[Papethova]

I recently tried this new Arma carbon fiber intake. I was initially skeptical about this variable valve thing (I felt it was gimmicky) and doubted if it really would show any benefit. The intake arrived and the carbon is exceptional. Aesthetically the pieces are perfect, I cant praise the CF craftsmanship enough. The fit of everything is nice except maybe for the top. It has some gaps and the closed/sealed intake crowd may find issue with that. With the top off it actually has the look of an old school carburetor. For those that arent concerned about an open box or engine bay heat you can run this thing without the top with a nice big K&N filter and it will look great (Im debating this now). I should point out that Arma also makes a non-variable version of the intake but the only difference there is the deletion of the valve below the filter and obviously the lid not having the cutout (since you dont need the vacuum line).

I decided to test it to validate the design and didnt install it until I could get to a dyno. On dyno day the temperature was 90 degrees F and I had to drive over an hour in traffic to get to the dyno. The car had some chance to cool because it was a dynapack so we had to remove the wheels and mount the car. We did 3 pulls on the OEM box and then swapped the intake to do 3 runs with the intake in a non-variable setting (valve completely open from 0 RPM) and 3 final runs with the intake in a variable setting (valve closed at 0-2500RPM then fully open). The current design is an all or none system so the valve is in the fully closed position and then goes to fully open (vacuum assisted). They claim to be working on a motorized version that will adjust the valve accordingly and provide true variability since it can position the valve in various open positions. Arma has even developed an app "Arma ECV" (Android and iPhone) to control both intake and exhaust valves but it requires a wifi module that I do not have yet so other than seeing the interface on my phone I dont have any practical feedback on it.

I didnt know the best way to compare the runs... do you take the lowest run from each group? The highest? Obviously to maximize the number you can use the lowest OEM run against the highest run, but who does that really help?!?? So, I took the average of the OEM numbers (3 pulls) and the average of the rest of the numbers (6 pulls) for comparison. Based on these numbers the intake showed an average increase of 17RWHP and 17.5TQ. In all 3 groups run 1 and 2 were done back to back and we gave an approx 5 min cool down period after run 2 for run 3. Not surprisingly the highest numbers were generated in one of the 3rd runs, and as youd expect the lowest numbers were in the 2nd runs.

The point here though wasnt to gauge how much power the intake was going to make, my goal was to see if the variable aspect would show a benefit. It was clear that the peak numbers were higher with the Arma intake versus the OEM box in every run. These numbers didnt really differ between variable versus non-variable because they come when the valve is fully open. Surprisingly to me the data shows that the car was putting down more power between 0 and 2500 RPM when the valve was closed. The variable intake made more power on the low end over the non-variable intake and they evened out mid range to high end (both making more power than the OEM box/filter).


The only limiting factor I observed was the fan the shop had. It was very small compared to what I am used to and with a better fan I can see better numbers being possible. Especially since the intake has scoops built in.

I dont know how to insert pics so I had to attach them all in the end (sorry)