Selene - Nev's NB SE

[speed]

Seriously, we need to catch up, I'd like to see the progress on your little red beastie too....

Have a room full of parts but otherwise no action. My front yard looks like an old VW dealership.

[Nevyn72]

Anyway, where are we up to?
...........
- Actually go for a drive somewhere....... Ummmm...... Working on that one......

A night time club run to Palm Beach and a few hours playing in Royal National Park today so...... CHECK!

Time to start playing with the next project, just waiting on one part to arrive, yes I'm talking to you Australia Post.....

[Nevyn72]

So...... Let's talk about Intakes.

It's fairly common knowledge that the factory intake on the the SE is, if we are being generous, less than ideal.
Most of us wouldn't be that generous......

In fact they did such a good job that there have been no less than seven different aftermarket replacements available on a fairly low production run car, many are still available new even 10 years after production ceased!

So what was so wrong with it?
You can say a picture tells a thousand words so here it is (spread out a little for your viewing pleasure) in all it's convoluted glory.....



Needless to say the little IHI turbo fitted has a fairly hard time trying to suck air through that long, narrow, twisted noodle of an intake path!
It's generally recognised that replacing that debacle with something a little more free flowing is worth in the region of 20 RWHP....... Simples!

So which of the off the shelf solutions am I going for? None of them.....
Why? Because I'm difficult!

Each of the aftermarket options have their own limitations and drawbacks, some are not made anymore, some don't work with RHD vehicles, some feed the hot turbo outlet pipe straight through the cold air box, plus other little quirks and niceties.
Besides where's the fun in just buying (upwards of $500+ in most cases) and bolting on a kit? It's much better (most sane individuals would say painful) to create something from scratch so onwards.... time to reinvent the wheel!...... again.

Seriously though, none of the available kits quite fit my needs and desires and well...... I just don't like any of them that much.

I have a few requirements for what I'm trying to create;
- fully reversible (the factory intake will be removed and put in a box incase I don't like the final result)
- stealth (has to look as OEM as possible)
- relatively quiet (the price paid with all aftermarket options is an increase, sometimes significant, in induction noise)
- Cheap (I don't like waking up the moths in my wallet)

Wish me luck!

[luzinit]

I have exactly the same requirements as you and none of the aftermarket options have ticked all the boxes (none are enclosed other than SMB).

I've had visions of leaving the stock airbox in place, whilst simplifying the plumbing and fitting a pod inside it.

Very keen on what you will be building. Are you doing it yourself or enlisting help from a workshop?

Cheers
Tony

Sent from my SM-G920I using Tapatalk

[Nevyn72]

Are you doing it yourself or enlisting help from a workshop?

Much to learn you have young Padawan...... To truly understand the boost you must embrace it without outside influences..... down that path lies cost.... loss of credibility.... the Dark side......

[Nevyn72]

Been making some good progress today, some things have worked better than expected, some not so well....

I'll post some progress pictures later today.

[Nevyn72]

So this morning I begun my little adventure in crazy custom stealth intake manufacturing!

Here's were we are starting from because, well you have to start somewhere.....



So obviously the first step is to remove all of the old intake system.

The turbo outlet pipe and oil catch can (hiding behind the airbox in this picture) were also removed because they were in the way.

While this resulted in a whole lot of free space, it's actually still quite restricted in there....



Now the next step is to work out what to put back in it's place.

For those who know me, you would realise I've been toying with this concept for a long, long time now. I've come up with any number of different ideas, some of which I've even partially mocked up before throwing them in the bin due to being impractical, unworkable or well.... just plain dumb.

The fundamental problem is you need to make a link between the turbo inlet and the coolish air source located behind the passenger side headlight from the guard. Unfortunately this coolish area is also where the factory hotside turbo outlet pipe runs, hence why a few off the shelf options have this pipe running through the airbox.

Have a look at the image below to to see the locations of the critical areas....



So, how to make something that fits in that space while still looking OEM?
That's the problem that I've been wrestling with over the last year and a bit!

