in mind.
With a full cage, these concerns become mostly moot. But for a street 996, I'd choose a steel panel. Thankfully I am not faced with any issues here as my car came from the factory without a sunroof. And your friends roof not having any issues in one accident is a bit like the 80 year old who's smoked 2 packs a day for 65 years.
I apologize the thread starter for this off-topic, but excuse me, Steve "has talked with track guys in his area" and that is better information than the vast increase of cars that are available with carbon fiber roof directly from the factory and are legislated and crashtested and everything?
Before putting your expert hat on, you could study how the roof panel is installed in these cars and what is its function.
When you are able to compare carbon fiber panel, steel panel, and a sunroof panel, you will understand the steel panel is the more dangerous one. And the sunroof one is the most dangerous one.
Have never heard about a shattered CF roof panel. Seen plenty of CF roof rollovers as I spend majority of my free time at race track events. The one roll example I told was interesting, as it was my best friend who did it just in front of my eyes with a similar car at a really high speed. And, in a case the CF roof shatters, it has provided already a massive support for the impact and has done its job better than a steel panel.
M3 CSL started the trend back in 2003 and now they are in many cars. From a luxurious M6 to a track toy Viper ACR. By the way, BMW i3 is an example how with a carbon fiber roof etc. they have got rid of the b-pillar of the car and it's still safe.
Originally Posted by Scawt
Current weight of the car is ~3011lbs with no driver or fuel. That number will drop a bit since the A/C, P/S and heavy exhaust are getting removed.
Nice. It will go low indeed For a reference, my car in "street setup" without fuel is ~3050lbs, with so much to do but where should one stop.. A friend has a one that is substantial lighter with all the CF body panels one can get, with similarly interior still in place (Willy077 here in the forums), but I think that car is still under construction and not sure on its final measured weight figure.
I apologize the thread starter for this off-topic, but excuse me, Steve "has talked with track guys in his area" and that is better information than the vast increase of cars that are available with carbon fiber roof directly from the factory and are legislated and crashtested and everything?
Before putting your expert hat on, you could study how the roof panel is installed in these cars and what is its function.
hefty reaction!
Kai, I had just wanted to illustrate that this is not a topic that is rarely discussed. My primary source of information on composites is an old friend who works mainly with composites in the automotive industry. he works on race cars and his company is an OEM supplier. As such, his opinion is generally more conservative than many aftermarket companies, but he was not at all in favor of a composite roof panel in a street car without a full cage.
And as far as looking at the body of a 996 and how it is constructed: I think I have looked at this much more closely than 95% or more here on the board. Trust me, I know exactly how a 996 she'll is put together and I know most of the differences to a 997 shell. And I know exactly how the roof panel is mounted.
Originally Posted by Kaizu
When you are able to compare carbon fiber panel, steel panel, and a sunroof panel, you will understand the steel panel is the more dangerous one. And the sunroof one is the most dangerous one.
Have never heard about a shattered CF roof panel. Seen plenty of CF roof rollovers as I spend majority of my free time at race track events. The one roll example I told was interesting, as it was my best friend who did it just in front of my eyes with a similar car at a really high speed. And, in a case the CF roof shatters, it has provided already a massive support for the impact and has done its job better than a steel panel.
As I tried to say the first time, OEM has almost nothing to do with aftermarket in this particular case.
And I am very curious how you think the steel panel is worse on the 996. Especially after studying the construction of the roof...
I never said I was an expert (and I don't have any expert hats-at least not in composites). But I did research on this topic because I wanted to know what works and what doesn't before spending money and time. And I was simply relaying the results of my research.
Yep no worries mate, I understand this is a bit of gut feeling discussion, but seen people blaming CF roofs too many times around the neighbor forum 6SPO etc. while the automotive industry is going to another direction with great success since M3 CSL, now BMW i3 etc.
My provocative note about CF roof being superior to steel roof was about it taking the impact. Theoretical, but I would rather have my CF roof take the initial impact of huge force rather than a steel panel.
Back to on topic, nice work with the doors there Scawt! While John said not really savings to be made with CF doors in your case, I think they still could be worth the effort if you get a nice deal somewhere, however no point paying big money.
Unlike the 997, 996 has steel and not alu doors, so better have eyes open when racing teams sell their spares, there might be good deals of CF Cup doors available. Here's Mooty's view about the weight of CF race doors vs gutted OEM doors: https://rennlist.com/forums/996-gt2-...l#post10249970
No worries guys, good to see the technical discussions!
I stopped at Rothsport today to pickup some of my old parts and got some teaser shots of the engine while it was on the stand. The trans is about to be cracked open so hopefully we don't have any costly surprises inside
Engine looks naked without the A/C, power steering and air injection. Glad to get some more weight off the *** end
I'm doing the electric cup steering pump up front as well; how are you connecting the fluid to the steering rack? I don't think there are fittings that mate up correctly is a weird thread pattern
Thanks for that link.. I have searched and save so many threads on the conversion, and somehow missed that one. Let me know how it goes and how you mount the pump... I would ask for advice on pulley/belt, but I'm not quite sold on the AC delete since I tend to park my DD and drive the Porsche more during summer.
Are you running the version with the overflow canister or without? My pump didn't come with one and I think I am going to adapt one based on some reading I've done, and how the later 997 cups all seem to have it.
I'd love to chat sometime about your build. I imagine we will cross paths at a DE one day based on your location depending on how far you travel
10-09-2016, 12:36 PM
And your friends roof not having any issues in one accident is a bit like the 80 year old who's smoked 2 packs a day for 65 years. 
A friend has a one that is substantial lighter with all the CF body panels one can get, with similarly interior still in place (Willy077 here in the forums), but I think that car is still under construction and not sure on its final measured weight figure.
