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Old 09-11-2019, 03:30 PM   #1
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Default What is the best intake system length and DIA for 86x86 set ups

What is the correct length to a intake pipe or piping system for the K20A, K20A2, K20Z1, K20Z3 86X86 engines, the 2.0L ?] Might sound like a general question because there are so many intakes on the market for this engine. I will start with my set up and give participation.

I have a 2002 DC5-S K20A2 PRB cams, intake manifold, 62mm TB and stock header cat and exhaust. Engine has 157,000 miles. I have two intakes. A AEM 3" CAI model. I am not using it. I am using the oem black intake hose with a custom transition piece and a K-Tuned 3.5" velocity stack filter combo. A DIY SRI. The bottom of the air box makes a great heat shield to add. Sounds amazing and similiar to a turbo spoiling. I can hear it with no exhaust.

I need to do the exhaust I know. It is just cool to play with the intake before making alot of changes. As this goes along I am going to make a few different lengths of these simple SRI's.

I came about using the oem black intake tube and trying for shits how a K-Tuned 3.5" velocity stack fit inside the tube. I didn't know it would end up so well. However a lip existed on the rubber intake hose at the 3.5" line up. So I made a custom piece which added 3" to the intake system. Getting rid of the lip and smoothing out the transition. I will have to measure the length of the intake tube.

A 3.5" X 3.18" transition was created. I must say it smoothed the low end out big time and enterance into VTC. VTEC just got better. I always felt the typical aftermarket CAI system tubing length was too long. When I had a K20a2 with stg.2 cams and a SC K24 and felt a SRI was best. I want to play around with the lengths & DIA intakes. Ram Air mechanical intakes rather.
I Have a ported RBC , Z1 cams, and a 65mmTB to test with. So this should be fun keeping up with this post.

*** the Blue marker on the fit up pic is on the velocity stack so it looks like I left out huge areas to still remove

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Last edited by Argonfree2; 09-16-2019 at 10:02 AM..
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