Quote:
Originally Posted by TIM.G 911
Super charger takes horsepower to make horsepower. Turbo charging is free horsepower.
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This is a myth. Do your research. Back pressure and cam timing of turbo engines use horsepower or in actuality prevent flow therefore using some potentially "free" hp. The exhaust side of a turbo motor always has higher pressure from the intake side so you have to have very little valve overlap. And obviously higher pressures to charge the turbo is naturally a bad thing. The fact that can't be denied is turbos are more efficient because they use energy or heat that otherwise would be wasted to drive a compressor. On the other hand a good supercharger doesn't use much hp to get to max boost. For example an eaten 62 only uses 15-25hp MAX at 1200 rpms with a 2:1 overdrive. this compressor can easily get you 300-350 hp.
Like others have said, what are the driving characteristics you are looking for? If you are going with an older turbo don't expect boost to come on until 3500 to 4000 rmps unless you can afford a variable geometry turbine turbo (good luck with $2,500). With a SC you get instant boost and you also don't have to rev the engine as high. Actually, it's better to not rev the engine as high and save money on expensive valve drive components. It's all about what you want. I like SCs and turbos but I'm building a SC motor for the low cost solution and high low-end torque curve of a roots blower.
There's also the other myth that porsche doesn't do SCs from the factory. They just started putting them on their V6 cayennes if I remember correctly. Do a search and you will see what I'm talking about.
The best advice I could give you is to read a few books before you boost your car with either method. This is good advice. Also see what others have done and what actually works. Turbos are obviously tried and true, but I would rather have a good SC system than a sh* tty turbo system, and a 79SC with the larger ports and lower compression is set up well for boost. Also, the timing isn't the best, but it is pretty good and will work. I have documents I can send on some kits from SoK that were sold (tried and true). I also have info from TurboKraft and others. I'm also a mechanical engineer. Let me know if I can help.