Air Induction- The Real Scoop

[Keith Seymore]

Originally Posted by Keith Seymore

Here's the car PMD/Royal developed the tripower "Ram Air" system on.

This air pan was made in the Pontiac Engineering experimental metal shop. We got it from Dick Jesse.

K

The astute observer might notice some differences between Dad's car and a regular production version.

On our car the hood bracing was cut before the inner and outer panels were joined together. Production cars retain the inner in that area, either blocking the airflow or requiring the owner to make a similar modification.

Also - our hood opening is trimmed to the maximum amount, making it a little tricky to reinstall the nose piece (aka "hood ornament"). We never ran an open ram air nose piece but ran no nose piece at all, for maximum opening and maximum flow.

These mods were worth about .2 sec reduction in ET, going from 12.40's to 12.20's in back to back testing.

K

[drdave69]

I am in agreement with others that the Firebird Formula is the best looking 'ram air' hood whether it was functional or not.

[Too Many Projects]

Originally Posted by Mr70

Was originally marketed by Chevrolet as their "Power Bulge" hood on the 1970 Chevelle.
Mine..

Hmmm... I had always heard the non-induction hood referred to as the Bulge hood. My '70 had the, standard, bulge hood and I removed the block off plate. It didn't have the seal or direct ducting of the cowl hood, but allowed the ram effect under the hood all the time. The PO had a cowl cleaner on it, with the open top, so it took advantage of that air flow.

[dustinm]

Originally Posted by Keith Seymore

What? It's not supposed to...

(lol)

Seriously, though, since it was sized for the diesel (which flows max air flow all the time) all of the other engines reap the benefit of the additional flow capacity.

Me and the exhaust guys (note: one induction engineer, two exhaust engineers) were always trading off who was going to be the choke point in the system. I recall it ended up being them.



K

Keith since you more than likely have the best hands on experience, what are your thoughts of the aftermarket cold air intakes? Do they provide cooler air? Some I see are just taking in engine compartment air...

[Keith Seymore]

Originally Posted by dustinm

Keith since you more than likely have the best hands on experience, what are your thoughts of the aftermarket cold air intakes? Do they provide cooler air? Some I see are just taking in engine compartment air...

Nope. Shouldn't be any gains in inlet air temperature (since I'm pulling the air from outside of the fender inner; they are often underhood air) or restriction (we've already said the system was designed to overachieve on anything smaller than the diesel).

K

[Too Many Projects]

Originally Posted by Keith Seymore

Nope. Shouldn't be any gains in inlet air temperature (since I'm pulling the air from outside of the fender inner; they are often underhood air) or restriction (we've already said the system was designed to overachieve on anything smaller than the diesel).

K

I was going to say that, but let you speak first, in case I was wrong, again. Both my 2000 and 2011 pull fresh, ambient temp air, from outside the inner wheel house structure.
Many "cold air" aftermarket systems for cars seems to still be under hood, with some getting that air thru the grille.

[Tenney]

More Royal ram air stuff ...

Have been told the first pic with the three hoses running from airbox to firewall (exposure blown-out a bit) is the Car and Driver car. It does have under-hood light, but no specific telltale details.

Though the three holes on firewall shown in a later article correspond w/that concept.

The car, as it came to me, had big car air cleaner cowl-plenum set up, and the holes had been hacked away.

[Keith Seymore]

Look at that Sun Tach sending unit on the LH fender.

I feel like I am meeting a distant relative for the first time or something.

K

[L_e_e]

Here's my attempt at a cowl plenum ram air system on my 74 Z28, using a early 90's GMC HD truck air cleaner and a repo open element base, I lucked out that the factory chrome Z28 lid fit perfectly on to the truck air cleaner. At the same time I also installed a cross ram base with a single 4bbl so I don't know if there were any gains in performance from the cowl plenum but it sure sounded good and looked almost OEM cool which was my initial intent.

[dustinm]

Lee that looks very nice, and factory appearing