Just got my MazdaSpeed CAI!

[quote author=Nymisus link=topic=70133.msg1250854#msg1250854 date=1173150510]
On another note, I noticed when I drove out to the "country" as I was cruising the trip uter went up about 2.5 mpg, although it is almost back to where it was before as I have been stepping on it more and more lately.

Also, on the motor mount deal, whats the difference in the numbers??? Which is best?
[/quote]

Its a debate whats BEST... it comes down to whats best for you....

The stock mounts are mushy and have gaps (non solid)

Any solid poly mount will be good... So technically 62,70, or 88 All good...

The higher the number, the stiffer the mount. The stiffer the mount, the less vibration dampening=more interior noise and vibration.

The 62 being the softest and having the least vibration of the 3, is also the weakest. But in being weakest, its STILL significantly stronger than stock...

70 is a big step up... people report mild vibrations at idle or lower rpm... but a very tough mount, nonetheless...

88 is for the big boys who dont care about vibrations, they would rather have the engine soldered to the chassis.

MAF after a curve on an incorrect diameter pipe: a HUGE no-no!

Yikes! Somebody measure their fuel trims with this intake.


The MAF is mounted after a bend in the pipe which is a HUGE no-no. Actually, it's between bends, which is even worse. Your MAF accuracy is going to be terrible. This intake is producing huge dyno numbers because it is leaning out the air/fuel ratio, plain and simple. While it feel may good, you're screwing yourself in the long run.

In fact, Cobb tuning (respectable company) once tested an intake that put the MAF after a curve. It was an SPT intake, which is to Subaru what Mazdaspeed is to Mazda- an official part. They found that since the MAF was mounted after a curve, it would sometimes report the engine getting less air even as actual air flow ROSE, and vice versa. I'll repeat that: as the engine drew in more air, the MAF sometimes reported a lower air velocity.

The dynamics of the air within the pipe varied according to velocity (think about the air going to the outside of the bend), and since the MAF only reads air flow in the center, the MAF accuracy went to hell. This is why all OE airboxes use a straight velocity stack (off of a huge airbox) and put the MAF directly after the opening. This is also why companies who actually do R&D, like Custom Performance Engineering, use expensive CNC'd MAF housings and air straighteners to get the fuel trims back to stock.

Strike two is that this intake clearly uses a MAF on tube design, and aluminum tube is not sold (at least not cheaply) in specific enough diameters for this to work. Mazdaspeed may have the diameter close, but air velocity is, I think, something like a 4th power of pipe diameter, so even being off a small amount means the MAF will be off by a lot. In the Mazda6 community, every intake used a 2.75 or 2.5" pipe- since neither matched the stock diameter, every intake threw a CEL unless it had a fuel tuner to correct the MAF (no exaggeration, every single one ever released). Now, the Mazdaspeeds aren't as quick to set a CEL, but they are every bit as sensitive to pipe changes, and being DISA turbos, MAF accuracy is even more important than a naturally aspirated engine.

Mark my words: this intake is a mis-engineered piece of crap. You might wonder why I'm bitter, and it's because Mazda puts their name on these ho-hum aftermarket parts. It's a disgrace. The Mazdaspeed intake for the Mazda6 was just a rebadged AEM intake that Mazda marked up for more money, and it too threw a CEL.

This intake will work well on a stock car just because they are tuned so incredibly conservative and rich from the factory, but once ECU tuning becomes available, this intake is going to be an Achilles heal. As I said earlier, this intake will dyno high because it leans out the air/fuel ratio- hell, the worse and intake is in this regard, the higher it will dyno. These are what I'd call ricer gains, because Mazdaspeed intake owners will not be able to use Cobb's reflash nor CPE's upcoming piggyback, at least not without paying for custom tuning and dyno time, and MAF corrections are extremely difficult to do even with a Mustang dyno (which a lot of tuners don't even have).

