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Perrin to AEM..... good swap?

2K views 10 replies 8 participants last post by  MainFrame 
#1 ·
Hey all, I currently am stage 2 on my 11 wrx. I have an invidia catted turbo-back and the perrin CAI. My friend just sold his 14 wrx in which he had the AEM cai on it for only like 3k miles. He told me he would sell it to me for only 100 bucks. But is it worth it? Is better in anyway over the perrin? Or am i just compairing apples and oranges? I have literally ran a perrin intake on all 3 of my wrx's and have always loved them. But I know the AEM one is a good piece too. Any thoughts?
 
#4 ·
Yea I know, but the AEM one comes with that heatshield blocking engine heat from the filter. Didnt know if that would benefit any over the perrin one or not.


And at Tubtub, I have an accessport, but am running a Torqued Performance map.
 
#6 ·
Which version of the Perrin intake do you have?
I have the new design which looks exactly like the AEM and I believe they both use K&N filters.

From reading my intake temps they usually are 10 hotter then what my out side temp sensor reads (i know they are in different locations) If I could I would like to try to fab up a heat shield but I have had no problems with mine. If anything buy it and sell it.
 
#7 ·
I have the older one. With the foam filter. And I know that, power wise, there is really know difference and it is like compairing apples to oranges or whatever other saying you wish to use. The lower intake temp is what I am curious about. Is it enough of a difference to even put in the time and money for the AEM intake. And I have also thought about making my own. My cousin has done several fabrications of intake heat shields for subarus and vw's. So that is always an option. IF, it is worth it.
 
#8 ·
With a custom air intake the dimensions have to be almost perfect.
The biggest problem I have noticed with CAIs is they allow so much air to go thru mass airflow it can't scale the air correctly.

That's the main reason the car has to be tuned with intake. Otherwise the engine will start throwing codes.
 
#11 ·
The biggest problem I have noticed with CAIs is they allow so much air to go thru mass airflow it can't scale the air correctly.

That's the main reason the car has to be tuned with intake. Otherwise the engine will start throwing codes.

That's not really how it works.. the amount of air passing through an aftermarket CAI is virtually identical to the amount of air passing through the stock intake. The issue is that changes in the MAF diameter, location, and air turbulence will throw off readings from the sensor. A mass air flow sensor is basically a small wire with electric current running through it heating it up. As the temperature of the wire increases, so does it's electrical resistance.. the voltage drop over the wire is used to determine mass air flow. More air, means more cooling on the wire, means more current to hold the temperature, and so on.


So it's not really measuring the volume of air entering the engine, it's measuring the velocity and density of the air (denser air removes more heat from the wire). That means if you put the same sensor in a bigger tube, with the same volume of air passing through, the velocity of the air will be lower, cooling the wire less, and in turn causing readings from the sensor to be thrown off.. reading less air passing through the intake, even though the volume of air is actually the same as before. That's why it's important to rescale the sensor for any change dealing with the MAF and how air passes through it.
 
#9 ·
Since you have the TP tune im sure Eric wouldnt mind helping out with a re-tune. Again for the price just buy it and sell it. I look at it this way and it could be wrong. The amount of making it shouldn't matter with temp isolating that much (or it doesnt to me). You always want your car to perform at optimal conditions but I tond think its a big deal at this point. For the price buy the intake clean it up and save up towards a new intercooler that should help your temps more then worrying about a new intake. Even when people go FMIC they dont bother with isolating the intake from the heat since the FMIC will be doing a lot of work. Hopefully this rambling makes some sens or its just my 2 cents.
 
#10 ·
Are you close to maxing out the MAF on your current intake? If not, there's little/no reason to get a different one at this point.
 
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