"The Confines of the Engine Compartment"

[Ralf]

Wouldn't that air intake be considered ram air and therefore not be allowed? "Velocity stacks, ram air or cowl induction are not permitted unless fitted as original equipment."

[Greg Amy]

Wouldn't that air intake be considered ram air and therefore not be allowed? "Velocity stacks, ram air or cowl induction are not permitted unless fitted as original equipment."

I don't think so. In my mind it's clearly not velocity stacks; doesn't meet the definition of cowl induction (nowhere near the cowl); and ram air IMO requires facing the perpendicular flow of oncoming air.

One can argue that there is increased air pressure being created in front of the radiator due to forward motion, and this intake system takes advantage of that. I disagree; I suggest that since that area in front of the rad is way wide open with numerous holes all around, any pressure increase is minimal, if at all (and would be tough to prove regardless). Lack of significant increased air pressure negates the idea that it's ram air.

Good thought, though.

GA

[chuck baader]

I have always considered the engine compartment as a place where the engine resides. Clearly, the engine does not reside in front of the radiator, therefore, the engine compartment ends with the rear of the radiator. Non compliant.

[Andy Bettencourt]

I have never considered that intake to be legal for an ITA Miata. I believe, like RP, that anything flush or encroaching on the plane of the radiator sources from 'outside' the bay. That's oversimplified for sure.

[lawtonglenn]

I have never considered that intake to be legal for an ITA Miata. I believe, like RP, that anything flush or encroaching on the plane of the radiator sources from 'outside' the bay. That's oversimplified for sure.

I have always considered the engine compartment as a place where the engine resides. Clearly, the engine does not reside in front of the radiator, therefore, the engine compartment ends with the rear of the radiator. Non compliant.

+1

[Greg Amy]

I tend to agree with the above. However, re-read my post from above and tell me what you think...we're talking only an inch difference here...

Fair enough. So look at that photo of the item installed again. Note that the piece that extends well past forward of the radiator is the mounting system, and there's no limits to the mounting system for the air intake, only limits to where the air is sourced. If he were to trim back the top of that item, where the initial opening of the air source is, to a point right at the vertical plane of the aft edge of the radiator, would that not satisfy the letter (and potentially the intent) of the reg?

[gran racing]

The advice I'd give to that person is that it's quite debatable whether that intake is legal or not. They should also further look into whether there are truly any gains to be made. Then based upon those pieces of information, decide whether or not the hassle is going to be worth it. I looked into it after seeing that intake at Summit Point on the way back from picking up my Miata. I then spoke with ISC and a few other companies. I don't think that is a better option. I do know that every time I raised my hood in impound (do often regardless of whether or not required to), it would cause questions. Then questions about what else might I be doing too. It's also an easy protest that I have to imagine would come with a small protest bond fee. Curious, what do you think that would be?

After this simple protest is filed, it's then going to be a debate amount the powers that be just as being done here. Maybe found illegal then move on up to National.

Back to the real question, it sure looks debatable and right on the edge of the rules if it's not illegal.

That plastic cover near the rad. All year 1.8s have them? I don't recall ever seeing one on a Miata. I'll admit you made me go outside and take a look at mine. It's not there. For cooling purposes, I'd almost think it would be better to have it. My intake is not in that area and don't think there's any impact.