Obviously the most significant OEM component is the airbox so being able to use that will go a long way towards achieving my 'Stealth' goals.
Unfortunately being the same unit as the one used in the Non-turbo NB's it's big, oddly shaped and the MAF outlet faces the radiator. Of course the turbo inlet also faces the radiator. This in combination with the relatively tight clearances when you factor things like AC & Power steering pumps is the whole reason why the factory came up with the noodle they did in the first place.

In my next post I'll take you through my design concept and show you how it's shaping up so far.

[Nevyn72]

Now with what I'm trying to achieve I've put a few design constraints on myself in the process.
- It needs to work with the factory ECU (at least for the moment)
- hence it also needs to work with the factory plumbing -> BOV recirculation, vacuum return from the EBC and vent return from the catch can.
- The MAF also needs to be retained which takes up even more space.

So basically I have to make as short and straight a connection as possible from the forward facing MAF (70mm) to the, also forward facing, turbo inlet (45mm).
I also have to provide for a 5mm and two 20mm openings in this link for the plumbing mentioned above.
While also looking at least sort of OEM, what a headache!

I tried many different concepts including reversing the flow of air through the airbox (no where to put the MAF), hiding the MAF and a pod filter inside the airbox (not enough room), repositioning the airbox to allow a simple U-shaped pipe to the turbo (not enough space, again), even using a completely different airbox (couldn't find one that worked in the space).

Finally late last year I had a brain wave and thought of turning the airbox 90* so the MAF faced the engine. It looked like it would fit (with some very heavy modification) with the MAF reasonably close to the turbo inlet and had the added bonus that the factory rubber elbow attached to the turbo inlet which alters the path to vertical could be retained making going back to stock a LOT easier! It would also make the intake path VERY short, shorter than almost every off the shelf solution out there..... Cool.
So all I needed to do was work out some way of making a 90* bend in a pipe while also reducing the diameter from 70mm to 45mm while also providing the ability to tap a 5mm and two 20mm pipes into said pipe, all in the space of 250mm total length and look OEM in the process..... Yeah, this is going to be fun.

This was late last year and work was ridiculously busy so I knew I wouldn't have the time to do anything about it until my holidays (now, Yeah!).
However while pondering the concept and looking for solutions so I could at least start sourcing the required parts I spotted something in my miscellaneous collection of bits....
Hmmmmm, I wonder if that will fit?

BINGO!



Anybody here recognise what that is? Hard to get something more OEM looking than that!
It will be interesting to see, being rubber, how well it resists collapsing when the turbo is on boost....

Now this would only get me part of the way there in size hence why I bought the metal reducer which I posted about back in December to get me the rest of the way down to the required 45mm.



So that gets me to today.

In the next post, construction begins...... You can see how it's all coming together so far.

[Nevyn72]

Now it's time to start getting really messy!

The first task was to position the base of the airbox as everything else hinged of this and it is the component that requires the most drastic surgery.
I progressively removed more and more material from the base until I thought I had it in roughly the right position and drilled a hole in the plastic base to use an exisiting captive nut in the frame rail to secure it.

It ended up looking like this....



I then added the lid to see how well the MAF lined up with the turbo inlet.

Almost looks like it came from the factory like that!



Unfortunately there was a problem...... The bonnet wouldn't close as the whole lot stood too tall.

So out with the devices of mayhem again and I removed some more material.
Actually a whole lot more material.......

This is what was left by the time I had finished.
I even had to add a metal bracket so I would be able to secure the skeletal remains to the frame rail.



Now, air will enter the airbox via the gaping hole on the right side and the previous oval opening to the mid-left will be sealed.
I will also be fitting a 'wall' that will extend forward towards the headlight when installed to discourage hot air from behind the radiator moving towards the airbox opening.

Unfortunately this will not look OEM at all.
So I've come up with a semi-functional mis-direction that you'll see in the next picture.

The final step for today was to test fit the whole lot and see how well it works.
Here it is!



