Hey guys so im new here but am thinking about putting a bnr s4 on my speed 6 this spring... I am a little cautious about relocating my ecu stuff and thought about making a custom 3.5” intake.. It would save me money (I work in a weld shop)
and could save me time if I was to clear the ecu without moving it right? Anyone ever tried this?
******** UPDATE WITH HOW TO *********
Ok so I created this thread in hopes of making my own air intake to save money and know it was made by me and not someone else. I want to give others the reassurance that it isn't very difficult and will cut your 3.5" - 4" air intake cost in half!
To start you will want some solid aluminum piping material. I went with some 6061 which welds nicely and is of high quality. I purchased a 2ft long 90 degree piece that was 3.5" diameter and a weld on MAF flange made for 3.5" pipe.
MRP performance seems to make very very nice quality weld on MAF flanges and that is who I chose for that. Then I cut the pipe at an angle best suited to aim the intake from the turbo outward from the block. I had no special tools for this but just simply tried to go for what I felt like was a cut to make one half have a 60* bend and the other half have a 30* bend. I used a little band saw I have and it ripped right through it but barely fit lol
(After having it mocked up it would be better to cut it at a sharper angle or make sure your 60 is 60 degrees as mine seemed shy and isn't quite as angled as I would like)
A belt sander would be my preferred method to make the cut nice and flat afterwards but I had to use a flap disc on a 4.5" grinder and use the ol' eyeball method haha After that I checked with a mazda homie on how far his MAF sensor was from the end of his intake and he said about 4" and has had no issue and doesn't have an air straightener, so I went with that or more. I pre-drilled a pilot hole for my hole saw and cut a hole that was the same inside diameter as the maf flange hole. The hole size should be one and a quarter inches so 1.25".
https://performancemrp.com/images/F198642096
I cleaned up the burs that were around the inside with a inverted dremel bit on my drill since my pneumatic dremel is annoyingly loud. Once I had the pipe cut and the maf placement found and cut I mocked it up on the car how I wanted it all positioned. I will say I actually checked the MAF placement before cutting the hole for it on the car because I wanted my maf to be unseen and on the bottom of the air intake. After finding the correct orientation for it all I taped it all together and marked it with a sharpie across the joint onto each piece of pipe in case it came untaped.
I had to take off the stock bulky plastic piece on my wiring harness as it was kind of in the way for how I wanted the intake to be placed.
I rewrapped the wires in very good quality electrical tape nice and tight and with a double layer. I will also add here that I have an EGR delete and relocated my battery about a year ago to make sure that this would fit nicely without any hassle.
I found a friend in my union local to weld it up luckily but had a couple estimates to have it welded (before it was made to where they could look at it and really get an idea) and they said anywhere from $100-$150 (based on $100/hr shop time). All in all it turned out great and has had zero issues since the install and did not need an air straightener.
Good luck guys and hope this helps someone!!!
and could save me time if I was to clear the ecu without moving it right? Anyone ever tried this?
******** UPDATE WITH HOW TO *********
Ok so I created this thread in hopes of making my own air intake to save money and know it was made by me and not someone else. I want to give others the reassurance that it isn't very difficult and will cut your 3.5" - 4" air intake cost in half!
To start you will want some solid aluminum piping material. I went with some 6061 which welds nicely and is of high quality. I purchased a 2ft long 90 degree piece that was 3.5" diameter and a weld on MAF flange made for 3.5" pipe.
MRP performance seems to make very very nice quality weld on MAF flanges and that is who I chose for that. Then I cut the pipe at an angle best suited to aim the intake from the turbo outward from the block. I had no special tools for this but just simply tried to go for what I felt like was a cut to make one half have a 60* bend and the other half have a 30* bend. I used a little band saw I have and it ripped right through it but barely fit lol
(After having it mocked up it would be better to cut it at a sharper angle or make sure your 60 is 60 degrees as mine seemed shy and isn't quite as angled as I would like)
A belt sander would be my preferred method to make the cut nice and flat afterwards but I had to use a flap disc on a 4.5" grinder and use the ol' eyeball method haha After that I checked with a mazda homie on how far his MAF sensor was from the end of his intake and he said about 4" and has had no issue and doesn't have an air straightener, so I went with that or more. I pre-drilled a pilot hole for my hole saw and cut a hole that was the same inside diameter as the maf flange hole. The hole size should be one and a quarter inches so 1.25".
https://performancemrp.com/images/F198642096
I cleaned up the burs that were around the inside with a inverted dremel bit on my drill since my pneumatic dremel is annoyingly loud. Once I had the pipe cut and the maf placement found and cut I mocked it up on the car how I wanted it all positioned. I will say I actually checked the MAF placement before cutting the hole for it on the car because I wanted my maf to be unseen and on the bottom of the air intake. After finding the correct orientation for it all I taped it all together and marked it with a sharpie across the joint onto each piece of pipe in case it came untaped.
I had to take off the stock bulky plastic piece on my wiring harness as it was kind of in the way for how I wanted the intake to be placed.
I rewrapped the wires in very good quality electrical tape nice and tight and with a double layer. I will also add here that I have an EGR delete and relocated my battery about a year ago to make sure that this would fit nicely without any hassle.
I found a friend in my union local to weld it up luckily but had a couple estimates to have it welded (before it was made to where they could look at it and really get an idea) and they said anywhere from $100-$150 (based on $100/hr shop time). All in all it turned out great and has had zero issues since the install and did not need an air straightener.
Good luck guys and hope this helps someone!!!
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