Any front and rear downforce data?
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Anyone's thoughts on the effects of external wastegate dump tubes blowing exhaust under the rear of the car, by the crank case halves. Negligible or possible extra lift on the back at top speed and open wastegates?
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Actually if setup right it would help down force. F1 had blown diffusers for a bit for an increase in downforce but like everything else cool to ever happen in f1, they banded it.
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Ok, if that's the case I don't think mine are set up right to help. I didn't want to attract too much attention to the car so I installed small diffusers on the ends of the dump tubes, quiets them down and they have no back pressure. But now the exhaust is dispersed in a 360 degree pattern, not strait out.
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If you are running a GT2 bumper cover (or replica), you will need the flip and angle the center radiator forward along with the proper ducting to divert air out over the front hood thus creating down force. Without this, the front bumper is just for show and aerodynamically useless.
Here are pics of the 997GT3 rear under tray on my car. It has NACA ducts (purchased separately) that clip into it and divert air to the rear brake calipers via air guides (also purchased separately) that attach to the rear thrust arms. All factory OEM parts.
Rear 997GT3 under tray: 997 504 629 92
Rear 997GT2 brake NACA ducts: 997 575 183 00 and 997 575 184 00
Rear 997GT3 brake air guides: 997 331 487 02 and 997 331 488 02
Rear 997GT3RS brake rotor ducts: 997.575.531.90 and 997.575.532.90
Rear 997GT3RS brake duct clips 997.575.631.91 and 997.575.632.91 (these are for the PMNA cup arms - smooth finish. There are other clips that fit the textured OEM cast arms)
Brake duct screws (4 total needed) 999.073.516.01
You will need to do a little modding to make the rear 997 attach properly on the 996. The center attachment points are the same on both car but the end attachment points do not match. I ended up cutting the ends off of both trays and riveted the 996 ends onto the 997 tray. It's a perfect fit but you need to make accurate measuring and cutting to make it fit right. In my case I also added a scoop to the 997 tray to divert air to the transmission cooler which is directly above it (a 996TT does not have this obviously). You will also need to trim the rear fender liner to allow the back of the NACA duct to be exposed.
I also added 997.2GT3 LCA brake ducts which divert air to the rear brake rotors. These are superior to the 996GT2 ducts but will require adjustable drop links for perfect clearance. The 996GT2 ducts, while not as effective, will be easier to fit without much hassle.
997GT3 under tray. Note the NACA duct and the rivets where the 996 ends were spliced
[url=https://flic.kr/p/ezQFJw]
NACA duct exit. Note the trimmed fender liner and the air guides attached to the thrust arm
[url=https://flic.kr/p/ezMrvv]
997GT3RS rear brake ducts. The smaller GT2 heat shield needs to be trimmed further for these ducts. Note the 997Cup caliper studs.
[url=https://flic.kr/p/p4vRKB]
Rear view of the 997GT3RS brake duct. The attachment bracket is visible. Note the 997Cup toe arm.
[url=https://flic.kr/p/oMH2A5]
Here are pics of the 997GT3 rear under tray on my car. It has NACA ducts (purchased separately) that clip into it and divert air to the rear brake calipers via air guides (also purchased separately) that attach to the rear thrust arms. All factory OEM parts.
Rear 997GT3 under tray: 997 504 629 92
Rear 997GT2 brake NACA ducts: 997 575 183 00 and 997 575 184 00
Rear 997GT3 brake air guides: 997 331 487 02 and 997 331 488 02
Rear 997GT3RS brake rotor ducts: 997.575.531.90 and 997.575.532.90
Rear 997GT3RS brake duct clips 997.575.631.91 and 997.575.632.91 (these are for the PMNA cup arms - smooth finish. There are other clips that fit the textured OEM cast arms)
Brake duct screws (4 total needed) 999.073.516.01
You will need to do a little modding to make the rear 997 attach properly on the 996. The center attachment points are the same on both car but the end attachment points do not match. I ended up cutting the ends off of both trays and riveted the 996 ends onto the 997 tray. It's a perfect fit but you need to make accurate measuring and cutting to make it fit right. In my case I also added a scoop to the 997 tray to divert air to the transmission cooler which is directly above it (a 996TT does not have this obviously). You will also need to trim the rear fender liner to allow the back of the NACA duct to be exposed.
I also added 997.2GT3 LCA brake ducts which divert air to the rear brake rotors. These are superior to the 996GT2 ducts but will require adjustable drop links for perfect clearance. The 996GT2 ducts, while not as effective, will be easier to fit without much hassle.
997GT3 under tray. Note the NACA duct and the rivets where the 996 ends were spliced
[url=https://flic.kr/p/ezQFJw]
NACA duct exit. Note the trimmed fender liner and the air guides attached to the thrust arm
[url=https://flic.kr/p/ezMrvv]
997GT3RS rear brake ducts. The smaller GT2 heat shield needs to be trimmed further for these ducts. Note the 997Cup caliper studs.
[url=https://flic.kr/p/p4vRKB]
Rear view of the 997GT3RS brake duct. The attachment bracket is visible. Note the 997Cup toe arm.
[url=https://flic.kr/p/oMH2A5]
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can you flip and tilt the center radiator without doing a ton of other work? I ask because I'm in the process of a PP GT2 bumper and I'm replacing that radiator anyway. I don't want to go through the cost of going full functional front end, but if doing the radiator one off would give the biggest bang to aerodynamics without costing much, I'd consider that route.
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http://www.autoatlanta.com/porsche-p...section=105-17
http://www.autoatlanta.com/porsche-p...section=802-02
parts 5,13,9,11,12 just to see a few
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Thanks. Bumper only should be fine for street and occasional track days, right? Let me rephrase: doing the cosmetic only wont reduce my cooling ability from a stock turbo bumper, correct?
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Originally Posted by Dan m
Thanks. Bumper only should be fine for street and occasional track days, right? Let me rephrase: doing the cosmetic only wont reduce my cooling ability from a stock turbo bumper, correct?
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Some downforce info here: http://rennkit.com/why-factory-set-fails/ (I collect data...engineer thing...)
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You aren't going to get any blown diffuser effect from a dumped wastegate no matter how it is done unless it is being directed into a functional diffuser designed around taking advantage of the effect of the exhaust.. So it really doesn't matter how you have it dumped..
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Originally Posted by SeattleTurbo
You aren't going to get any blown diffuser effect from a dumped wastegate no matter how it is done unless it is being directed into a functional diffuser designed around taking advantage of the effect of the exhaust.. So it really doesn't matter how you have it dumped..