AEM dryflow filter for PRL HVI intake

[timestamped]

Hey guys, sharing this AEM dryflow filter I just test-fitted with the PRL HVI:

21-2093DK

The PRL filter specs:

PRL on the left, AEM on the right:

Because the AEM is half inch shorter, it seems like it can maybe be pulled without removing the entire airbox which would be nice. Edit: nope it can’t

Haven’t installed yet, just mounted to the velocity stack, put inside the box and covered the ECU-side lid to check clearances.

While the PRL filter has to be stretched a bit onto the velocity stack, the AEM goes on loose and then snugs up once the clamp is tightened. The AEM filter has a nice double ridge the exact width of the clamp that holds it in place on the filter while tightening.

Cheers!

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[timestamped]

 

[nattypiso]

Interesting! My PRL filter is due for a cleaning and was just looking to get a secondary filter. I might just switch to the dry filter, really don’t like dealing with oil for the PRL filter as it’s just an extra annoying maintenance task.

 

[Tw1stedlog1k]

I was looking into something like this as I was not looking forward to disassembling the PRL for maintenance.

 

[Doskiller]

Nice find ............. ;-)

 

[CTR]

Nice! Thanks for sharing.

Does the filter webbing look to be about the same depth? How about the number of pleats? That half inch might not seem like that much but it could add up to a decent amount of surface area reduction.

 

[timestamped]

Nice! Thanks for sharing.

Does the filter webbing look to be about the same depth? How about the number of pleats? That half inch might not seem like that much but it could add up to a decent amount of surface area reduction.

Good questions, I have no doubt the PRL has greater surface area, but even if they were identical dimensions an oiled filter will have slightly better flow / slightly worse filtration than a dry filter.

But for fun, I did some quick and dirty cone math. Not accounting for pleat number and depth, the lateral surface areas are roughly:

AEM filter: 80.2836 sq inches
PRL filter: 81.96 sq inches

Regarding the pleats, the AEM has 51 pleats with about 9/16” depth, while the PRL has 70 pleats of about 7/16” depth.

Multiplying the pleat number by 2 (in and out) and depth, you get the following “pleat multipliers”:

AEM: 57.375
PRL: 61.25

And multiplying these by the pleat length, you have roughly:

AEM: 57.375 x 4.205 = 241.26 sq in
PRL: 61.25 x 4.7434 = 290.53 sq in

This does not take into account the curves in the valleys and crests of each pleat which are wider on the AEM, or that the AEM pleats are spaced farther apart, each of which might make for better flow through a single pleat.

Feel free to check my work, but yea the PRL filter has greater surface area and I would guess better flow than the AEM. Does the AEM filter provide better flow than stock? I would presume so.

 

[nattypiso]

Good questions, I have no doubt the PRL has greater surface area, but even if they were identical dimensions an oiled filter will have slightly better flow / slightly worse filtration than a dry filter.

But for fun, I did some quick and dirty cone math. Not accounting for pleat number and depth, the lateral surface areas are roughly:

AEM filter: 80.2836 sq inches
PRL filter: 81.96 sq inches

Regarding the pleats, the AEM has 51 pleats with about 9/16” depth, while the PRL has 70 pleats of about 7/16” depth.

I didn’t go deeper into calculating surface area while factoring in pleats, but if you multiply the pleat number by 2 (in and out) and depth you get the following “pleat multipliers”:

AEM: 57.375
PRL: 61.25

Feel free to check my work, but yea my guess is the PRL has greater surface area.

Appreciate the data! Though it’s barely shorter in height, I think the type of filtration material and design is more important over how much surface area is available. I mean Eventuri’s filter is visually a smaller design compared to PRL’s, yet it still does the job from the testing I’ve seen online.

But for our Type R’s, it has a turbo so I don’t think we would even notice the “restriction” from that .5 inch difference, since the compressor wheel can spin so fast, it’s gonna get the air it needs regardless of whatever restriction is in front of it.

Maybe for N/A vehicles, there would be a slight difference in performance, but I’m sure there’s some science to it that I don’t know about haha.

 

[timestamped]

There’s also the 21-209EDK, but definitely won’t fit with the lid on. Seems like only half inch clearance from the lid to the top of the 21-2093DK, it must press up on the PRL filter.

 

[Doskiller]

Good questions, I have no doubt the PRL has greater surface area, but even if they were identical dimensions an oiled filter will have slightly better flow / slightly worse filtration than a dry filter.

But for fun, I did some quick and dirty cone math. Not accounting for pleat number and depth, the lateral surface areas are roughly:

AEM filter: 80.2836 sq inches
PRL filter: 81.96 sq inches

Regarding the pleats, the AEM has 51 pleats with about 9/16” depth, while the PRL has 70 pleats of about 7/16” depth.

I didn’t go deeper into calculating surface area while factoring in pleats, but if you multiply the pleat number by 2 (in and out) and depth you get the following “pleat multipliers”:

AEM: 57.375
PRL: 61.25

Feel free to check my work, but yea my guess is the PRL has greater surface area.

Thanks for taking the time to do this. Is this forum great or what ......... ;-)

 

[Doskiller]

Now PRL needs to come with their carbon fiber box and we are all set ......................

 

[timestamped]

Updated “data” with very rough “pleat math,” not that it matters much

 

[CTR]

Thanks for all the info and the extra math! Seems like a 17% reduction in flow area which might matter but I doubt it on a boosted application. I think I might pick up the dry flow filter just to reduce the amount of maintenance. I've heard oiled filters can also damage/throw off the MAP sensor.

Have you confirmed if you can remove the AEM filter through the front inlet or do you still need to use the side access?

 

[timestamped]

Thanks for all the info and the extra math! Seems like a 17% reduction in flow area which might matter but I doubt it on a boosted application. I think I might pick up the dry flow filter just to reduce the amount of maintenance. I've heard oiled filters can also damage/throw off the MAP sensor.

Have you confirmed if you can remove the AEM filter through the front inlet or do you still need to use the side access?

I’m dumb, I forgot to test if the filter can actually fit through the front inlet, I was just thinking about whether it could come off the velocity stack. I’m actually skeptical it will fit thru but unfortunately that’ll have to wait a couple weeks til I’m back in town.

 

[Doskiller]

Now PRL needs to come with their carbon fiber box and we are all set ......................

This could be it ......... about 11:21 into the video ..........

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