Some air filter figuring.

[cycleguy55]

I'm pleased to see the 9" x 2.5" and X-Stream combo is good for minimal loss on your 600 HP engine, as that's the combo I'm planning for mine and I'm nowhere close to that power level.

One aspect not covered in the calculator or your comments is that of airflow direction. Clearly an X-Stream top will allow airflow down into the carburetor in addition to the air flowing in through the sides of the 9" element. The 14" x 3" element, OTOH, passes air through the element and it then needs to flow horizontally before making a turn into the carburetor. I did see a post elsewhere that indicated Chevrolet L-88 drop bases are very good (Experience with Edelbrock air filter), but clearly different drop bases could have an affect on power depending upon how they are shaped and how good the airflow is into the carburetor.

None of this probably makes any difference when the engine is running even under a moderate load, but I could see how it might affect an engine running under WOT, particularly if the carburetor has a choke, as the space between the top plate of the 14" x 4" air cleaner and the choke horn could restrict the airflow.

All this is purely theoretical, and I'm curious as to whether anyone has studied or compared the above.

[Detroit Bill]

Originally Posted by cycleguy55

I'm pleased to see the 9" x 2.5" and X-Stream combo is good for minimal loss on your 600 HP engine, as that's the combo I'm planning for mine and I'm nowhere close to that power level.

One aspect not covered in the calculator or your comments is that of airflow direction. Clearly an X-Stream top will allow airflow down into the carburetor in addition to the air flowing in through the sides of the 9" element. The 14" x 3" element, OTOH, passes air through the element and it then needs to flow horizontally before making a turn into the carburetor. I did see a post elsewhere that indicated Chevrolet L-88 drop bases are very good (Experience with Edelbrock air filter), but clearly different drop bases could have an affect on power depending upon how they are shaped and how good the airflow is into the carburetor.

None of this probably makes any difference when the engine is running even under a moderate load, but I could see how it might affect an engine running under WOT, particularly if the carburetor has a choke, as the space between the top plate of the 14" x 4" air cleaner and the choke horn could restrict the airflow.

All this is purely theoretical, and I'm curious as to whether anyone has studied or compared the above.

I saw that post.
There is benefit in theory to the flow coming straight down but who knows.
One of the best air intake scenarios is the velocity stack anything but that the air has to curve and there is turbulence.

As far as I could tell to do a drop base you need a 14" filter and I don't see many photos of a Cobra with a stock hood and a 14" filter. Maybe someone will chime in a point out some examples but I think it is a tough fit on many cars.

[cycleguy55]

Originally Posted by Detroit Bill

I saw that post.
There is benefit in theory to the flow coming straight down but who knows.
One of the best air intake scenarios is the velocity stack anything but that the air has to curve and there is turbulence.

As far as I could tell to do a drop base you need a 14" filter and I don't see many photos of a Cobra with a stock hood and a 14" filter. Maybe someone will chime in a point out some examples but I think it is a tough fit on many cars.

I have a 14" air cleaner with a drop base, but it's sitting in a box as the hood won't close with it on. I'm going to a system similar to the MAXX Air System MAXX Air System [427 289 CSX CCX KMP ACE HT SPF] - $267.40 : Acton Custom Enterprises, Custom Metal for Cobras in hopes the filter will fit up into the hood scoop.

I'm also looking at replacing the 1/2" carburetor spacer with a 5° wedge plate (http://www.summitracing.com/int/part...5030/overview/) to angle my carb and air cleaner down 2°, rather than up 3° as it is now, in hopes that will not only lower the front of the air cleaner but also give better alignment of the air cleaner to the hood scoop.