Question about fresh air systems on brands other than Mopar

[Ghoste]

Why do Ford and GM prefer to use a system that only comes open at WOT?  Did Chrysler leave it to the owners preference out of being cheap or is there a performance based reasoning behind it?
By that I mean are the other brands calibrated differently for emissions reasons and their engineers didn't want their owners messing it up by having open all the time and thereby necessitating a richer carb setup?
Do the Ford and GM fresh air setups offer much in the airflow department anyway?  Some of the Chrysler ones were pretty marginal too but even something like a 69 Plymouth Air Grabber looks to allow more air in than say a 1970 W30 Olds?

[68 RT]

That is really the only time you need the extra air when you stab it.

[Ghoste]

That part I understand but when you look at the Brand X versions with the trap doors and vacuum canisters and so forth, it seems like a lot of added complexity, and for what?  Just because you only need it at WOT? 

[maxwellwedge]

The Chevelle Cowl Induction was just cool. Same as the Air Grabber. Roger Huntington once proved the effect of a cold air scoop was marginal under 80 miles an hour, He did love the usefullnes of the A12 scoop claiming it made 2 or 3 10ths difference in the 1/4 mile.

[Ghoste]

The cowl induction one I can see having a vacuum operatd trap door because the driver can easily see it coming open under demand.  That plays highly into the gimmick factor so from a marketing standpoint I completely get those ones.

[68charger383]

The 67/68 firebird ram airs were open 100% of the time. (see pic below) It technically can not be operated in the rain/snow etc. for obvious reasons. They didn't come up with a shaker type manuel scoop flap for it until 69.

I think it was just a matter of functionality, race on Sunday drive to get groceries on Monday, so only need the WOT at certain times, Ford/GM had it automatically occur and Chrysler gave the driver the option of when to open it up.

If it was a GM/Ford they were racing, then they wouldn't need the extra 1/10th, but if it was another mopar, they would probably need that little extra push!  

[Ghoste]

Didn't know that about the Firebirds, I thought all the Pontiacs were automatic.

[The70RT]

The 67/68 firebird ram airs were open 100% of the time. It has a caution since it technically can not be operated in the rain/snow etc. They didn't come up with a shaker type scoop cover until 69.

I think it was just a matter of functionality, race on Sunday drive to get groceries on Monday, so only need the WOT at certain times, Ford/GM had it automatically occur and Chrysler gave the driver the option of when to open it up.

If it was a GM/Ford they were racing, then they wouldn't need the extra 1/10th, but if it was another mopar, they would probably need that little extra push!  

Yep and the 442's were open all the time too....except at cold start up. I believe Buick GS's were open all the time as well.

[Ghoste]

If they are only closed at cold start then why all the vacuum hoses running around their setups?  What year 442 are you talking about?  Firebird too for that matter because the 69's definitely have a vacuum hose running up to the scoops.

[The70RT]

If they are only closed at cold start then why all the vacuum hoses running around their setups?  What year 442 are you talking about?  Firebird too for that matter because the 69's definitely have a vacuum hose running up to the scoops.

The air breather is a dual snorkel type and hoses ran under the bumper....may just be the 68 w30 models though.

[Ghoste]

I was thinking of the 70 and up versions.  Interesting that when they used the smaller engine they probably had a better working ram air.  I've often thought about trying to adapt a version of the under bumper setup to my car but it would be a lot easier to stick the 67 Hemi Super Stock style hood scoop on there.

[dstryr]

Tom Hoover spoke about package cars and the A12s at the 2005 All-Chrysler Nationals and had a few comments on the GM tri-powers and cold air intakes.  My recollection(best I can do) was that his opinion was that the tri-power manifold runners were too short to take advantage of the carbs and thus the taller design of the Edelbrock and subsequent Chrysler cast iron 6bbl intakes.  The other thing was that the GM low profile scoops sat below the air stream and were somewhat ineffective at higher speeds in not providing a ram effect but only cool air.  The evaluation of the GMs also led to the taller scoop design on mopars for production cars where the scoop was in the air stream.   I probably left out a detail or 3 but those were his general ideas on the comparison of the GMs and the first Mopar 6bbl offering. 

I wish we had taped that talk!

[Ghoste]

He gave a lecture at the Chrysler Museum one night a few years ago too that I was unable to attend but I would sure love to have heard it.

[Bobs69]

I realize that this is an old thread but..........


I used to have a magazine, and I can't find it, that had all sorts of pictures of the 1969 K&K insurance race car.  I noticed it had a cowl induction.  Nothing sticking out of the hood.  Just a whole in the firewall to grab air from the existing cowl vents, and some special air cleaner.

Has anyone else seen this, noticed or cared?  It sure would force a lot of air down the carb.

[maxwellwedge]

Still pretty standard Na$car stuff to this day.