Air Filter Issues
Thread Starter
4th Gear
Joined: Nov 2005
Posts: 4
Likes: 0
From: Sacramento California
Air Filter Issues
I have a 1968 327 that has been rebuilt with a high rise intake. The hood closes, but the filter case rubes the inside of the hood. I'm currently using a 3" high filter. I tried a 2 1/4" that fit great, but the car lost it's performance.
What I'm thinking is trying a 2 1/4" high filter with K&N's top filter instead of the chrome cover. Does anyone have any experience with this type of filter and would it be able to pull as much air as the 3?
Please let me know, thanks!
What I'm thinking is trying a 2 1/4" high filter with K&N's top filter instead of the chrome cover. Does anyone have any experience with this type of filter and would it be able to pull as much air as the 3?
Please let me know, thanks!
Melting Slicks
Joined: Aug 2003
Posts: 2,135
Likes: 2
From: Dayton Oh
Summit has a 2 1/2" x 14" K&N knock-off filter that I've been using it without issues. However, I don't think that I'd see any noticeable performance differences the way I drive between the 3", 2 1/2" or 2 1/4". Maybe if I was on the strip or dyno then I'd see a difference.
Thread Starter
4th Gear
Joined: Nov 2005
Posts: 4
Likes: 0
From: Sacramento California
I have tried the drop base version and I'm currently using it. The last thing I want to do right is get a new hood (recent projects have zapped most of the car repair funds - ugh). I'll have to give the K&N a shot. Thanks for the help!
Last edited by TheBoar; Jul 17, 2006 at 09:35 AM.
Safety Car
Joined: Sep 2005
Posts: 4,203
Likes: 643
From: Orange County Ca
Reguarding the K&N filter top. I run a 2 1/2 filter on my 69 bb, 390 hp., in order to keep from rubbing the hood. When I ran the car on a dyno, the operator removed the solid top after the first run, and the hp and tq went up ab out 5%. So, I put on a K&N filter top. Ran the car through again to get the carb adjusted to the correct af ratio. With the filter top, the figures were about the same as no top at all, so I think it does help if you have a restrictive or small filter. Also, kind of weird, when they changed to rods to get the "correct" af ratio, it lost power. Best power was when running about 10% richer then "optimum".
Team Owner
Joined: Sep 2003
Posts: 88,393
Likes: 2
From: eville in
Originally Posted by glenkov48
Reguarding the K&N filter top. I run a 2 1/2 filter on my 69 bb, 390 hp., in order to keep from rubbing the hood. When I ran the car on a dyno, the operator removed the solid top after the first run, and the hp and tq went up ab out 5%. So, I put on a K&N filter top. Ran the car through again to get the carb adjusted to the correct af ratio. With the filter top, the figures were about the same as no top at all, so I think it does help if you have a restrictive or small filter. Also, kind of weird, when they changed to rods to get the "correct" af ratio, it lost power. Best power was when running about 10% richer then "optimum".
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Thread Starter
4th Gear
Joined: Nov 2005
Posts: 4
Likes: 0
From: Sacramento California
I acutally talked with K&N. With my 327 at 5,000 rpm, the af on a 14"x3" is 791 cfm. With the 14"x2 5/16" it is 609 cfm. The top adds 169 cfm. So by adding the smaller filter to the top (total of 778cfm) I can get pretty close to the 3". They said that there is 6 cfm per inch squared.