Air filter discussion

[hotrod 80]

Ok , my engine builder Is working on me about Air filters . I understand the benefits of no dirt in the motor and the wear that it causes , but he is telling me I will make more power with one .

[hjewell2]

He is correct, more so the base helps the transition into the carb

[Captainfab]

I don't think just any air filter and housing is going to make more power. It has to be a housing and filter that is designed to promote air flow not just look good. Back in the early to mid 80's, Edelbrock made a gold anodized aluminum air cleaner that was supposed to promote good airflow into the carb.

[Marv D]

I'm not sure if I will agree or disagree,, but it's just personal experience that sways me ..This is on my big inch small block. We took one of those cool plastic K&N 'Substacks' that is supposed to help direct the air into the carb. I was looking for 5-6HP on the dyno to make some stupid bragging right number. This was a single 1250 Dominator that we had the motor about as good as it was going to get' at 790 HP. We made 6 pulls with faxing Patrick the dyno print out then he would call and dictate jetting / airbleed changes. When we were flat lining just above 790, Patrick said,, 'carb is tuned'

So we started playing with add-ons looking for 8HP
When I put K&N substack on it we LOST 8HP and a/f at peak was exact same. We did see just a few pounds of torque increase in the 4000-6000 range but at peak with different spacers and that 'substack thingy here's what the engine dyno said

A. 786.6 HP @ 7100 (12.7:1 a/f) NO spacer
B. 791.6 HP @ 7200 (12.6:1 a/f) B&B 1" 4hole spacer
C. 784.3 HP @7100 (12.7:1 a/f) add K&N Substack 'air flow director thingy'
D. 797.6 HP @ 7200 12.6:1 a/f) Toss the substack and add DART SuperSucker 1" spacer

Decided we were just wearing the motor out for the sake of finding 3-5HP and decided to leave it alone.

As we know,, peak HP doesn't tell the whole story in the drag strip and average torque does. So here's is 'average torque' for each of the above pulls.
a. 625.5
b. 635.4
c. 629.0
d. 629.6

Controlled dyno sessions doesn't always tell the true story of how things really do on the track, but there is some hard fact numbers to ponder.

Oh as a FYI we dyno tuned without an air cleaner,, it goes down the track without one. I put a carb-cap on the motor between rounds.

BTW,, Merry Christmas guys

[hotrod 80]

I have always had an air pan sealed to the cowl hood . I am swapping to a forward facing scoop for next year . I also had the underside of the hood tinned and an 11" hole cut in it . Space is limited , so I am forced to use a 9" cleaner in a lower air pan I fabbed up . I was going to order the K & N drag race filter ( not the purple oil type ) these are white and you can see throw them . Some thing along the lines of 9" round x 5" tall so it goes up in the scoop . Machinist theory is that it straightens out and stabilizes the air signal . He bought me a Wix paper filter that is 9 3/8s x almost 5 . He is so convicted he paid for the filter .. Guess we are going to real world try it on the 21st of Jan. Currently I open the hood and leave the fans running and drape a rag over the carb .

Next question will a filter change A/F ratio . I see Marv's results had A/F ratio changes .

[vin63]

My results were about 6 BHP on my SBC with my air bell-equipped scoop air pan with filter compared to without on the dyno. Regarding the air filter, in some cases (depending on type of air scoop), the air filter will slow down and smooth out the air flowing into the carburetor(s) especially in an air scoop application where the air can be quite turbulent at speed going down the track, creating poor atomization.

Here's the base of my scoop air pan looked like on my Super Gas car. I ran an air filter on the top side.