Crazy ideas
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cucurumbe
- Lude Dude
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Crazy ideas
Has anyone every tried or thought of building their own forced induction system. I kinda have been looking at specs for boost and atmospheric pressures. I looked at a turbo kit and it stated that it could move a maximum of 1100 cfm. I don't need or want that kind of boost. But a little more juice at pedal wouldn't hurt either. I was thinking about maybe a 4" vortec fan. They produce about 200 cfm and their electric.They also have a good history of lasting forever. What would be the dangers? Is it even feasible? Would it raise the cylinder temp. enough to where i would need to cool the intake air? Any input would be greatly appreciated!
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spiffyguido
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Re: Crazy ideas
If only it were that easy....
Lots of people have tried to build their own forced induction systems....it's been a staple of motorsport development for years. The concept is easy enough, but getting good results can be really difficult. Some of the brightest minds in motorsport spend their entire lives chasing forced induction power, and the technology has progressed a great deal over years past. If you look at modern Porsches with their variable geometry vane turbochargers, or you look at how basic superchargers are being applied reliably to entry level cars like the Cobalt, you can see how far we've come. How far have we come? Well, to put things in perspective, Porsche first dropped a turbo into the 911 in the 1970s, and their first couple models killed a lot of drivers because the boost was so unpredictable rendering the car very difficult to drive. Now, cars under boost have predictable, safe power....lots more of it than engineers ever would have dreamed of years ago.
I say this to point out that to build a good forced induction setup, you can literally stand on the shoulders of the engineering giants that have gone before you. The main methods of forced induction these days are: supercharger (roots, centrifugal, twin-screw type) and turbocharger. There is a ton of material out there suggesting how to do a good implementation of each kind. If you want to build forced induction, you need only to start reading.
Regarding your 4" inline electrical fan. Lots of people have tried to make this work, although I have yet to hear of anyone succeeding. The reason for their failure is due to something very simple. A simple fan that can move a lot of air only provides half of the forced induction equation. You mentioned cubic-ft-per-min, an important value. Yes, it is true that turbochargers and superchargers also are measured in cfm as well. The key to a supercharger or turbocharger though is not how much air it can move. A supercharger is not really a pump just meant to flow air, neither is a turbocharger. Superchargers and turbochargers work because they have a 'pressure-ratio'. The air they deliver is at a higher pressure than what they take in. Turbochargers accomplish this using incredibly high rpms to get air moving super fast and then slow it down. Centrifugal superchargers work this way as well. Roots and twin screw superchargers work by jamming a quantity of air into a smaller space than it was before.
It might seem like a simple fan in a pipe would be able to do something similar, and it does to a small extent, but the pressure rise will be very small because the pressure will always escape back out the fan. In short, an electric fan won't give you a meaningful power boost, and in all likelihood, it will slow you down.
I don't mean to discourage you. Chasing forced induction is probably one of the most enjoyable things you can do with a car. If you're looking for cheap, easy forced induction power, starting with a basic turbo is probably the easiest option, on a prelude anyway. If you decide to chase this type of power, learn the math first. Even small turbos can put up big numbers when they are well tuned. The same small turbo can also blow your engine to the high heavens if you don't meter fuel properly.
If you're looking for a good book to get you started, there are two books called "Turbocharged!" and "Supercharged!" that might help. They contain basic formulas and example installs. It's a good starting point. If you don't want to buy a book, there is also a lot of good info on the web.
Lots of people have tried to build their own forced induction systems....it's been a staple of motorsport development for years. The concept is easy enough, but getting good results can be really difficult. Some of the brightest minds in motorsport spend their entire lives chasing forced induction power, and the technology has progressed a great deal over years past. If you look at modern Porsches with their variable geometry vane turbochargers, or you look at how basic superchargers are being applied reliably to entry level cars like the Cobalt, you can see how far we've come. How far have we come? Well, to put things in perspective, Porsche first dropped a turbo into the 911 in the 1970s, and their first couple models killed a lot of drivers because the boost was so unpredictable rendering the car very difficult to drive. Now, cars under boost have predictable, safe power....lots more of it than engineers ever would have dreamed of years ago.
I say this to point out that to build a good forced induction setup, you can literally stand on the shoulders of the engineering giants that have gone before you. The main methods of forced induction these days are: supercharger (roots, centrifugal, twin-screw type) and turbocharger. There is a ton of material out there suggesting how to do a good implementation of each kind. If you want to build forced induction, you need only to start reading.
Regarding your 4" inline electrical fan. Lots of people have tried to make this work, although I have yet to hear of anyone succeeding. The reason for their failure is due to something very simple. A simple fan that can move a lot of air only provides half of the forced induction equation. You mentioned cubic-ft-per-min, an important value. Yes, it is true that turbochargers and superchargers also are measured in cfm as well. The key to a supercharger or turbocharger though is not how much air it can move. A supercharger is not really a pump just meant to flow air, neither is a turbocharger. Superchargers and turbochargers work because they have a 'pressure-ratio'. The air they deliver is at a higher pressure than what they take in. Turbochargers accomplish this using incredibly high rpms to get air moving super fast and then slow it down. Centrifugal superchargers work this way as well. Roots and twin screw superchargers work by jamming a quantity of air into a smaller space than it was before.
It might seem like a simple fan in a pipe would be able to do something similar, and it does to a small extent, but the pressure rise will be very small because the pressure will always escape back out the fan. In short, an electric fan won't give you a meaningful power boost, and in all likelihood, it will slow you down.
I don't mean to discourage you. Chasing forced induction is probably one of the most enjoyable things you can do with a car. If you're looking for cheap, easy forced induction power, starting with a basic turbo is probably the easiest option, on a prelude anyway. If you decide to chase this type of power, learn the math first. Even small turbos can put up big numbers when they are well tuned. The same small turbo can also blow your engine to the high heavens if you don't meter fuel properly.
If you're looking for a good book to get you started, there are two books called "Turbocharged!" and "Supercharged!" that might help. They contain basic formulas and example installs. It's a good starting point. If you don't want to buy a book, there is also a lot of good info on the web.
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cucurumbe
- Lude Dude
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- Joined: Sun Feb 15, 2009 9:55 am