Can somebody splain why, cause I 'm not quite sure I understand. The last time I went to the1/8" mile strip, I removed the air cleaners and the car ran about 2 tenths slower than with them in?



See car mods below

My best guess would be because your letting dirt in with you A/F mixture and it makes for worse combustion. Kinda like a K&N filter helps becuase it keeps more dirt out than a regular filter. Just a guess though.

Hey Dude

My car has the stock (restricted I know!) dual air filter plastic intake system + K+N filters--modified MAF (Bosch).

One other person had a possible explanation, that with the amount of airflow with the filters in place --at WFO--the amount of gas being dumped at max matches the amount of air coming in.

With the filters removed there is an increase in airflow volume and even thought the Maf sensed that, it was pumping at max, which he said means that possibly a slight increase in fuel pressure at the AFPR, or in the chip programming, would be able to take advantage of the increased air flow and keep the correct air/fuel ratio.

Now, if that is so, I need to figure out if this IS what is happening.

I guess the first and easiest thing to do is check the fuel pressure and try increasing it and see if it runs any better?

Anybody have any other suggestions?

Thanks,
Craig

Becuase air flowing in a striaght line is faster than turbulent air. If you take off the air cleaner you the air entering the intake is very turbulent so not as much can enter. As well as cleaning the air,. the filter helps straighten the flow out.

Think of 100 people running at one door, how long it would take them to get through. Now line those 100 people up in single order, they get through much faster and more efficiently.

Nice analogy

Yes, it is a good analogy, and I completely understand the theories/concepts, ETC. I have years of roundy round racing experiance including crew chief on a top local late model and a season points winning sprint car.

I am running a tpi not carb. For that matter years ago whenever I took my carb car to the track and removed the air cleaner, it always ran faster, with or without the velocity stack.

In this case with the TPI OEM plastic air intake system that has a couple feet of "runner" (for lack of a better term) before it gets to the MAF, I'm not sure that turbalance is the culprit, but then again if I knew what was going on here, I wouldn't be asking these questions!

Thanks for the ideas--open to any and all ideas and theories!

adambros, that explanation is worth a million words..I can't see anybody NOT understanding that concept after reading that.

I agree, think it's just s imple case of the hot engine bay air getting tumbled around with the air seeping in around the hood, wheel wells, under car disturbing the air flow.

I've run my car with the $3 air cleaner and it puts up the same numbers as it does with the breather off, but I also have the carb sealed to the hood and sucking through the cowl only for fresh air.

Bests:
60' 1.480
1/8mi. 6.977 @ 98.52mph
1/4mi. 10.985 @ 122.10mph
All through junk paper air cleaner and mufflers

Pretty impressive #'s DUDE!!!

I could easily run high 10's consistently in the summer with a cam swap since the one I have is so mild, but I dont wanna lose the daily driver, drivability I have now.

Nothings better than spotting a BBC powered gutted race car with open headers Street driving I run 92 octane as well as many non points events I drivve the car to the track for, but when I goto the track racing for points I opt for 110, cuz it smells good

How close were the runs together? Any cool down time? Other than that, I'd say the other explanation sounds good. Its wierd, everytime I take the filters out, the car runs about .1 quicker. Hmm....

Three runs--about 15/20 minutes apart--normal cool down for me--relatively cool weather/air--low 70's--late afternoon early evening-- runs were in this order, 2 runs with--3 runs without--4 runs with--all within a 3 hour time span.