Those who do run ECU tuners may find their engine detonating or worse, since the MAF, which the ECU relies on for fuel metering, won't know what the hell it's reporting. MAF accuracy becomes incredibly important when you tune an engine more aggressively. Without a way to produce an accurate air/fuel ratio, you'll be forced to tune the car very conservatively- like old turbo cars. The ECU won't even know the true load the engine is under. The intake combined with an off-the-shelf ECU tune will surely produce a too-lean situation since the ECU tune will lean out the air/fuel ratio a few points beyond what the intake is tuning- it won't be able to tell that your car's MAF is off. It relies on it. Hell, that's why it's there. Ten years ago cars, turbo cars used MAP sensors, and they had to be tuned conservatively because MAP sensors aren't as accurate. The Mazdaspeed3 has both, but with your intake messing up the MAF, you're essentially taking three steps backwards.

Anyway, I know everyone's excited because it's a cheap way to make horsepower, but please understand why it makes that power and what the long-term consequences are. If you're fine with buying an intake with the engineering pedigree of one of those "eBay resistors" (they make power the same way, throwing off the MAF!), then go ahead. Free market and such. However, I'd strongly recommend owners instead get an intake like Custom Performance Engineering's, since it keeps your MAF accurate while still alleviating the pressure drop, so it'll be balls-on accurate with piggybacks and ECU reflashes down the road. It's the proper way to tune, with no parts stepping on one another's heels. But perhaps most importantly, you won't have the inconsistent rise of MAF voltage- the CPE intake keeps this sensor linear and reliable. If you don't want CPE's intake, given the current market options, stay stock and see if another decent design hits the market.

Re: MAF after a curve on an incorrect diameter pipe: a HUGE no-no!

[quote author=stretch link=topic=70133.msg1251416#msg1251416 date=1173183447]
The MAF is mounted after a bend in the pipe which is a HUGE no-no. [/quote]
Not sure if you've seen the CPE intake, but it has similar bends.

[quote author=Ferdball link=topic=70133.msg1251496#msg1251496 date=1173190159]
[quote author=stretch link=topic=70133.msg1251416#msg1251416 date=1173183447]
The MAF is mounted after a bend in the pipe which is a HUGE no-no. [/quote]
Not sure if you've seen the CPE intake, but it has similar bends.
[/quote]
...right, much to their chagrin. Ask them how much stuff they had to do to compensate for it! Not only is CPE using air straighteners inside the tube directly after the bend, but that MAF housing is CNC'd to a special size and shape. Air straighteners work, but at the expense of flow. IIRC, CPE put the air straighteners in a larger section of pipe to alleviate the flow issues, followed by the specialized CNC'd housing that tapers down keep the MAF properly calibrated. Maybe they can chime in to explain it better than I can- I know they consider it an utter bitch (lots of painful trial and error) to get their intakes to match the stock calibration, but it really does set their intakes apart from the others.

Anyway, these are things Mazdaspeed is not doing- things that require a lot of time to develop and money to fabricate. The Mazdaspeed intake is just a tube with a MAF mount stuck on, which is why putting the MAF after a bend (especially in an incorrectly sized tube) will produce such undesirable results.

stretch, no offense but do you even own a mazdaspeed 3 and have you seen a mazdaspeed intake. You seem to like trashing products that are sold on this website with no justification. Of course the car will need to be tuned differently if it has a CAI, that is a given. It is ok to lean the car out a little since it comes pig rich from the factory. How do you know the tube is incorrectly sized and that the MAF is in a bad location. You are seriously talking out of you ass here. No offense but I don't know why you are calling the mazdaspeed intake a mis-engineered piece of crap when you haven't even seen it. I also don't know where you are getting your dyno numbers. It sounds like you had a bad experience with the mazda 6 intake and are feeling like the ms3 intake will be the same. Over 60 people have this intake on this site and not one has a problem and I have yet to here a bad review. I am glad that the intake leans out the mixture, because my tailpipe is covered in soot after two minutes of driving and leaning out the mixture is the best way to make power.