Almost two years ago, Cobb Tuning approached the Mazda community and gave hints about releasing products for the Mazdaspeed 3. Cobb, who is a well respected name among the Subaru and Mitsubishi community, has released as promised, those products for the Mazda community. Today, we look at Cobb’s Mazdaspeed 3 SF Short Ram Intake.

1: Velocity Stack

At first glance, it appears to be a simple intake piece. We are all familiar with the assortment of intakes out for the Mazdaspeed 3 today. Some of the intakes on the market today are considered half baked concepts. The inside diameter of these MAF housing vary among intakes. Some, have been known to cause lean conditions within the ECU and created an assortment of driveability issues or MIL codes, which illuminate on your instrument panel. Some of them are just plain junk and are avoided among the community.

So what makes Cobb’s so much different than everyone else? Well, if we look back at the 60′s, a lot of top hot rodders used velocity stacks in their carburetors to smooth the incoming air. A velocity stack is a usually cylindrical tube of some type with a radiused inlet end device. When this device is added onto the air entry location or locations of an engines intake system, it will:

[*] Allow smooth and even entry of air into the intake duct with the flow streams boundary layer adhering to the pipe walls

[*] Modify the dynamic tuning range of the intake tract by functioning as a small reverse megaphone which can extend the duration of pulses within the tract

[*] Alter the dynamic tuning speed (dynamic engine compression) if the overall length is changed thereby changing the tuned length to a lower or higher rpm.

Look at the below image as an example how the Cobb SF SRI works to smooth incoming air into the MAF housing.

The next image below shows you an example of how air enters typical intakes.

Cobb’s velocity stack:

Up: Air Straighteners, Build Material & MAF Sensor Housing

2: Air Straightener

The second piece designed into Cobbs SF SRI, is the air straightener.

Completely unique to many intakes on the market for the Mazdaspeed 3, only Cobb and CP-e utilize this technology for their intake systems. It’s for obvious good reason, right? Of course. Air straighteners perform a very simple function. The design has long enough straighteners in the MS3 configuration, to stabilize the airflow before it goes across the MAF sensor. This promotes a more laminar airflow and essentially creates a much more stable environment for the MAF sensor to sample from. As pointed out earlier, other intakes on the market have proved less than ideal by causing lean conditions. This is contributed to the erratic airflow that enters the pipe, than continues to become more turbulent as it flows across the MAF sensor, causing lean conditions, erratic idling and MIL codes. It’s known that even Mazdaspeed’s own CAI was removed off the market, from owners suffering from these very symptoms.

Cobb Air Straightener

3: Material

The third piece to Cobbs SRI design is the material it is made out of. Every MS3 intake on the market is made of some type of metal. Whether it be powder coated steel, or aluminum, they conduct heat and heat up the incoming air charge before it reaches the turbo. Cobb took a different approach and used a type of composite plastic that best matched the OEM material Mazda themselves use for the stock MAF housing. This decision allowed them to have an intake that would not absorb as much heat coming from the engine bay as a metal pipe, thus allowing for a cooler ambient air charge temperature. Cobb continued with this philosophy by providing a silicone tube that connects the intake housing, to the turbo inlet, thus keeping temperatures at bay as it enters the turbo.

4: MAF Sensor Housing

Now the fourth piece and probably one of the most crucial places in an intake… The MAF sensor housing itself. Data has shown that any fabricated intake system introduces inconsistency in performance due to the manufacturing techniques. The degree, angle, and location of the MAF sensor is critical. Even mounting the sensor at 90 degrees from stock will results in a different measurement. The stock MAF sensors are designed to work in a particular configuration and if the tooling used to position the MAF sensor is not consistent then the measurement from the MAF sensor will not be consistent. Every one of Cobb’s intakes are made with the exact same tooling, no welding, no CNC machining, etc. This allows for a part to part variance that is much less than an intake that requires additional steps to fabricate. Cobb is able to hold very tight tolerances with this injection manufacturing process.

Cobb MAF Housing:

What is the exhaust diameter of the stock mazdaspeed3 exahust tip? I know the tubing is 2.4″ but I want to know the outlet size to get an idea of how an aftermarket exhaust will look on my mazda3.

Answer by Theneelster
Oh really? The mazdaspeed exhaust diameter is 2.4″? Okay…I’m not going there. No…the diameter is 2.5″ because exhaust pipes aren’t made in intermediate diameters (diameters go like this: 2.0; 2.25; 2.5; 2.75; 3; etc.)

The tip is probably 3″ in diameter from what I can judge just by looking at it. Anything bigger would look “ricecanrrific”


New York, NY (PRWEB) March 14, 2014

Last week was a special one for SizeItUp as they finally managed to integrate the data for the 2014 Ford Focus ST into its application guide. This latest addition is a part of SizeItUps ongoing initiative to update the database to include all the latest releases.

is a four wheel drive performance car, with a turbo charged 2.0 liter EcoBoost engine. In terms of price and features, the model measures up very well in comparison to other cars such as the features against the Volkswagen GTI and Mazdaspeed 3. The smooth braking and clutch action makes the 2014 Ford Focus, a very good choice for those going for a vehicle with superior steering. The extra package options include includes automatic climate control, an 8.0-inch touch screen, leather seats, plus amenities such as HID headlights, LED daytime running lamps, and navigation.

Released in September 2014, The 2014 Ford Focus ST receives glowing recommendations from automobile review sites, which is what led to SizeItUp deciding to integrate it. Updating the vehicle database is important, because that way online wheel and tire retailers subscribing to sizeitups solution can provide fitment information to their customers. When purchasing wheel and tires online, owners of the The 2014 Ford Focus ST want accurate fitment information to be available and SizeItUp is providing it for online retailers!

About SizeItUp:

SizeItUp [ is an ACES complaint, fitment database solution provider, for wheel and tire retailers who need an updated fitment guide for their website. Sizeitup has reached over 20,000 vehicle applications for wheel and tire fitment data. From single fitments to staggered fitments, dually fitments, and lifted truck applications, Sizeitup has the largest and most accurate application guide on the market. By continuing to integrate fitment data of popular vehicle models, SizeItUp makes sure that their database stays updated. The guide includes fitment data for the make and model of every car manufactured since the 1960s.