Interesting Ram Air

[BryanL]

Wow talk about overcomplicating something that is really quite simple. The best way a racer can "protect themselves" is by not installing something that any reasonable person could construe as being able to provide increased air pressure at the intake. If you believe ram air doesn't actually work, then you have no reason to have anything other than a system that is obviously not capable of creating a ram air effect.

Al-you lost everyone in this group when you said "reasonable person". Seems obvious that even the directors disagree on what constitutes ram air and what should be allowed/not allowed.

There isn't even an answer to whether a 93-97 car with an LS can run the factory LS air filter or if one can run the factory LS filter with an LT.

A director explained to me that unless it's a sealed system grabbing air then it's not a ram air and legal. This would include trimming the bottom of the LS tray which clearly isn't sealed.

[Supercharged111]

Al-you lost everyone in this group when you said "reasonable person". Seems obvious that even the directors disagree on what constitutes ram air and what should be allowed/not allowed.

There isn't even an answer to whether a 93-97 car with an LS can run the factory LS air filter or if one can run the factory LS filter with an LT.

A director explained to me that unless it's a sealed system grabbing air then it's not a ram air and legal. This would include trimming the bottom of the LS tray which clearly isn't sealed.

Bear in mind for something that questionable I would require data to allow it, but if the data supports it then it is what it is. My point is that I don't like the idea that something can be deemed illegal at a glance because one person perceives it is ram air. The way the rule is written allows just that with no opportunity to objectively prove oneself one way or the other. In the case of the hacked up LS airbox, there is still a leak that flows 300whp unrestricted that, as far as I can tell, has no appreciable positive air pressure trying to force it's way in.

This LS airbox may be a bit of a 1 off. I think it's worth validating with actual data and perhaps specifying how many square inches can be removed.

[BryanL]

1. Can we get an answer on the LT cars that have swapped to the LS being able to run the factory original bottom air box?

2. Can we get an answer on the LT cars being able to run the factory original bottom air box?

Those should be an easy yes?

Then we can get into the definition of ram air and whether cutting the plastic is the same as removing the headlight and installing a duct to grab air and direct it at the open air filter. We don't use data for much more important considerations so why would we start with this? Also, I have no clue how to obtain data on my LS1 or a 5.0, 4.6 etc.

[Al Fernandez]

Not sure I understand what "bottom air box" means, but the only stock unmodified air/filter assembly I am aware of that is not legal is the LS SS one, regardless of what body the engine is updated/backdated into.

My definition has always been that if the cross section flow area that lets the air into the "duct" is larger than the cross section area of the TB and any bypasses to the TB then you have the makings for increasing pressure...so don't do that.

[Supercharged111]

Bryan in case I was unclear, having reread the rules it seems they are written in a way that would allow an LS style airbox to be run with an LT1.

6.21.5 Any air filter or air filter assembly may be fitted and OE assemblies may be modified. Air boxes and filters must reside inside the engine compartment or in the OEM stock location. Air filter installations intentionally designed to create, or that appear to create a ram air effect are not allowed, even if they were OEM stock.

I was hung up on OEM stock location, but inside the engine bay is another option.

Al, for those assemblies that appear to create a ram air effect, I think the rules ought to give the driver an opportunity to defend their creation. I like your idea of cross sectional area. I think we could say that, for those assemblies that appear to give a ram air effect, the driver can defend himself with data. It would read something like:

Air filter installations intentionally designed to create, or that appear to create a ram air effect are not allowed, even if they were OEM stock. Manifold air pressure with the intake fitted at speed may not exceed that of an open throttle body. It is the driver's responsibility to provide data upon request to defend a questionable intake. If a driver lacks the means to provide data upon request then the intake must be modified to eliminate the appearance of any ram air effects. All intake modifications must be listed under item 7 of the dyno test data and vehicle specification sheet.

[Al Fernandez]

The rules already provide a driver ample opportunity... CMC rules clearly state the competitor has the burden of proof, see CMC 7.7. Furthermore, the CCR allows any competitor to appeal any decision of any NASA official, see CCR 17.5