The elbow from the MAF lines up pretty well with the turbo inlet elbow and both being rubber should allow adequate flex for engine movement.
It does look like running the pipe from the turbo outlet to the front of the car may have some tight clearance issues but hopefully it'll work out....

So that's where I'm up to today, tomorrow I'll start the oh-so-fun job of plastic welding the airbox lower section back into a semi rigid piece, I'm so looking forward to that little job!

[Nevyn72]

I forgot to mention that during the first phase, while everything was out of the way, I popped the heat shield off the exhaust manifold to check the manifold to head nuts.
This is a know weakness and the nuts often back off by themselves resulting in reduced boost, odd noises and frequently a warped manifold.....

Nett result was that 8 nuts were nice and tight, the remaining nut required about 1/8th of a turn to get back to torque specs.
I figure this is a pretty good result given that over in the US they often find multiple nuts spinning freely on their studs!

[luzinit]

Awesome work, can't wait to see the final result and hear your feedback on performance improvement!

[Roadrunner]

Very keen to see how you go with this. You certainly get an A for effort!!

Your not looking at a way to reroute the hot pipe from having to go up and over and then in behind the headlight?

[Nevyn72]

You're not looking at a way to reroute the hot pipe from having to go up and over and then in behind the headlight?

Re-routing the hot pipe is a little beyond the scale of what I'm doing here as it would require some major surgery of the intercooler pipework and I'm not quite sure where exactly I'd route it....
That being said I have though of one possible way but that would require a whole lot of work and a different intake/airbox solution!

Realistically this intake design isn't going to be a top end performer (it still uses the factory air filter), I'm not chasing peak horsepower (so peak flow isn't as critical) and the baffle I've added should mean that apart from the radiant heat from a short section of the hot pipe the airbox should be mostly drawing air from the cool source behind the headlight.

Anyway I might throw together a quick update while I'm waiting for some paint to dry........

[Nevyn72]

The first job for today was to make the third intake connection to the rubber elbow that attaches to the MAF.

This elbow very helpfully already has two fittings, one 20mm and one 5mm, the third opening has a metal 'socket' with a threaded centre hole which the IAT sensor used to screw into.
Now the opening is too small and isn't particularly suited to attaching a 20mm hose to.....

This is what it looks like.



So I removed the fitting and drilled the hole out to 13mm, mainly because this was the largest drill bit I own.
I then found a bit of pipe from my magical collection of miscellaneous mystery bits and cut off a suitable length.
This was placed into the recess and expoxyed to within an inch of it's life with some of the evil bastard brother of JB Weld!..... That sucker ain't going anywhere.

This is how it ended up before a little cleaning.



Now while that was put aside to set for a while it was time to begin plastic welding....... Oh joy.
This didn't however last very long as after only 5 minutes the soldering iron stopped working. Bugger..... Off to Bunnings we go!

Amazingly I managed to leave Bunnings with only two more things than I was planning on actually buying, that must be some kind of record for me.

There were three welding tasks to complete;
- Strengthen the airbox base and plug the old oval opening.
- Shape and attach the baffle to the airbox base that runs forward towards the headlight.
- Trim and shape the snorkel (which doesn't actually do much of anything apart from act as a distraction so it might as well look neat).

After few hours of shaping, cutting, sanding, welding and frequently burning my fingers they were largely done.
Hmmmm, burny, stinky, halucinogenic plastic fumes...... Oooh, a Narwhal.... No sir I don't have any Tim Tams......

I cleaned them up a bit in preparation for a quick coat of Vinyl Dye to give them that factory fresh look.

Here they are awaiting the first coat of black.





So what's next?

Watching paint dry.......

I'll see if I can achieve anything else this afternoon and post later but from here on it's largely assembly with some minor hose cutting and probably at least one nasty surprise!

[Nevyn72]

And Done!

Since my last post I've now finished the install, YEAH!

First off was to start reassembling the top and bottom sections of the airbox with their ancillary fittings.
Then I fitted the bottom half of the airbox for the last time. You can see the baffle extending forward towards the headlight beside the power steering reservoir.



