Proper cold air intake for a reasonable price

[Seb]

Hey guys, I want to show the intake I came up over the course of the winter. I didn't want to post before I'm sure of my findings and before the thing is properly tested in real world. As you might know, 2GR is infamous for it's pickyness when it comes to the intake, but there are a few proven aftermarket offerings, like BOE.
BUT - I believe 600+ USD for an intake is way too much. I started researching and a bunch of people already tried making their intakes, found info about Radium intakes and their CEL problems etc. I got discouraged, but given intake's relative simplicity, I got digging - what could be BOEs secret? They don't require any remapping! Then I found a post by Wilhelm Raceworks describing their findings, studied how BOE intake looks and that's where I got my aha! moment.

The catch is in the spike of high velocity air that the stock ECU maps are tuned for, and MAF sensor must be in a location that closely matches OEM implementation. I got measuring, and found it should only be about 6-7cm away from the start of the intake tube, for it to land within that high velocity airstream. So, an enclosed airbox is needed, there's not enough wire in the harness to get a conical filter anywhere in the cold air stream and retaining such a position. This is something that BOE does with their ITG airbox. I knew I needed something like this, so searching again I found Ramair's ProMax PML-76-FR-102

That's one part solved, now we need the MAF tube, courtesy of the leading online performance website and some piping to connect it all - a 76-80mm silicone tube . I decided to see what to do with the big end of the pipe when I get the filter mounted, I guessed it could work and I got lucky, that I could reuse the stock large diameter pipe. After some trial and error, the end result looks like this:

 

I also found out that I forgot the PCV, so with the help of my friend, found about thru-hull fittings, so I purchased one of appropriate dimensions from the everyone's favourite online auction site and fitted it into the approximate factory position, right before the throttle body.

I then made a small bracket to 'hang' it from the engine cover bar, and mounted it for good. I didn't take any good pictures in the process, but here's some after about 2000km of testing, where I can confirm the car performs really well, there's no CELs as predicted, and the sound after 5000rpm is just intoxicating.

 

Here's a final calculation:
- silicon hose 30€
- thru-hull fitting 7€
- ramair filter 175€
- maf pipe 25€
- for free, laying around in the garage: some black spray paint to make the MAF tube more stealth and a new 100mm hose clamp for the intake to throttle body connection

With all shipping etc, I think I'm still below 250€ mark, so significantly less than half the price of BOE.

Let me know what you think!

Edited April 15 by Seb

[Lukeyboy2k]

Really interesting - thanks for taking the time to share. I was just thinking about this last week. Don't suppose you have any video of it in action?

[Seb]

here's a short video I made the other day, but this is only in lower revs (cruising with one hand) 

 

I need to make one where I go over 5k RPM, and the sound really gets crazy at about 6500-7200

[Arregueti]

Hi Seb,

Nice effort. Thanks for sharing. Is your car N/A or an S (compressed)?

[Cdm2018]

Dam ! 
I would have saved myself £400 😱

[Seb]

1 hour ago, Arregueti said:

Hi Seb,

Nice effort. Thanks for sharing. Is your car N/A or an S (compressed)?

It's an NA car. S should be pretty similar, most likely only the elbow needs to be cut at a differnent length to account for the different position of the throttle body

[Lukeyboy2k]

2 hours ago, Seb said:

here's a short video I made the other day, but this is only in lower revs (cruising with one hand) 

 

I need to make one where I go over 5k RPM, and the sound really gets crazy at about 6500-7200

Sounds great, and that road looks brilliant fun. As an aside, what exhaust setup do you have?

[DH2]

Hard to tell from photo, but MAF pointing upwards is suboptimal, as moisture can collect in it.

Looks like you have you deleted the thru fitting?

Have you checked the LTFT?

 

[Seb]

it's actually not poining upwards but rather it's on it's side, so parallel with the ground / engine cover bar. This is the only position that is possible with the stock wiring harness without extension.

thru-fitting is hidden on the inner side, the "patch" is ramair's included sticker, that I plan on putting lotus white letters logo on, to have it look nice

[Seb]

21 hours ago, Lukeyboy2k said:

Sounds great, and that road looks brilliant fun. As an aside, what exhaust setup do you have?

Thanks! I have some better routes that are also wider, but this one is right next to my house. I'll have to rig up something and record the proper sound with more enthusiastic driving.

My exhaust is quite unique, it's a development piece by Blackforest Lotus (formerly Bernd Feistle Sportwagen) in Germany which had the car in possession/service while it was still a Lotus Press Car. They were intending to sell exhausts but I guess it turned out economically unfeasable. It's a valved setup with quite exotic (but not loud) sound even when closed, and when opened it's basically straight pipe.