So I've been looking into intakes for my 09 Lancer GTS, and I'm having problems deciding between short ram and cold air. Short ram gives you more low end torque and cold air gives you more high end HP. I like both, but I dislike the idea of extra noise/growl the intake will cause.

So in looking for a friends Mazda3, I ran across a Cold Air, Short Ram intake kit. It had a k/n filter that sits in the same place as a cold air intake, working much the same. The pipe leads to an "air box", that then leads to the intake. It also has the advantage of not increasing the engine noise due to the intake length + reducing in air speed entering the engine.

From what I understand, cold air intakes work by lowering the temperature of the air by taking it at a point away from the engine heat.

Short ram works by taking the air at a close source to the engine intake, by using a large diameter pipe to reduce air speed, causing static pressure to rise and dynamic pressure to fall, which is where the power comes from.

The cold air short ram system works by having the filter lead to a sealed air box larger than the dimensions of the pipe (about 2x). This gives you the benefit of a short ram intake by reducing the air speed (a.k.a reducing the dynamic pressure of the intake which due to its inverse relation to static pressure, causes static pressure to rise), but has the advantage of the cold air intake by taking the air in the box from a source away from the engines heat.

I'm not the brightest guy, but It seems to make sense to me.

So unless I'm missing something, I'm thinking of manufacturing one myself. I'm hoping to buy a cheap intake off ebay (someone used a Mazda3 intake and modified it, I was thinking the same), and building a larger diameter airbox to stand between the cold air intake with a k/n filter and the engine intake (and the pipe containing the throttle body and MAF sensor).

Technically, this is very similar to the way our cars are stock, which is why I think intakes don't really give you much extra power compared to other cars (at least by the dyno's I've seen). By making it custom, I move to larger diameter piping and a better filter, giving better airflow and lower air speed, hopefully getting both low end torque, high end hp and no added noise.

Thoughts anyone?

Or, you can just buy a drop in filter and bypass all the headaches, noise, and possible SES problems you will be having by going bigger on piping and what not.

Like you said, intakes don't give you much power so why bother. Bigger piping and "better" filter wont do much. If it did, I think K&N, Fujita, Weapon R, Injen, AEM, etc. will make 4 inch pipes. The additional air box just sounds like wasted space; unless your explaining an ice box type design, it sounds totally off.

The air box is to slow the speed of the air down. the piping from the engine to the air box would be the same diameter as the stock to hopefully not cause a CEL and have the TB and MAF sensor mounts.

I could probably make all this and get the filter for the same price as the drop in filter, and the DIY aspect and extra power w/o extra noise idea sparks my interest. Getting the benefit of the SR and CA intakes in 1 seems pretty interesting.

I've seen intakes give up to 15hp at the wheels depending on the car, engine displacement/stock intake. I don't think our intake is very restrictive, so improving on it only gives gains of less then 10, probably closer to 5. I'm also thinking of having a custom exhaust made to give better airflow once I have the intake.

What I'd love to do is have 2 people, 1 with the RRM SRI, one with the injen and then custom make this crossover. Take one of the cars, dyno it stock, then with the 3 intakes all on the same day and figure out the real performance increases. It would be cool to see if the CA/SR actually gives you the benefit of both

Anyone in the maritimes have the RRM/Injen and know where theres a dyno?

I have the Injen and the dyno claims 10 HP and 11 TQ. There is no known dyno for the RRM SRI though.

I do like the idea of the ice box though. Boosted performance and no extra noise.