I then inserted the metal reducer into the turbo elbow and clamped it in place.
Once that was done I installed the air filter and fitted the top section of the airbox with MAF elbow installed.

This allowed me to just how close the two ends of the intake were and how much pipe would be required to join them..... It ended up being a little closer than I had intended but still good.



So now I needed some pipe, 55mm in diameter, with a bend.
Luckily the spares box came to rescue again in the form of the old cold side intake pipe. It even came with helpful bends.



I chopped a very small section out of the middle and fitted this between the two sections of intake pipe. Done.

So next was to fit up the rest of the connections and reinstall the oil catch can.

This meant raiding the spares supply yet again to find various clamps and hose lengths, fortunately I had pieces that were suitable, even with bends in the appropriate spots.

It's all coming together very well and looks like this.



Now the sun is starting to go down but I'm oh so close so decide to power on to the end.....

This meant making the connection between the turbo outlet pipe (vertical) and the hotside pipe that runs next to the radiator.

The turbo outlet pipe is 1.5" and the hotside pipe is 1.75".
The factory setup uses a 90* elbow in 1.5" which attaches to a metal pipe with a 0.25" step in it followed by another 90* elbow in 1.75".

Now because I'm preserving the factory setup in case I want to change back and the metal pipe is integrated into the intake piping assembly I couldn't use that section. As a result I bought a replacement elbow for the turbo outlet which not only does a 90* bend but also increases in size from 1.5" to 1.75". This made it much easier to source a section of metal pipe as it only had to be 1.75" straight through. I ordered this pipe with a 15* bend and longer than the factory unit as I was expecting to have to route this pipe further over towards the engine to clear the intake MAF elbow. I was right.....

All I had to do was trim about 25mm off the factory 1.75" 90* elbow that attaches to the hotside pipe and it all lined up surprisingly well.

Here's the final result!





Only one thing to do now...... Take it out for a drive!

Backing out of the garage I was almost a bit disappointed as it seemed no louder than before, I was expecting more, or at least something. I shouldn't have worried.
First off was just some gentle driving to warm the car up and make sure everything was working ok, it wasn't. The coolant gauge wasn't working, I was wondering why it was taking so long to warm up. So I quickly pulled over, jiggled the connection on the sensor and all good. Now the temp gauge was functioning I could see I was already up to operating temperature so off we go!

First thought, the turbo whistle is definitely louder but not significantly, good. The BOV though is another matter....
Previously I rarely, if ever, heard the BOV operate and if I did it was muted and distant, not anymore. Now from relatively low revs it's quite intrusive though surprisingly at higher RPM much less so. The real issue for me is the noise it makes, somewhere between a bird chirping and a small dog sneezing. Given it's so unfamiliar I'll just have to wait and see if I can adjust to it.

Now for power.
Does it have more? - Hell yes!
Is it night and day? - No

However I'm still running factory boost so I can see what effect the intake has by itself. Normally when people replace the intake they also add a manual boost controller and up the boost from 7.5 PSI to ~10 PSI at the same time which increases the impression of more power.

That being said I was initially unimpressed with the power increase, thinking this was no better than before. What I didn't realise was that I hadn't gone over 5000 RPM yet so was inadvertently comparing full 5000 RPM+ power pre-intake with ECU strangled sub 5000 RPM power post intake. Once I made the transition past 5000 RPM my face looked something like this ->

Cool!

So What's the final assessment?

I had a few requirements for what I'm trying to create;
- fully reversible (the factory intake will be removed and put in a box incase I don't like the final result) - Check
- stealth (has to look as OEM as possible) - I think we can definitely say yes to this one.
- relatively quiet (the price paid with all aftermarket options is an increase, sometimes significant, in induction noise) - 50% Will have to wait and see about the BOV noise.
- Cheap (I don't like waking up the moths in my wallet) - Total spend on all parts used was <$100 so yes, I'll claim this one.

I only went for a short dive this evening so will report back after I've the chance to go a little further afield.
Tomorrow? I need to tidy a few small details and clean up the bomb site that is my garage!