K&n filter 502mpi 1996
 

I have stock flame arrester and was thinking of something less restrictive. Has anyone done this?
If so any rpm gain? Thanks

Absolutely DO NOT WASTE YOUR MONEY. I have EXTENSIVELY dynoed a slightly modified 502 mpi the past 2 months, the ugly gen V style/mefi 1/ and 2 454/502 by far outflowed ANY upgraded air cleaner on the market. The hardin kn with square to round adapter killed 30-40 hp on a 540 hp 502, even the vortech engineering/AZSM etc giant billet rectangle version did not come close to the stock early one (with 2 dimples in the cover). You have by far the best factory flame arrestor, even a HP500 efi kn element killed 20 hp over the stock one in my testing, fwiw, Smitty

Total piece of hp killing garbage!

Thank you so much for the info!!

How do I open up your attachment?

Not sure, I attached a picture, as a registered user you should be able to open it. Go down a few threads and read my 502 mpi intake on dyno thread, I was completely shocked as to how good the factory flame arrestor worked and how bad the aftermarket ones are, especiually the oval clamp on version. Now the 98 up gen 6/mefi 3 454/502 flat plate flame arrestor killed hp too. I gutted a early one (shown in the pics) and a fully intact one outperformed slightly it on dyno every single pull.

Here's ArcticFriends thread on all of this and more:
http://www.offshoreonly.com/forums/g...n-my-shop.html

Scott, just made pulls last week now that dynos back up, stock 500efi kn robbed 20hp too, hard to believe the big nasty restrictive looking 502 air cleaner kicks its azz!!!

Amaaaazing!!

Maybe we should just use surgical cotton...for....wait...surgery. LOL.

Remember my test on the 9x4 K&N FA on the small block carb mid 300hp years back ? It lost almost 2mph. Same hr, many runs with vs without, back to back...same section of lake.

When i built my pontiac 462 efi for the 74 trans am a few years ago we were making 575 to 585 or so hp day to day, bolted on kn 3x9 on dyno and made like 537 or so, was 38 or 40 hp drop, put info up on po tiac forums and every guy that had one was mad at me. I was doing them a FAVOR!!

Which is the stock one? ANyone have stock GenV filters? Got one that already had billet filter doodads on it

Keep in mind this was a slightly built 502 w manifold work, bored out throttle body, 500 efi cam, I never tested a bone stock 502, its possible at that low of a hp level it will make zero difference as there might be other things more restrictive.

75.5mph GPS with stock, 15 minutes later, 75.5mph GPS with K&N. No harm or help..

IF. your touching rev limiter stock w current propping OR motor has other things that are the restriction then air cleaner will make no difference, the aluminum adapter for the clamp on kn was so restrictive and hurt air flow so bad on my modded 502 that it drove it 90% into the 90 map table, fwiw, Smitty

I was not on the rev limiter but good idea..

I recall an article years ago where they tested a lot of air cleaners from stock paper to the "best" K&N and others. all were the same size so the only difference was the brand and material. the best one for horsepower was the cheap paper filters, everything else started reducing power.

There is always more to it. A very clean, good paper filter does flow tons of air.....until it get's wet. Humidity and paper don't mix. Another place where a dyno doesn't show real life.

Metal flame arrestors don't swell when wet.

Speaking of which, have you guys seen my picture of shrinking K&N elements ? Yup, the cotton shrinks. Not hearsey - the photo I put up on OSO is one I have here, and I hve seen this a handful of times.

Here, I found the thread I started on this.
http://www.offshoreonly.com/forums/g...-w-photos.html

Not shown on pics is comparison of height vs a new one. About 3/8" in height too. Doh !

This is the K&N 9x4.5" flame arrestor (#59-3364) , which has a 2 3/4" element height.


http://i230.photobucket.com/albums/e.../DSCN21861.jpg

http://i230.photobucket.com/albums/e.../DSCN21871.jpg

I agree with all that, my point was more to the sales pitch of all the high dollar filters and the actual results that are seen. in a boat there is not really any dust and dirt to deal with like in a car and the best is probably the metal screen filter. I personally have never had much luck with the cotton filters or the "trick" air filters and usually just run a good paper element and change them often.

Not with me, and even with what I say against K&N, I use them.

Why ? My driveway and my roads are gravel. During the summer they are massively dusty. Gritty sand dust. I need an air cleaner, and K&N is the only flame arrestor that is one.