Intake Question...Gas mileage

We've come a long way from the days when the intake was a big round air cleaner that drew air directly from the engine compartment. When I started owning cars, there were no computers or electronics of any kind, and engine components were designed to fit the car more than perform as well as possible. That's why we could do something as simple as flip the air cleaner lid and get more horsepower, or change the mufflers to glasspacks, etc. So little engineering was done by the manufacturers. That's why you had big V8s putting out 120 to 200 HP and getting 8mpg.

If you look at the intake on the CX9, you see that it has a CAI already: A large air scoop above the grill, then a wide cross section tube into a good sized air box, with generous filter area. Then a 4" insulated tube all the way through the MAF sensor, and around into a composite intake manifold, before entering the engine. Other than being slightly crooked, Mazda did everything to make sure the ait entering the engine was as cold as possible.
Bolting on a short metal tube with a cone filter inside the engine compartment is going to INCREASE the temperature of the air, not decrease it. Denser air does, indeed, make the CX9 run slightly better, but the only way to get it, is to move to a lower elevation, or somewhere a lot colder.

An oiled filter MAY give you a slight boost, but only slight. I use them more for that fact that they filter better with less restriction, particularly as they get dirty. Paper filters start clogging and reducing air flow with each particle they trap. Oiled filters keep breathing, until they are black and gooey. Then you just clean and re-oil them. with 23k on our '9, I have cleaned it once, so far, at 20k.

There just isn't any such thing as bolt on horsepower for modern cars, unless you replace the entire intake and exhaust systems, adjust the valve and ignition timing, and reprogram the computer to the new component specifications. That's why fart can exhaust systems usually make the cars you see them on even slower, and puffing out smoke.
 
There just isn't any such thing as bolt on horsepower for modern cars, unless you replace the entire intake and exhaust systems, adjust the valve and ignition timing, and reprogram the computer to the new component specifications. That's why fart can exhaust systems usually make the cars you see them on even slower, and puffing out smoke.

That's not exactly true... A good example of this is the Speed 3. It's as modern as you can get with a turbo charged direct injection motor. An simple CAI on the MS3 yields an avg of 20WHP and a DP (down pipe) for another 20-30WHP. Both bolt ons with no reflash necessary. There are plenty of Dynos on the forums to back this up.

I agree with you that whatever bolt-ons available for the 9' at the moment (intake) may not do much. However, if someone or some tuner was to spend a bit of time analyzing this car, I am sure he can identify a few bottle necks/governors. Hard to imagine a 3.7L, 10.3-1 compression, DOCH V6, with VVT is only putting out 270BHP.

Anyone who's interested in modding their 9' stay tuned.... I am in contact with a local tuner/engineering firm who has expressed interest in taking a close look at the 9' and its Duratec 3.7.
 
I agree with benben01 on this one.
If you don't mind enduring the noises (or some would call that "music to their ears"), there are some stuff you could do to increase horsepower. Basically, through better engine breathing, which tends to be louder. Manufacturers have to make a trade-off. The mass public do not want high noise-level. CAI, for example, allows more air to get in, therefore, more engine noises to come out also. It is a trade-off.

I was just showing that the air that goes into CX9 is already nearly as cold as your ambient temp. If you want colder air, put an A/C on the intake.... just kidding.
 
You just made my point, though. The add ons for the Speed models are engineered by Mazda to fit each car exactly and make improvements where they knew it could be done They know their cars better than anyone, and have the tools to properly design and engineer upgrades. They also do more than just bolt on new parts. They also re-tune the control systems to take advantage of them, which garage mechanics can't do, even if a part is well made.

Most after market parts don't have that expertise behind them, and are really only made to look (or sound) cool.

I'm not denying that it's possible, but it takes a lot more than slapping on some Checker/Kragen/Schucks/O'Reilly's cosmetic part on a car.

My advice has always been to leave a car alone until you can afford to install functional upgrades with proper tuning. That's all.
 
That's not exactly true... A good example of this is the Speed 3. It's as modern as you can get with a turbo charged direct injection motor. An simple CAI on the MS3 yields an avg of 20WHP and a DP (down pipe) for another 20-30WHP. Both bolt ons with no reflash necessary. There are plenty of Dynos on the forums to back this up.

I agree with you that whatever bolt-ons available for the 9' at the moment (intake) may not do much. However, if someone or some tuner was to spend a bit of time analyzing this car, I am sure he can identify a few bottle necks/governors. Hard to imagine a 3.7L, 10.3-1 compression, DOCH V6, with VVT is only putting out 270BHP.

Anyone who's interested in modding their 9' stay tuned.... I am in contact with a local tuner/engineering firm who has expressed interest in taking a close look at the 9' and its Duratec 3.7.


Speed 3 FTW!! I've got a MS3 in addition to the 9. The Speed3 is more fun to drive, but the 9 has so many luxury features that's it's fun in its own way.
 
FYI.. just replaced the stock air filter with a K&N drop in. Low end grunt is defnitely noticable. Good mod for $50 plus you can just wash and dry the filter when it's dirty. Also, changed my oil @ 900 mark with 5w-30 Valvoline Full Syn. Engine definitely revs more smoothly. Got a chance to do a WOT run on the way to work this morning. Very impressed with the power of the CX-9. May have to make this my DD over my modded Speed3 ... LOL
 
I am close to sea level I guess. I live in the suburbs of MD 30 mins north of DC. As for the K&N install... 5 mins literally. Pop off the clamps on air box. Take out old filter. Put new one in and clamp air box together.
 
We're a mile up. I didn't see that much difference with the K&N, but again, that's not the main reason I put it in. Even with better flow we simply don't have the air density.
 
We're a mile up. I didn't see that much difference with the K&N, but again, that's not the main reason I put it in. Even with better flow we simply don't have the air density.

Youd be surprised, in most cases the paper OEM filter outperforms a K&N, but I agree the K&N is more cost effective. I do like the idea of taking out the noise baffle. Generally, these do help midrange torque, but there primary purpose is to reduce intake noise. I would be interesting if anyone had an hard dyno data on this mod
 
Even if a paper element has better flow than a K&N when new, it will immediately start decreasing air flow as it gets dirty. K&N's don't.
 
My 9 has 2100 miles on it now and the last 1500 on a K&N. No difference in the MPGs. However, throttle response is noticably better and a little more grunt.
 

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