GT_NFR

Are you suppose to remove the OEM radiator plate or not? I've read several threads that claim better butt dyno results at speed with the plate removed but folks such as Saki GT and Bob A (SD) are claiming that removing the stock piece is actually detrimental to the airflow through the radiator. Based on the article found in this thread ( https://www.s2ki.com/forums/index.php?showtopic=486270 ), Bob A seems to be saying that the stock radiator plate will help increase the pressure in front of the radiator but shouldn't the AUT plate do the same, or even better?

Dolebludger says you should remove the oem plate:
https://www.s2ki.com/forums/index.php?showt...5&#entry9890367

Saki GT a and Bob A seems to disagree:
https://www.s2ki.com/forums/index.ph...c=308430&st=25

Great article on Airflow:
http://www.msprotege.com/forum/showthread.php?t=100489

Whats the consensus? or is this still a debate?

GT_NFR

no owners have any further input?

Edit: I just realized I mistakenly placed this in the under the hood section, can any Mods move this to the Aftermarket forum? I think that will be more appropriate.

NFRs2000NYC

I have it, and removed the OEM plate. Even if you don't need to fitment wise, why the hell would you want two pieces doing one job? Extra weight? Just take it off.

GT_NFR

^^ They don't do the same job, the AUT plate acts as a scoop, just like the scoop built into the hood, except its smaller. The OEM piece on the other hand seems to be there to create a high pressure zone in front of the radiator.

Saki GT

Leave the OEM in - it serves a different function. After living with one, the AUT mainly plate is for looks imo - it looks nice and keeps the engine bay clean to a certain extent, and may help keep hot air from coming over the engine and into the intake, but I think at speed there's a strong flow up and over the engine, so I'd say it helps create high pressure in front of the intake, but that's about it.

Its great for looks though.

GT_NFR

Hmm, I still don't exactly understand how they are different....I know that Saki_GT and Bob A say they are different but I don't see why.

nearwater4me

It definitely is.

Dan

Saki GT

Think of it like this - the OEM plate was designed and tested by Honda. Obviously, enough air gets to the intake horn, or Honda would have made bigger intakes. The OEM plate keep positve pressure in front of the radiator, helping it push through and into the engine for better cooling (supposedly - no one has mentioned any overheating issues by removing the OEM plate). The net is, keeping the OEM in and adding the AUT plate has no logical connection to any loss in power or hinderance in air pressure.

When you add an AUT plate, it goes over the intake horn and seals the front opening from the top of the engine bay. Theoreticlly, this is causing the air that would flow into the intake and over the engine to all be rammed into the intake horn (or through the hole where the hood latch is). By increasing the positive pressure in front of the intake horn, the relative pressure in the air box is lower, so air will be sucked in with greater force. The net result is more of a ram effect to the intake at speed - more air, denser, better.

In my experience, the cooling plate doesn't make any appreciable difference in performance, but it looks nice and keeps crap from dirtying up the hood, so I like it.

GT_NFR

Here is my theory on the OEM plate.

Disclaimer: I'm not aerospace so I'm going on some basic knowledge of laminar and turbulent flow.

With the OEM plate, you'll notice that is is curved upward and I believe that this is so that it will guide air throughout the entire radiator. As you can see, the OEM plate allows for the air to travel upwards. This can be compared to the outline of a car vs a u-haul. The amount of turbulent air behind a car is smaller than that of a uhual's, the air is guided downwards along a car's contour. The airflow on a uhaul is abruptly disrupted at the end of the U-haul and creates a large vacuum just like when the OEM plate is removed.

My conclusion is that removing the OEM plate not only disrupts the upward airflow to the top portion of the radiator but also decreases pressure above the opening by creating a vacuum effect.

Air travels upward along the OEM plate:


Air is disrupted as there is nothing to guide it after it enters the bumper area:


Car vs Truck




Sorry for the shitty drawings but its getting late and I'm going to get the verdict on my theory from a co-worker..perks of working at an aerospace company .

UPDATE: I have checked with our Aero expert and he says the OEM plate would indeed help with the airflow by delaying the separation of air after it enters the bumper. Without the plate, the air would enter, the top portion would separate and create a wake effect that actually INCREASES the pressure in the area where the wake is present HOWEVER, this is NOT a desirable pressure increase since there will be no airflow to the top portion of the radiator. This wake also creates pressure induced drag...how negligent this drag is I don't know. But, I can say with almost absolute certainty that removing the OEM plate is actually LESS EFFICIENT than keeping it there. Keep the plate folks.

SlidinS2k

I kept the OEM plate in place and cut a rectangle piece out under the induction area of the AUT plate.