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Crushed intake filter? WTH

7K views 84 replies 32 participants last post by  txpsd 
#1 ·
Any of you guys have a problem with the turbo trying to eat your filter?

Afe stage 2. before you go there...its not really dirty.

I'll get a pic. lol. Thing is almost crushed.
 
#41 ·
So. i got some new tires so I finally had the opportunity to drive it "aggressively" on the way into work this morning. With the old PG7 filter, there were some smoke issues when driving in traffic. With the new 5R filter on that problem is solved! Amazing the difference. Way easier to drive in traffic now. EGTs are down too.

I popped the hood when I got to work to check the filter. No hint of crushing.
 
#42 ·
I just run a decent sized K&N filter. My filter is a bit bigger than the one my buddy runs on his 1100rwhp supra running the same GT47-88. I took his filter clean off one time and made a whole -4rwhp gain with no filter at all.

Sounds like you had a crap filter on the truck. You just need something to keep the small children out, lol.
 
#48 ·
Gare, my 5r is crushed, where ya new one from and $$?
 
#51 ·
Fine, I'll just tell'em I want the Garret discount.:evil:D
 
#59 ·
so, am I to believe my AFE stage1 with the pg7 filter w/ prefilter is doing the same thing.:poke: What's the part number to the exact filter I need to swap with?
 
#60 ·
so, am I to believe my AFE stage1 with the pg7 filter w/ prefilter is doing the same thing.:poke: What's the part number to the exact filter I need to swap with?
Um, no. His GT42R is pulling just a little bit more air than your stock turbo. Yours should be fine.
 
#63 ·
isn't that model for the stage2? I think the # for stage1 is 24-40035?

thanks for the post either way.
 
#69 ·
Wasn't aFe coming out with a larger filter similar to the 6637 in size. I seem to recall airflo mentioning it about 16 months ago. I think it was PG7 too.
 
#65 ·
anybody know what the CFM difference is between the pg7 and the pro5? Both these are more cfm than the 6637 right?
 
#66 ·
I think the PG5 flows about 700 CFM. I did some calculations on my 104 Lb/per min Y2K and I needed about 800 CFM to meet it's needs at 100% usage and figured the PG5 would be good for DD.
 
#68 ·
It's a shame that 'sucking in the filter' is the official measurement guideline in place to determine if our trucks have enough filter surface area.

Charles, I can't explain why you lost 4 rwhp when you pulled your filter all I can tell you is that Beddins took several common cone style filters to a flowbench (years ago) and all had significant restriction by the time they hit 500 cfms and my truck picked up several pounds of boost by pulling the airfilter which is why I now run 2.
 
#70 ·
I have no idea. I guess the K&N just doesn't get in the way of the air. Or the dirt some would say. And I wouldn't say it lost hp by removing it. A 4hp swing on 1100rwhp is irrelevant IMO. I considered it "no change".

Now service life I can see being of real benefit, even if I can't nail down any concrete evidence of flow losses. My air filter is COVERED in dirt within a week. Just plain nasty almost immediately every time. But even on the dyno with pinestraw and bugs literally stuck in the pleats it still makes the power. I have never taken my filter of and made a pull because I basically refuse to run my truck with no filter. The charger's just to expensive to have a belt or piece of hose or anything get in there.


As to the airflow guesstimates above, aren't we like, times higher than that? 700CFM? That's not even in the ballpark on a truck running compounds. I would honestly expect a minimum of 1200 to 1400+ CFM flow. And to be honest, wouldn't be surprised at 2000+.

What am I missing?
 
#71 ·
So this was your friend's 1100 hp Supra that had a negligible difference in hp when you guys removed the airfilter? We already covered this if so. Just removing the air filter could have leaned his engine out for instance and he would not have made any additional power for example. That's just one way in which it might not have made any difference. He needs to install a vacuum line on his intake and then tune from there.

What Byron found when he put several air filters on the flow bench was that they began to have restriction anywhere from around 350cfms to the very best (a high efficiency Fleetguard no less) that made it to like 800 cfms before they started to have restriction. The filters continue to flow air after that point and he didn't mention any crushing at all but intake restriction would just continue increasing effectively increasing your PR for the same amount of boost.

PS. In addition to the piss poor filtering capabilities of the K & N's they typically flow less than even OEM filters. Even when jetting is corrected most motorcycles lose hp w/ K & N's drop-ins for example.
 
#73 ·
That supra runs in open loop at WOT. The engine doesn't care what the A/F is. The A/F was unchanged... injector duty cycle, unchanged. Engine airflow....unchanged.

On my truck, going from a filter that's dark black, with pinestraw, leaves and bugs hanging out of it, to a freshly cleaned filter I feel nothing. So how much power are we talking here due to intake restriction?

Fwiw, increasing the PR on my big charger would be beneficial on my truck. The biggest issue for the first stage is large flow at a low PR.
 
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