Filter Restrictions..

DaveWertz

Active Member
Established Member
Joined
Mar 24, 2019
Messages
421
Location
Hughesville Pa
Lets talk about this. Hopefully someone has some real world date to back this. This is the filter I was running on the end of my power pipe, no name off the shelf filter at autozone. Dont know exact measurements or CFM but I can't imagine it flows well. Anyhow with my draw through setup and being in a pinch, this is what I was able to fit at the time. Since going with a FMIC and a new tune next Friday I added a 12" K&N. Its a monster and should flow well. But getting to my point is do you think this filter could have robbed PSI? I just emailed my tuner to have him send me my boost numbers and where my timing was on my last dyno with my old setup and this filter...

I know its a long shot but does anyone have any real data showing the filters can rob PSI on blower setups....?







upload_2021-3-19_6-47-55.png
someone has
 

01yellercobra

AKA slo984now
Established Member
Joined
Oct 5, 2005
Messages
21,128
Location
Cali
I think you can connect a vacuum gauge between the filter and blower inlet. If there's a restriction it'll show up as vacuum.
 

Slow 99

Nothing to see here
Established Member
Joined
Sep 12, 2019
Messages
387
Location
California
I was going to run something like this mounted directly off of my procharger cause I hate the plastic powerpipe it comes with. I was looking into high flow filters in that exact shape cause I don't like the idea of the mesh screens people do for a daily driver aspect cause one semi big pebble and say goodbye to your impeller. It needed to be short enough to not make contact with my radiator and I think I found some options. Of all places, doc race filters for their bmw turbo kits are actually the perfect size and another company also sells something like it as well. If a turbo can spool with the filter on and make up to 900 hp in some cases, it must be a good flowing filter
 

CobraSam

Well-Known Member
Established Member
Joined
Apr 26, 2020
Messages
418
Location
Mass
I run a goofy filter setup on my ProCharger foxbody. It’s stupid large, but it flows really well. It’s an AEM pro flo. I can tell u that I did loose about 1 pound of boost with it on as apposed to a mesh style turbo screen/filter. My car makes about 21psi and about 750hp.
This is comparing open blower inlet to having a filter on it, so of course there will be a restriction. From memory I wanna say it ended up being about 1-2 psi.
 

Attachments

  • AD28D55C-A135-4700-AD9C-7666DFA5FDC5.jpeg
    AD28D55C-A135-4700-AD9C-7666DFA5FDC5.jpeg
    116.4 KB · Views: 103

DaveWertz

Active Member
Established Member
Joined
Mar 24, 2019
Messages
421
Location
Hughesville Pa
Interesting. I'm curious to the numbers I'll see on my this upcoming dyno session. My tuner still hasnt gotten me my old numbers, but id assume I lost some psi through that tiny ass filter I was running. Maybe not allot but definitely some.
I run a goofy filter setup on my ProCharger foxbody. It’s stupid large, but it flows really well. It’s an AEM pro flo. I can tell u that I did loose about 1 pound of boost with it on as apposed to a mesh style turbo screen/filter. My car makes about 21psi and about 750hp.
This is comparing open blower inlet to having a filter on it, so of course there will be a restriction. From memory I wanna say it ended up being about 1-2 psi.

Sent from my LM-Q620 using the svtperformance.com mobile app
 

DaveWertz

Active Member
Established Member
Joined
Mar 24, 2019
Messages
421
Location
Hughesville Pa
It probably murdered your air flow potential. That thing looks like it might be ok on something making 150 HP.


Sent from my iPhone using svtperformance.com
That is probably all it is good for. I did not think about it then as I didn't really think the size of filters mattered much. That and my MAF pre blower it didnt leave me much room for a big filter in my fender well.
 

SecondhandSnake

Well-Known Member
Established Member
Joined
Jan 29, 2011
Messages
1,743
Location
Columbus, IN
I don't have any hard data I can share but generally think of it this way- your power adder (whether it's a blower or turbo) is all about pressure ratios and efficiencies. Pressure ratio is outlet pressure over inlet pressure (in absolute.) As you restrict your inlet, your inlet pressure drops. If you keep your pressure ratio fixed (likely with a mechanical blower), that means your outlet pressure will be lower as well.

Of course as to whether it impacts it appreciably depends on the flow rating/curve of the filter. If you're way over the intended limit, you could have pretty high restriction and it will impact boost. If you're not exceeding it, then you won't really see an impact. Unfortunately not a lot of filter manufacturers publish flow numbers, and they can vary wildly based on filter material and test conditions.
 

DaveWertz

Active Member
Established Member
Joined
Mar 24, 2019
Messages
421
Location
Hughesville Pa
I don't have any hard data I can share but generally think of it this way- your power adder (whether it's a blower or turbo) is all about pressure ratios and efficiencies. Pressure ratio is outlet pressure over inlet pressure (in absolute.) As you restrict your inlet, your inlet pressure drops. If you keep your pressure ratio fixed (likely with a mechanical blower), that means your outlet pressure will be lower as well.

Of course as to whether it impacts it appreciably depends on the flow rating/curve of the filter. If you're way over the intended limit, you could have pretty high restriction and it will impact boost. If you're not exceeding it, then you won't really see an impact. Unfortunately not a lot of filter manufacturers publish flow numbers, and they can vary wildly based on filter material and test conditions.
Based on the filter I posted above, do you think that blower was being choked? I have a feeling it was.
 

SecondhandSnake

Well-Known Member
Established Member
Joined
Jan 29, 2011
Messages
1,743
Location
Columbus, IN
Hard to say without knowing your power/flow numbers, but if you were making enough power, I think it's very possible. Even with that media being as porous as it is, it's not a lot of surface area.
 

Users who are viewing this thread



Top