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    1999 Porsche 911 C2
  1. If that were the case using 8%, my car with the mods would only have about 285hp at the crank. That would be a decrease of 11 horsepower, rather than an increase of 14 horsepower. With headers, exhaust and intake, I don't believe 8% is correct.
  2. Well you know, I'm just trying to get an accurate crank horsepower after my dyno trip. :P
  3. I have had several discussions about crank horsepower vs Rear wheel horsepower. I wanna got more opinions form the Porsche board. Mostly from what I have read, most people assume a 15% loss from the crank to the tires. For this calculation, you would mutiply the crank horsepower by .85 Example. A 300 horsepower 911 has (.85)*300 = 255 wheel horsepower. Now, the person who dynoed my car says he multiplys 1.15 to the wheel horsepower. This is not the same. Example. 255*(1.15) = 293.25 crank horsepower I also looked at the TPC Supercharger website. They also use the 1.15 m
  4. Any suggestions on width size? I'm planning on 7mm in the front, and 14mm in the rear. Does it really look bad going larger than that in the rear?
  5. I'm in the process of purchasing some wheel spacers. I know the correct size for the extended bolts. I have noticed on the H&R spacers it says the original cone washers must be reused. I pulled off an original bolt to look at these cone washers. The bolt has a ridge that prevents the cone washers from coming off. How do you get these off to reuse them? Grind the ridge down? Or, if I purchase the extended bolts, will they already have the cone washers? I'm having a hard time finding the extended bolts. I need 52mm and 60mm. Any suggestions? Thanks!!
  6. Funny you should ask. I just emailed them about their dyno. If you go to the fabspeed website, look under 996, and then the Fabspeed exhaust, it showed a stock run of 218.2 hp, and then 234.7 ftlbs after the exhaust. (Awfully low, must be a weird dyno). This would be a 16.5 hp gain and 8.7 ftlbs of torque. But in their adertisement, they claim 8-12 hp gain with 10 ftlbs of torque. I believe the 8-12 to be right. I also have the Fabspeed intake and JVT headers. Since I never did a base line run, I assumed 252 factory hp with 218 ftlbs of torque at the wheels. My results were 10.9 hp
  7. I talked the dyno operator about temperature. Here was his reply. " The dyno used the SAE correction which corrects to STP, standard temperature and pressure. Standard temp is 70F. I don't know the pressure. Even with the correction factor, cars will usually make a little more power in cold weather." FYI
  8. The operator was on his computer doing his thing. I know after two runs after driving an hour in the heat, the numbers were consistently 7HP lower. After it sat for 15 minutes with fans blowing on the engine, and radiators up front, that's when I got the better result. Well that sounds about right. 262.9hp vs 252hp, and 233.5 torque vs 218. Headers, Fabspeed exhaust, and Fabspeed intake is probably the difference. Anyone know why the drop of HP around 5300 RPM, and the spike back up at shortly after? The 993 stock dyno I saw pretty much did the same thing at a different RPM.
  9. Well I did my first dyno today. I have a 99 model C2 911 with 42,500 miles. I have done 3 mods. I have the fabspeed intake, fabspeed exhaust, and JVT headers. I drove about an hour to the dyno shop so naturally the porsche was hot. The best of my first two runs were 256.0HP at the wheels, with 222.3 ftlbs of torque. After letting the engine cool down with some fans, I did a third test. This yielded 262.9HP at the wheels and 233.5 ftlbs of torque. The temperature was just over 80 degrees. Now assuming a standard day of 58 degrees, I'm sure the results would have been higher. Any
  10. I have a 99 C2 911. My current mods are the Fabspeed intake system, Fabspeed exhaust, and JVT Racing headers. I hope to head to the dyno in a few days. Does anyone have a stock 996 dyno graph? Also, what is the conversion factor from wheel horsepower/torque to the crank horsepower/torque? I'll post the results with these mods. Since I never did a dyno while bone stock, I"m not sure what to compare it to. That's why I need a stock dyno. Also, can I put spacers on my 18" turbo twist wheels to have a wider look? If so, where can I find these? Thanks.
  11. 5. "Spacers, 17mm rear and 7mm fronts ("wider is better", and looks a lot better)" Where do you get these spacers? So I take it, they can be used to space the 18" turbo twist wheels? Thanks
  12. More corrosive than gasoline and all the additives in it? Aceton burns very cleanly just like propane. Supposedly, fuel systems are designed to withstand any corrosive materials..
  13. I've been reading about adding acetone to your gas helps vaporize the gas more efficiently. Supposed 2-3 oz's per 10 gallons does wonders. Supposedly there aren't any side effects, and it also reduces hydrocarbons. I wonder if anyone has done this before. I'll try this in my Nissan truck before giving the 911 a dose.. Here is a great article.. http://www.pureenergysystems.com/news/2005...900069_Acetone/
  14. Does anyone know the piping size on stock headers? Thanks
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