Would a cone air filter under the nose provide similar gains?

 

If you look back at the first page of this thread (before it was perverted) Dave Greimann gives a good account of his testing process in developing this modification. His experience was that the cone filter plus pipe combination(s) tested did not provide as much airflow as the four 2 inch or larger holes placed in the stock airbox.

If you wanted to purchase or build a manometer and test with a stock airbox and then with the cone filter you might find a cone plus pipe combination that would provide similar or better results. Manometers can be purchased for as little as $20. Certainly it could be a fun experiment.

 

sigh - here we go again

it was not perverted - it was straightened out - your facts are perverted (to use your words) - one more time though, so perhaps you can get it straight

dave is a very bright guy, with a lot of knowledge and expertise, and certainly had a lot to do with this project, and not for a moment do i intend to minimize his contribution, but frankly was not involved in all phases - this was a very long and covoluted process - for example, he was very instrumental in the manometer testing, and final steps, but he had litttle to do with the advance planning, and nothing to do with the dynomoneter testing - many long phone calls between he and i, about the specifics of the final steps, occured as dave and i were each pondering the next steps - we both came to the same conclusions - open it up - then, more phone calls with a lot of "try this and then call me", "test that and then call me", "what did you find when you did this?", and "what do you think about this?", before a final decision was made as to the best setup - who did the physical implentations and where was purely a condition of where the gauge was at that time - had he have still been here, we would have done it together in person, rather than over the phone - the fact is that it got late after doing the testing at my house, and he needed to get home, so the process got continued at his house and over the phone

i now have plans of my own to take this a step farther

to the question, i was specifically interested in the cone setup myself - when i setup the test, decided what to manometer test, and sent dave the spreadsheet of what and how we would be testing, i included that in the testing - together, in my garage, we figured out exactly how to go about the specific testing of each setup, making sure we got the accurate info on that setup, as well as the others - it was a popular design, and needed to make sure we weren't missing anything - that setup is exactly what got dave and i thinking there was more to be had, and that the airbox iteslf was the problem

the results are that the cone showed somewhere around 85-90% of the flow of the setup with the airbox mod - not bad, but not as good

the nature of a tube is more restrictive - there is actually math out there for how much over what length and with what bends - you might get similar flow results if you mounted it directly on the MAF, and the filter you chose had the same exposed surface area, but you would likely not get as much cold air in there, due purely to the location being farther away from the direct flow - not sure how much of an effect that would have though - probably awfully close, as long as you were moving

 

The reason why I ask about the cone is because a 968 engine in a 944 doesn't really give much leway for the 968 air box. Sort of stuck with a cone. Here is my setup:



I am not an engineer nor to I pretend to be an expert, but I do not quite understand how a straight piece of pipe, about 5" long, with a cone air filter with plenty of surface area could be less effective at providing airflow then the stock airbox with a few holes drilled. I might go out and buy a manometer and do some tests... anyone interested?

The car seems to gasp for air WITH and WITHOUT the air filter installed. Would guess that's because of my exhaust. Just trying to figure out how to get more air to the intake (without going forced).

The exhaust does wonders after about 3200 rpm, but low down I know I'm getting hurt. Of course, life is full of give and take.

-Matt

 

5" probably won't show much resistance - i wouldn't worry about that one - we tested a setup like the EVO, which has a much longer tube, and presumed you were talking about something similar

the remaining question now is surface area that is exposed to fresh cold air - less surface area equals less air equals less power, so filter selection here is critical - do some measuring to see where you are in relation to the panel filter area - remember that each fold is more area (this is pretty easy if you are willing to gut a couple of filters and flatten them out)

also, remember that at this point, you are likely only be talking about 1-2 hp difference, and you are way better off where you are now than stock

 

Couldn't agree with you more. Dave is a very bright guy and he has done a wonderful job building some of these products.
I guess its obvious who the engineer is .
Raj

 

funny you should say that - i remember that we actually had a bit of a laugh as we were on the phone working out the last details of the mod, having the same ideas and were nearly completing each others sentences as we discussed it - it really was fun - takes me back to my days as a mechanical designer

 

I guess I wasn't clear enough, I was talking about Dave Greimann.
Raj

 

dres - the bell mouth certainly helps things by reducing turbulence as the air goes in - while i have seen some of the cheaper cones without it, most of the higher end cone filters have this built in - surface area is still a key factor in efficiency though - basically, the larger the better

 

My latest approach to my airflow issue has just been completed. I didn't have the opportunity to use the air-baox cut-out method due to the placement of the intercooler.

So, what we did was to use the area down low in the bumper opposite of the oil cooler air intake location, if you follow me. We have piped down to that area and have a big cone filter sucking up the cold air from that vent. Actually, there is a plate blocking the area, but we've removed it. So, on one side of the car, the vent is used to allow air to the oil cooler(passenger side) and the other side(driver's side) is used as a cold air intake.

Jason

 

lol - cool - i'm going to be doing a similar thing there to change the airflow through the lower part of the chassis

i did think about that though when i first started on the intake project - i couldn't seem to get there smoothly without removing a bunch of stuff

have you had any water issues there? any testing done? that's a long tube with a lot of bends - how did you get around the corners without kinks and restrictions? pics?

 

I'm rather photographically challenged, but I'll try to borrow my son's help and see what can be done.

Jason