1.5T Has anyone noticed the hood's air guide doesn't line up with the OEM intake?

[Nitori]

I was installing my intercooler the other day and I decided to have a peek at how that flap on the underside of the hood seals up against the stock 1.5's intake "ram" ...

Imagine my surprise when I saw this:

It basically blocks a good 3/4 of the intake...
So those 6 slots in the radiator shroud allow air to come up over the top and then the air immediately gets deflected away from the intake.

I wouldn't be surprised one bit if there were pretty significant power gains to be had by adding some system closer to the FK8 that guides air in properly.

Has anyone modded their stock airbox for better air ducting?

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[silverblip]

 

[86salmon]

Couple threads to check out

https://www.civicx.com/threads/cheap-short-ram-plus-uk-gundo-exhaust-mod.23132/page-4

https://www.civicx.com/threads/iat-correlation.36935/

https://www.civicx.com/threads/airflow-mods-cooling-plate-using-short-ram-intake.35918/

https://www.civicx.com/threads/track-day-aero-mod-diy-cooling-plate.36891/

https://www.civicx.com/threads/stock-airbox-modified-for-cold-air.23420/

 

[Nitori]

Couple threads to check out

https://www.civicx.com/threads/cheap-short-ram-plus-uk-gundo-exhaust-mod.23132/page-4

https://www.civicx.com/threads/iat-correlation.36935/

https://www.civicx.com/threads/airflow-mods-cooling-plate-using-short-ram-intake.35918/

https://www.civicx.com/threads/track-day-aero-mod-diy-cooling-plate.36891/

https://www.civicx.com/threads/stock-airbox-modified-for-cold-air.23420/

Good reads! Aerodynamics is a dark art on the outside of a car, inside an engine bay it's straight up witchcraft.

It's an interesting point that the 2.0L has a completely sealed intake tract. The hood has a U shaped seal that sits over the 6 vents and seals to the opening of the factory box.

You can even see the shadow of the seal being slightly cleaner from all the non-stagnated air flowing in there.

SO, that makes me think that the six slots are intended for the 2.0L and just a hold over on the 1.5, which is why there's that flap on the hood basically blocking them off. It sounds silly but something like having 1 part number for radiator plates instead of two represents a whole lot of money saved for Honda.

There's no good way to adapt the 2.0 intake box to the 1.5 intake, but that scoop on top of the 1.5 airbox is soft rubber and easily removable. I wonder if there is some way to make a better scoop that would just pop onto the stock box...

 

[Myx]

Why not just cut enough of the rubber flap off to not block the stock intake opening?

 

[kalvin126]

I don’t think air actually comes in through the front of the hood that way anyways. It is lined with a gasket.

 

[Myx]

I don’t think air actually comes in through the front of the hood that way anyways. It is lined with a gasket.

But it's a guide from what the poster stated. And if it's a guide, it appears it is guiding air. And if it's guiding air, it's guiding it pass the intake opening. Why not use the air it is guiding to guide it into the intake opening?

I know I maybe over simplifying this but that's just my approach to these things.

 

[mvela]

I noticed this on mine to. The first oil change I did on my 2.0 is when I noticed it wasn’t the same as my 1.5t. The 2.0 has almost what I would consider like a factory cold air intake, while the 1.5t seems to just suck air out of the hot engine bay. I know the 1.5t has an intercooler but I still think it should be getting air from a cooler place. I mean just take a look at this picture of the 1.5t in the accord. It has a scoop right in front some slots where the cool air goes right into the air intake. Why couldn’t they have done this for the civic? Zoom in and you can see it has slots right in front of the scoop

 

[kalvin126]

I think this is a fair observation. I wonder what the engineers had in mind for this. I’d also bring up that hondata did their comparisons for various intakes vs stock and they found that stock worked better than most. Even some CAIs

 

[Myx]

I think this is a fair observation. I wonder what the engineers had in mind for this. I’d also bring up that hondata did their comparisons for various intakes vs stock and they found that stock worked better than most. Even some CAIs

I've tested my stock intake against PRL SRI and CAI and a homemade intake (Myxal) multiple times at the dragstrip, on different dates, changing the intake at the track between runs. I can tell you that the PRL and my homemade intake are both considerably better than the stock intake.

The video Hondata did testing CAI vs SRI vs stock stated that the CAIs were the best followed by the SRIs with the stock intake very very close. Go to point 4:15 in the video to see/hear the results. Are you referring to another video Hondata did with intake comparisons?

 

[Nitori]

I've tested my stock intake against PRL SRI and CAI and a homemade intake (Myxal) multiple times at the dragstrip, on different dates, changing the intake at the track between runs. I can tell you that the PRL and my homemade intake are both considerably better than the stock intake.

The video Hondata did testing CAI vs SRI vs stock stated that the CAIs were the best followed by the SRIs with the stock intake very very close. Go to point 4:15 in the video to see/hear the results. Are you referring to another video Hondata did with intake comparisons?

I think @kalvin126 is confused with the Type R intakes where it was found that the stock beats any aftermarket on both low and high end power:

With that said though, the CTR has a completely different intake setup than the 1.5 or the 2.0 NA, even the hood's shape is slightly different and there is a scoop that goes under the standard radiator panel the "base" models have.
I think it's a great example showing that stock airboxes are much better than they once were, and slapping a cone filter on the end isn't the be all end all solution it used to be, unless you are going for max power past about 5000 RPM. And sometimes even then you will still lose to the OEM.

At first I thought that the 1.5's intake trickery was just a parts interchangeability thing to make it compatible with the CRV chassis and engines but they don't share any part numbers, and the fact that the Accord 1.5 has it done right kinda boggles me.

Almost seems like it might have been kneecapped/ignored to keep the Si/Sport models from being too snappy and hurting the sales potential of the CTR...

At this point I'm convinced that the stock box has the potential to be quite good, way better than a lot of aftermarket options even, so long as it gets to the right source of ambient air. (as long as you aren't looking for hella sick whooshes and tsutsutsu noises )

Reminds me a lot of NA Miatas where the dyno proven best "intake" was the stock airbox with the stock snout rerouted to cooler air, which was easiest to get from the cowl where the wiper motor is:

We're talking PVC pipes and a hole saw outshone pretty much anything on the market. You get the air from the right spot, you're in business.

 

[PowerPerLiter]

That rubber air guide squishes when hood is closed slightly and the leading edge appears to go nearly inside the air box snout, albeit just so. Couple options for reasoning to go over....noise reduction.....water ingestion....higher velocity air being DIRECTLY placed into the snorkel....more air directed specifically at the maf sensor. Only things I could even dream up as to why they possibly did it this way. None of which are probably right.

 

[Hondanickx]

The 7Mod tuners did several dynotest on the FK8 where they removed the front lip on the air guide and they claimed an increase of 2-3psi of turbo pressure.
So i think a similar mod would also work good on the 1.5T

 

[Myx]

The 7Mod tuners did several dynotest on the FK8 where they removed the front lip on the air guide and they claimed an increase of 2-3psi of turbo pressure.
So i think a similar mod would also work good on the 1.5T

Where? Been looking around and cant seem to find this specific info. That's a LOT of pressure drop caused by the air guide alone.

 

[Hondanickx]

I heard it from a German fk8 owner ,i 've been searching for the dyno results myself.Haven't Found it yet.
I also Find that a lot increase in pressure.

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