NC MX5

[The Bogan]

Question for people who "know stuff"

I am looking at doing the new intake like the one in the picture (the pictured is designed for the OEM TB and intake plenum), this design has the filter behind the front bar, but, the filter sits where the OEM duct heads into the front bar, and the standard aperture when the OEM ducting is removed allows the filter to pulled back out of the front bar into the engine bay for servicing, a simple blanking plate is used to seal the aperture behind the filter

This will require a 45° silicone hose from the TB, like the alloy pipe that is currently there, to another 45° silicone hose to get a straight run to the aperture in the front bar

Question: how will it effect the tune if I move the MAF about 100-150mm forward, the red is around where my MAF is currently, and the green would be where it would end up

Like this

This is the hole the filter goes through 

Ends up like this

LOL..Cheers

 

 

[MBS206]

My guesstimate, with no real numbers to back it up, is it won't effect it greatly at all.its not a huge change in position, and I can't see the air flow changing from in turbulence that much based on distance, and what's in front of it.

Johnny and Brad may have some more numbers to share from experience though.

[GTSBoy]

My thought is if you were just moving it forward and the upstream geometry remained the same, then no difference at all.

But because the current one has the filter direct into the AFM inlet, you effectively have the best chance of a completely symmetric air flow profile upstream, and in, the AFM, whilst the aftermarket inlet thingo has a (small, to be sure) bend between the filter and the AFM. That would bias the flow to the outside of the bend (downstream of the bend) which might well reduce the size of the signal seen by the AFM, for the same total flow rate. Having said that:

• If you're proposing to make your inlet look like a hybrid of your existing one and the aftermarket one, such that there is no bend where the filter is clamped on... then I say it will be just fine.
• If there is going to be such a bend, then, if you can align the insertion of the AFM blade such that it is at right angles to the plane of the bend, then there is a better than even chance that the centreline velocity where the blade is will remain more or less the same, and the velocity will just be a little faster to the outside of that, and just a little slower to the inside.

**This is not professional investment advice and you should consult a suitably qualified ouija board, tea leaves or the intestines of a goat for more accurate prognostication.

[The Bogan]

So, went shopping at Just Jap for things that might work for the intake 

After some trial fitting there I ended up with a 3" x 45° silicone bend, a 3" x 300mm alloy straight, and a humped joiner, some minor trimming will be required to shorten some of the stuff, but nothing that is beyond my "ham fisted" skills

The guy at Just Jap was most helpful as we had all sorts of joiners,  bends and stuff out trial fitting 

Laying it out above the stuff in there it seems everything will fit nicely, and looking at it, it is probably the way I should have been looking at doing it from the beginning, probably.....

In the end it is a front bar off job anyway to remove the original stuff behind the front bar that is taking up the required realestate needed, so maybe a Thursday or Friday job

And because I'm a hopeless consumer, I grabbed some new steel wheel nuts, the current ones are a spline drive type with a "security" socket, that somehow someone keeps misplacing, the new ones are a basic black steel 17mm hex socket

In other news: I just did my "final" tax return, I am now officially a old retired veteran pensioner, and I'm milking the system for all it's worth,  life is good

[Kinkstaah]

I mean it's a bit late to say "This won't have any tangible effect and it is not worth spending more than about three seconds on it, please just enjoy the car"

But I said it anyway.

Does the pod actually get any airflow in that position behind a bumper like that?

[Duncan]

Quite right, if you make it to that pension you deserve every cent

[The Bogan]

6 hours ago, Kinkstaah said:

I mean it's a bit late to say "This won't have any tangible effect and it is not worth spending more than about three seconds on it, please just enjoy the car"

But I said it anyway.

Does the pod actually get any airflow in that position behind a bumper like that?

Yeah, plenty of air flow, there is a dedicated path that feeds the air in to the OEM intake tube behind the bumper

As for a "tangible effect", maybe, but getting the pod/intake air out of the hot engine bay is worth it psychologically to me, even if it gives no performance difference, so the tangible effect in my Lizard brain saysss yessss 

In the end, to me a tangible effect isn't always about performance, sometimes it a sound or a look, or even a...... feeling 

Ooga-Chaka Ooga-Ooga

Ooga-Chaka Ooga-Ooga

Ooga-Chaka Ooga-Ooga

Ooga-Chaka Ooga-Ooga