Cwarta

iTrader: (12)

Okay as some of you may know I recently switched to a victor Junior intake and four barrel fast throttlebody. I plan to run a conventional style 14 inch air cleaner like found on most carbureted vehicles. I initially thought I was going to run a K&N style washable 14 inch filter with the high flow filter top. Just thinking about the concept what one would think that it would flow a lot more hair than one with a solid lid. well upon doing some research about it I came across a few threads that said people lost horsepower by going with the high flow top due to problems with the venturi and booster signal etc.


They said that the high flow top cost turbulence with the air coming from the sides and messed with the signals. My question is with the fast for barrel throttlebody I don't believe I need to worry about the Venchuri or booster signals. With that being said am I correct in my beliefs? if I am correct then is there still something to be gained by going with the high flow top or would you recommend going with a conventional flattop and maybe a drop base maybe a 4 inch tall filter? I'm just trying to get all my stuff together and make sure that I sacrifices little horsepowers as possible.... Any input is greatly appreciated, thanks.

Current setup

quicksilver383

iTrader: (3)

Turbulence is bad for airflow regardless. That being said, you wont know how that throttle body likes that top until you try.

The stunningman

iTrader: (47)

I have run a high flow top on mine with a boss 429 style scoop... Ram air. I ran it with the air filter assembly and without. It ran faster with the air filter assembly. I have not run with a closed top without a ram air set-up so I have no apples to apples for that one. However I am test and tuning this Saturday non points... so I may put down a pass with one just for the hell of it.

87caprice318

iTrader: (1)

^^^THIS, when I had my car on the dyno he made a pull without the air cleaner, pulled good..then put air cleaner on, pulled BETTER......if that info helps

Doug G

With my old combo (406ci SBC) I always took the filter off at the track (closed top).

I forgot to remove it one day....after a few passes I remember to remove it....no difference

Guess it comes down to your combo and ET ?

LXguy

iTrader: (5)

A lot of people have trouble with that top. I think the problem lies in the way it is run.

The top itself is 1/2" thick or so and reinforced with metal lattice. Most don't take that into consideration, they just slap it on.

A lot of people run drop base air cleaners, it puts the element very close to the venturi, and the top itself ends up serving as a major obstruction to the air coming in through the conventional filter. Most users don't really have a lot of airflow that would come in through the top to offset the other losses, so they end up at a net negative for airflow.

I believe the instructions call for 2 or 3 inches of clearance between the high flow top and the carb.

From the users who have the clearance, and actually have decent airflow to the cowl, I've heard nothing but positive experiences.

FWIW.YMMV. etc.

Steve

JRracing

iTrader: (35)

I run a filter lid on my carb motor with a drop base. The lid is very close to the carb. It runs excellent with or with out it. The car will run the same with or with out a air cleaner on it.

dogsballs

when i was tuning my car recently we tried filter off and on (oversize 10" x 6"). with it on the afr's jumped up 0.4 (leaned out), same power but picked a bit of torque.

newschool72

iTrader: (12)

I had the filter top on my Fast EZ EFI until I built a cold air setup for the cowl hood. I never did any testing to see + or -, but don't believe with the TB it will have much adverse effect with turbulence. On my SBC 406 in my 68 Camaro , I run the filter lid with a drop base bottom, and in a dyno test ,the car put down 3 more HP with the filter top vrs without a filter at all. A small gain , but a gain none the less.

speedtigger

iTrader: (16)

Lots of guys have said they run the same or better with a conventional 14" filter arrangement over no filter at all. I have never tried the K&N flow through filter lid. I might have, but I read too many who said it slowed them down. And, for the cost of that unit, I was not willing to try it.

1981TA

iTrader: (7)

I run with the filter lid, using a modified Trans Am shaker with full time cold air. The car spends a lot of time between 3 and 6k RPMs, and is very responsive. It seemed somewhat choked with the solid lid. My top filter is about 1.5" from the carb - an Edelbrock thunder AVS 800.