Random cai question..
05-29-2002, 07:07 AM
#13
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QUOTE
BV1:
There is no difference between 4" pipe and open air. You will not lose power due to throttle repsonse by going with a large pipe, your throttle response will actually be better because there is less initial restriction.
Not quite true. There is a significant loss when going from a larger area pipe to a smaller one, you can think of it as being turbulence created as the airflow converges on itself and tries to all speed up at once. The bigger the change, the larger the loss. There are ways to mitigate these effects that are commonly used, but getting fittings like those off the self of your auto parts or hardware store shelves is unlikely. Using a pipe that is not excessively large is the better option where you only have a short upstream run.There is no difference between 4" pipe and open air. You will not lose power due to throttle repsonse by going with a large pipe, your throttle response will actually be better because there is less initial restriction.
Given enough time and effort I could derive an example from the Bernoulli equations, but I have neither right now tongue.gif
05-29-2002, 07:08 AM
#14
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Vehicle: 01 Tiburon
Great engine bay i have to say..Well done maan..very nice look.
I cant see your filter at that position sad.gif BTW are these connectors made of silicone??
I cant see your filter at that position sad.gif BTW are these connectors made of silicone??
05-29-2002, 07:13 AM
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i have 2.75" flexable exhaust tubing i got it from wurk..one company i know that sells it. go to flexaust.com its a company that we use but i dunno if you can get it due to the fact that your not a distributor or what not the most you cpuld do is ask for a quote and see if they will sell it to you..im unsure about price my piece came from a remnent in the warehouse
05-29-2002, 06:09 PM
#16
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Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
Electrichead:
Thanks for the hookup. If nothing else, I'll see if SR can sign up as a distributor, then everyone could get access to that pipe!
EDIT:
I just checked out all their products. 99% of them have too much internal ribbing, they will seriously hurt air flow. The best I could find was the 'HT' product. I hope that is what you ordered.
Thanks for the hookup. If nothing else, I'll see if SR can sign up as a distributor, then everyone could get access to that pipe!
EDIT:
I just checked out all their products. 99% of them have too much internal ribbing, they will seriously hurt air flow. The best I could find was the 'HT' product. I hope that is what you ordered.
05-30-2002, 01:05 AM
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I have been pondering this thought for a while and would like some input on it. I know the idea works for wind tunnels and was wondering if it worked for CAIs on cars too.
It is a known fact that the largest wind tunnels rely a lot on their intake design to achieve maximum velocity. They do this by having a very large opening which then gently narrows. At the same time they generally bend at about a 45 degree angle to help speed up the air. So, in my thoughts, the best CAI you could make would start out with a large opening and then gently decrease to the size of the throttle body. Bends in the CAI should also be made in different at different diameters in the tubing to achieve less turbulence and maximum flow.
So to start off with a 4 inch pipe that narrows to 2.5, in theory, should perform well?
Does this theory hold true to cars or am I way off on this?
It is a known fact that the largest wind tunnels rely a lot on their intake design to achieve maximum velocity. They do this by having a very large opening which then gently narrows. At the same time they generally bend at about a 45 degree angle to help speed up the air. So, in my thoughts, the best CAI you could make would start out with a large opening and then gently decrease to the size of the throttle body. Bends in the CAI should also be made in different at different diameters in the tubing to achieve less turbulence and maximum flow.
So to start off with a 4 inch pipe that narrows to 2.5, in theory, should perform well?
Does this theory hold true to cars or am I way off on this?
05-30-2002, 02:46 AM
#19
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It's a fairly good theory--the whole thing about the 45° curve is from intake port design, they have to curve in usually due to engine layout and a smooth transition like that works well.
Either a curve, or if straight then a converging nozzle (think of a trumpet's horn, in reverse) works well to reduce flow losses and gradually increase velocity. Actually the best flow can be obtained from a converging-diverging nozzle--the flow path would widen slightly after the tightest point, creating a venturi effect. Most throttle bodies these days are actually a converging-diverging design.
The problem with this is actually building it--unless you have a spare baritone sitting around I don't see where you're going to get the piping from. To have it fabricated nicely, well I can see it very quickly running up over $500, even using something like plastic sheeting would be a few hundred by the time you got it sufficiently sturdy and insulated. And then you have to find a filter for your custom inlet shape. It probably wouldn't be worth the expense in the end.
Either a curve, or if straight then a converging nozzle (think of a trumpet's horn, in reverse) works well to reduce flow losses and gradually increase velocity. Actually the best flow can be obtained from a converging-diverging nozzle--the flow path would widen slightly after the tightest point, creating a venturi effect. Most throttle bodies these days are actually a converging-diverging design.
The problem with this is actually building it--unless you have a spare baritone sitting around I don't see where you're going to get the piping from. To have it fabricated nicely, well I can see it very quickly running up over $500, even using something like plastic sheeting would be a few hundred by the time you got it sufficiently sturdy and insulated. And then you have to find a filter for your custom inlet shape. It probably wouldn't be worth the expense in the end.
05-30-2002, 02:58 AM
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You're right about having one custom made, but I wouldn't think it would cost too much more for a manufacturer to make one of these. The opening of the intake would not be shaped like a trumpet since you're going to stick a filter over it anyway. But a 4 or 5 inch pipe that narrows to 2.5 inches with a slighlty larger cone filter would be very possible, and I think it could be done for a feasable price, maybe around the $200 to $250 range. The real question is would it give enough HP to constitute paying a higher price for it. I sure wish I had the ability to make this dream a reality, I really want to know how much of a difference it would make, if any at all.