"The Confines of the Engine Compartment"

[Greg Amy]

I think I may have accidentally discovered where the item is moot, regardless of compliance.

Look again at that photo of the stock 1.8L Miata. Note that there's a plastic cover over the area on top of the nose, in front of the radiator. This Jackson Racing part pulls air from that area when that cover is removed, and I cannot think of any way where removing that panel is compliant to the regs. Therefore, even if that intake is compliant, I don't think it's nearly as effective unless another non-compliant mod is also done, negating the whole point.

The 1.6L Miata seems to be open there, so may be useful for that car.

Agree/disagree?

GA

[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?