I see that most drag cars don't. The little "racing" I did last year, I didn't use one. I now have a hood scoop on the Dak and was thinking of buying a K&N 11x4 3/4 filter with one of their filter lids. That way I could still get lots of air {more than with what I use now} and it would be filtered pretty good. Or would that be choking it too much? What do you guys prefer?

I have no room for one.

i would never run without one. i have too much $$ invested in my engine to be neglegent & allow some stray piece of crap get sucked into my motor & do hundreds of $$ worth of damage. an air filter is like an insurance policy for my engine. i don't care if it is robbing power but with modern filters i doubt if it sucks anymore than 1 hp.

I would like to run 1 but just have no room unless I cut up the hood and have some thing sticking up out of it.

you'd make more power sucking in cool fresh air disturbd, i think my 340 picked an average of 0.15 et when i opened up my hood.

Nope...... no room

I did a test this year...one run without the air cleaner and one with, the runs were 5 minutes apart. The car ET'd exactly the same. So I just keep the filter on.

When I made a couple of passes with the Road Runner last summer, I kept looking at the six pack setup and that restrictive looking repop Fram air filter. So I took the lid off and the filter out for one pass and I ran the same exact ET as with it on.

Yes.

I don't run an air filter on the track. Not enough room. But I stick a small one on there for street driving.

I just make sure I am out in front when racing so I don't consume any dust! LOL.

Absolutely! This engine cost way too much to run without one, and it is a mild build compared to many here.

David Vizard in his book "Tuning BL's A Series Engines" felt that in a road race, whatever difference between an engine with an air filter and without, the engine without would lose more power due to increased wear over the course of the race than the filtered engine would lose due to the filter restriction.

I think you are on the right track. put the biggest filter on you can.

There is always dust, grit, rubber bits, small children running around, all of which can be sucked into your engine.

I don't run one, but not by choice - I just have no room.

I clean mine out from time to time and wouldn't think of running without one

I guess i'm neglegent for not running a filter, I have no room unless I cut the hood more and remove some of my windshield.

When I first got my car running with the new chassis I chased a problem where the car would not ET what it should. I had removed 400 lbs and the car still ET'ed the same as it did before I did the chassis. I replaced the distributor, the MSD, I tried jetting, different launch, new wires. Lot's of things. Finally I borrowed a carb from a buddy. My air cleaner would not fit on his carb, it was too small and the vent tubes hit the air cleaner lid. I had too small of a element in it due to hood clearance issues. The car picked up .4 I put my carb back on and left the air cleaner off, it still ran .4 better than it did with the air cleaner.

I didn't run one again until last year. I changed the hood and did a bunch of things to the cowl area to get a bigger air cleaner on it. I only made one run last year so I did not test back to back with and without the air cleaner. It did run very well on the one pass I made with the cleaner on it. If I ever get it out this year I will make the test, I hope it runs the same. I hate running without one but slowing down .4 was huge!

I have always ran an air filter. Like others have said there is to much money invested not to. You never know what might fly in there. I've had my windshield pelted by rocks and rubber on several occassions when behind the water box. I run a Uni Filter. When we dynoed the engine several years ago, it made no horsepower difference with or without it. The filter is 10.5" wide and 16" long. It fits nicely in most hood scoops.

There is alwasy room for filters somewhere:

http://www.telusplanet.net/public/zbhansen/EFI/Engine/SB408EFI_Grill.jpg

And cool air don't hurt either.

Greg

I run one.

I now have room where I can run an 11x4 3/4" {or slightly taller} filter. I plan on getting a K&N filter with the filter lid. With the 4 3/4" height, it will put the lid right up into my new scoop. That was the whole idea of adding it. I know it will make a huge improvement from what I have now. It's just a stock 3.9l filter assembly with a 3" inlet and 2 1/2" tall.. I've raced with and w/o it. So whatever changes I make should be an improvement.. Here's the new scoop.. The hole in the hood is about 15" square.

My car only makes like 450 hp at the wheels.....but I have done a lot of testing on the chassis dyno, and on more than one occasion I've make chassis dyno runs with and without the 14"x3" fake K&N sytle filter and everytime I do it I get the same hp and A/F ratio with and without it.