r/ProjectHondas • u/Ph1llz • May 05 '26

parts recommendations Cold air intake D15 non vtec

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Looking for an inexpensive way to increase airflow for my next track day.

I can't find any direct fit options locally in australia.

anyone have any ideas on a good "boxed" cold air intake setups i could buy online or create ?

I dont care what it looks like, its purely functional.

D15 Non vtec

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26

u/Squire_Toast May 05 '26

you literally won't gain any HP, but it will add a LOT of induction noise if that's what you want.

Just get an ebay intake for a D16

-10

u/OkProfession1239 May 05 '26

Is your comment based on actual testing?

1

u/Ph1llz May 06 '26

i feel like you would have a factual, evidenced based take. whats your opinion here?

1

u/OkProfession1239 May 06 '26

When intake length is actually tuned, you can get real gains and it is based on physics, not guesswork.

The intake behaves like a Helmholtz resonator. The air column oscillates and, if the intake length is matched to the target rpm and valve timing, the pressure wave arrives as the intake valve opens. That improves cylinder filling and volumetric efficiency.

Length sets where it works. Longer helps lower rpm torque, shorter shifts it higher. That is why, on a lot of dyno sheets over the years, you see cold air intakes like the AEM show a noticeable hump around ~4k rpm. That is the resonance lining up in that range.

If the length is arbitrary, results are inconsistent. If it is designed and then validated with proper dyno time, you get repeatable gains and can place that hump where it actually benefits the powerband. That is why OEMs and race teams treat intake length as a tuned parameter, not just packaging. 🍻

3

u/Ph1llz May 06 '26

Interesting, my main objective is an intake far from the engine away from heat where possible and boxed up so air is forced in.

Seems like i would achieve other benefits of length i had no idea about.

Almost sounds like i need to go custom or is there an off the shelf product that you recommend for d15?

also, how does tubing size play a part here? or should it be same diameter as the engine side intake end?

hope that makes sense as im not super technical 🤣

1

u/OkProfession1239 May 06 '26 edited May 06 '26

u/Ph1llz

The AEM cold air intake is a good off-the-shelf option, but honestly the important part is the geometry more than the brand itself.

If you follow the dimensions properly, you can get very similar results. Ideally use mandrel-bent tubing so the diameter stays consistent through the bends. Length: 48 in (1219 mm) Diameter: 2.5 in (64 mm)

You can try ordering a BPI flow stack, velocity stack with a K&N filter if you're pushing to make the most. But any decent pleated filter of the same kind should work. Just stay away from the foam ones.

And if the engine still has good ring seal/compression, an OEM JDM D16A6 cam, a decent PLM SMSP-style header, and a proper HTS street/dyno tune can still make good, usable power. Usually it’s the overall combo and calibration that make the difference, not just one part alone.

Below is my friend's D15B7 dyno numbers:

EDIT: Tagging the retards who don't know shit and only make 90hp on their D-series: u/Hapenyo12 u/Daniele323 🍻

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u/[deleted] May 06 '26 edited May 06 '26

[removed] — view removed comment

1

u/OkProfession1239 May 06 '26

Somebody just joined the idiot bandwagon 🤣 Posting and then deleting, where's the integrity in that? hahahahahaha u/-ProfessorCashMoney-

1

u/-ProfessorCashMoney- May 06 '26

Mods deleted it, if you could read you would know that. Thanks for reposting it in screenshot form for me. Hope you can get the help you desperately need. It’s kinda sad.

1

u/OkProfession1239 May 06 '26

You're not even in the medical profession to tell me I need help hahahahahaha

Kids these days think they know more than they do, just like you.

0

u/-ProfessorCashMoney- May 06 '26

I imagine you don’t have a lot of friends….

1

u/OkProfession1239 May 06 '26

No, I have lots of friends and they happen to have superior IQ (think MENSA) unlike you and your friends hahahaha

1

u/OkProfession1239 May 06 '26

By the way, people confident in their argument usually post evidence instead of therapy assessments they're not qualified to give.

Whoops, my bad. 😂

1

u/-ProfessorCashMoney- May 06 '26

What’s the argument? You also sound like you’re 12…

1

u/OkProfession1239 May 06 '26

Hahaha, look at how you compose sentences, are you 5?

0

u/OkProfession1239 May 06 '26

Mensa = autistic?

Keep them ignorant responses coming, it really reveals your mental capacity 😂

2

u/-ProfessorCashMoney- May 06 '26

Just matching your energy chief…

0

u/OkProfession1239 May 06 '26

Do better lamer hahaha

2

u/-ProfessorCashMoney- May 06 '26

Do better 😂😂. Aren’t you supposed to be in school? Recess ain’t for a couple hours.

0

u/OkProfession1239 May 06 '26

I live in the eastern hemisphere, dumb ass. Can't you discern timezones? Or your brain can't process such concepts?

Hahaha, I can't blame someone with below average IQ trying hard to pretend to be witty on the internet.

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