Thread: POD filters performance myhtbusted!

Pod filters/CAI are one of the mods that supposedly doesn't relly help much on the performance side. Sure, they makes your engine bay look better, gives better sound but when it comes to performance, they can REDUCE horsepower. Take a look at this MCM Mythbusting episode, wich compared filters/install methods with dyno proven numbers..

N/A cars:
Turbo cars:

Is it worth spending money on performance filters/expensive piping? You decide...

like i tell all my friends. Any change you do to a motor you have to tune it to get the power out of it

Lets all go back to our factory intake box!

NAH!

I will be keeping my JWT Pop Filter.

Yep, most people get them to just clean up the engine bay.

However, what if I told you there is no such thing as a high flow catalytic? There is going to be anarchy and flaming all over the place right. Well if you go talk to anyone that knows (truely knows) exhaust all of them will tell you a cat is a cat is a cat. There is no such thing period per federal admission and CARB.

To truely make an exhaust less restrictive you need straight through exhaust or larger exhaust.

Don't believe me just go do a google on "High Flow Catalytic Converter Myth"

MAP cars do require a retune because VE has changed. But knowing most street modders, that don't retune, this is a good enough of a test.

Flow stacks will make a nice difference, not 10% increase but when your counting ponies it all adds up.

Second video is definitely an interesting, I am surprised the intake block off plate lost power compared to no block off plate.

Finally some of my own numbers. T25 at 9psi on Calum RT ecu. These runs where done with no filter. I should mention the JWT run was not fair at all, I used a DE Pop on DE maf with E60 maf (pictures later), which caused some serious restrictions to flow.


Now if you look at the AFR map it all starts making sense. The flow stack increased the AFR's, that's why it made more power. No tune adjustments where done in this test. Runs where side by side too.



As what I did with JWT maf to get it on the E60 maf...



You can see from the dyno, the DE MAF is a restriction if you use it in front a higher flowing maf like the E60.


Finally I installed the filter on the BPi Flow stack and did a run.


Gained another 3whp


Basically the filter itself has a cone design and helped smooth out the airflow even more.

On the cat thing its a yes and no. I generally will go for a cat that has a larger frontal surface area. You can find these cats made for larger displacement motors.

Its like this if you have a surface area 1 x 1 and you have one that is 2 x 2 the larger surface area will flow more.

You just proved the point that for anyone to see significant gains, you need to tune for the particular intake you run, MAF OR MAP. Not all intakes are created equal. Thus, you've already debunked the this thread and the OP's comments. Of course they don't ADD anything if you just drop them in. You need to tune for it.

One thing the Subaru community seems to know up front: If you modify ANYTHING related to the performance of the car, you need to tune it.

Indeed, though the stock ECU is able to compensate a ton if you have a MAF. But to see any real gains a retune is a must. On my wife's car, once I get a tunable ECU in, I will be able to do virtual dyno logs. Thus I plan on doing side by side runs after installing intake, header, and comparing to see if little mods like that actually give enough power to justify them without a retune. Or if stock ECU that is fine tuned is enough in itself.

Sorry for the big picture quote, but this one is very cool. JP did some dyno testing of timing advances and other mods.

I'm pretty confident now that Vadim is stealing parts from Doc's time machine for these tests.

Pig didn't want to give up the flux capacitor, I did get a miniature turbine engine!




Finally the thrust core, you can see the fuel igniter in the middle.