Custom Intake Tube Questions
#1
Custom Intake Tube Questions
Hello Everyone,
I somehow got the idea that I was going to 3D print an intake tube for my truck that eliminated the silencer and when I started CADing it, I got thinking. Correct me if I'm wrong, I think that the silencer on these intakes operates by using Helmholtz resonance to cancel out the pulses from each valve event. Now if that's correct that would mean a new intake tube without this would only increase noise, and assuming it was made less constricting, flow more.
Using fusion and some photos I took I was able to rough in the shape of the intake tube and found that for about 1/3 the distance of the intake the diameter narrows to the equivalent of a 3.25 inch diameter. Maybe I'm doing my math way wrong but the flow through that meets or is just under that of the engines at 6200 RPM (I calculated 477CFM), so are there any real gains in using something like some highly recommended modular intake tube other than eliminating the silencer? And wouldn't going with something like a 4" intake tube kill the velocity enough to mess with how air travels over the butterfly and richen up the rear cylinders since they lose out on the "ski jump" effect, where due to the velocity of the air and the angle of the butterfly the air "jumps" to the rear ports? I personally would love some more noise out from under the hood, but I don't want to reduce performance either.
I somehow got the idea that I was going to 3D print an intake tube for my truck that eliminated the silencer and when I started CADing it, I got thinking. Correct me if I'm wrong, I think that the silencer on these intakes operates by using Helmholtz resonance to cancel out the pulses from each valve event. Now if that's correct that would mean a new intake tube without this would only increase noise, and assuming it was made less constricting, flow more.
Using fusion and some photos I took I was able to rough in the shape of the intake tube and found that for about 1/3 the distance of the intake the diameter narrows to the equivalent of a 3.25 inch diameter. Maybe I'm doing my math way wrong but the flow through that meets or is just under that of the engines at 6200 RPM (I calculated 477CFM), so are there any real gains in using something like some highly recommended modular intake tube other than eliminating the silencer? And wouldn't going with something like a 4" intake tube kill the velocity enough to mess with how air travels over the butterfly and richen up the rear cylinders since they lose out on the "ski jump" effect, where due to the velocity of the air and the angle of the butterfly the air "jumps" to the rear ports? I personally would love some more noise out from under the hood, but I don't want to reduce performance either.
#2
TECH Senior Member
Don't overthink it. Provide an unimpeded 4" path from filter to throttle body or MAF tube. Done.
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Old Geezer (01-08-2020)
#3
I figured I was over complicating it lol, 4" intake tube it is. If anyone is interested I'll post up the finished CAD file.
Just to satisfy my curiosity though, how does one optimize an intake tube to flow the needed amount without any negative effects?
Just to satisfy my curiosity though, how does one optimize an intake tube to flow the needed amount without any negative effects?
#4
#5
TECH Senior Member
Size it to the smallest choke point in the system. Go bigger, but not smaller. A 102mm TB is right at 4" .
A MAF might be smaller, but 4" will take care of it.
A MAF might be smaller, but 4" will take care of it.
#6
I've got 3.5" on the MAF and the stock 78mm TB, total length of just under 21". Planning on using the stock coupler for the TB but getting rid of the corrugated tube from the MAF to the start of the tube and use a 3.5" coupler. The MAF is still currently directly coupled to the factory airbox. So I can't do anything about before the MAF but I can definently do a 6" transition after. Thanks all.
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G Atsma (08-21-2020)