Something to think about before installing intake

[BCMSP3]

Hello, I am new to the forum and recently purchased a 2007 Mazdaspeed 3. I have owned turbo cars in the past and have been doing tons of research before making my first modifications. The link below is a very interesting article from Cobb discussing the realities of aftermarket intakes and where much of the power gains are coming from. Please keep in mind that this article was written for Subaru owners but, in my opinion, applies to all vehicles. I am interested in the opinions of some of the more experienced MSP3 owners here as well. Thanks.

http://www.cobbtuning.com/info/?ID=3223

[Young Roids]

That was a good article. SO the reason that people get better performance out of intakes is because they effectively lean out the a/f ratio and not because of decreased resistance. On the MS3 this might actually be a good thing because they run so rich from the factory a little leaning out would help improve MPG and power.

[BCMSP3]

That was a good article. SO the reason that people get better performance out of intakes is because they effectively lean out the a/f ratio and not because of decreased resistance. On the MS3 this might actually be a good thing because they run so rich from the factory a little leaning out would help improve MPG and power.

I have contacted a Cobb engineer to see if their intake design considers all of the factors in the atricle. I know they have addressed the turbulence issue but not sure about the leaning issue. I am tempted to wait for the AccessPort to ensure it is done right. However, I know an intake isn't a big deal but I don't like having a setup that isn't 100% under control.

[Falconx84]

can't go wrong with cobb, they did take efforts to make sure the AFR was kept close to stock. otherwise, why would Trey Cobb write an article on the importance of having a proper intake? Also keep in mind that our cars respond very, very well to mods whereas subarus NEED engine managment asap

check out www.cobbforums.com for some info, too

[Young Roids]

Since the MS3 runs so pig rich in stock form it would almost be like a poor mans tuning device to get an appropriatly oversized intake on the car to get the A/F ratio we want.

If you get the Mazdaspeed intake for MS3 I am sure it would keep the same a/f ratio it is a mazda approved part afterall.

[Falconx84]

quite the opposite -- it leans out the system

do a search on the ms cai

[Falconx84]

MS3 with MS CAI (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1070&model=speed3)

MS3 Stock (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1080&model=mazdaspeed3+%28%2707+actually%29)

[numbnuts22715]

A/F Ratio of 18???...

[BoostedSpd6]

ive seen the widebands before in a few dsm's and my buddy runs pig rich but his never hits 18 thats just insane.. if that holds true i wanna see it on the guage in a video..please post that up.

[numbnuts22715]

im pretty sure if it was running that lean, itd blow up..
Also, whats with the rwhp reading.. something about that site isnt right.

[rodney]

dude it doesn't matter if you throw any intake on as long as there is no leaks its not gonna run unsafely from a intake and if you want it to run as good as possible then get it tuned, its not as big as deal as they make it and there was no need for them to get that detailed about a freakin intake lol thats just funny, dont get me wrong cobb makes some good stuff but to me that just sounds like there just tryin to push there product(short ram) to sell, i think most of that article was a bunch of BS

[Haltech]

Well i can tell you from a wideband readout that mine didnt change more than .2 pts before and after... My MS CAI did increase the volume of air, cooler air at that, into my engine, instead of having to suck through a straw which gave me loads of more power and efficiency.

Ive never seen an intake lean out it on my truck or mustangs in the past either. SO umm, yeah... Whatever. Perhaps in the import arena, companies get away with making shitty products that do this, but on the domestic side of things, i havent had any issues.

This must go back to Cobbs reasoning of sucking in hot engine air through their Short Ram Intake and trying to convince consumers theres no difference in hp increased opposed to a CAI... Whatever it takes to sell their products i guess.

On several of my vehicles, ive relocated the MAF into the fender well. Again, no lean conditions or tuning issues. So as far as im concerned, this is total horseshit. It doesnt matter if you move your MAF up or downstream, the air is still being metered.

What people need to consider is the quality of the actual replacement MAF tube. If the sensor ( hot/cold wire ) is relocated into a non factory MAF thats improperly designed, youre going to have a shitload of problems. The sample tubes need to be dead on as these are used for proper calibration to your injectors.

As long as a company designed the MAF housing correctly, youre not going to have any problems. I dont think mazda was willing to sell a CAI manf'd by AEM if it wasnt designed properly and causing the cars to lean out. An airflow straightener would help these cars out because of the volume of air the intake side of the turbo brings in. On a Naturally Aspirated car, this isnt an issue.

Take what you want from the article but i find that this doesnt apply to us, the Mazda community.

[Craighjr]

Look at the ms cai run there. The huge drop in power at 2k is the car doing a burn out on the dyno. Or the traction control turning on. That is not a valid run at all. Who would post such stupid results?

[numbnuts22715]

Look at the ms cai run there. The huge drop in power at 2k is the car doing a burn out on the dyno. Or the traction control turning on. That is not a valid run at all. Who would post such stupid results?

lol. obviously he would.
Not saying anything bad, he probably didn't look at them very thoroughly. He posts a lot of helpful stuff most of the time.

But yeah, if any turbocharged car's a/f went to 18:1, it wouldnt be running anymore. anything higher than like 13 is awfullll.
detonationnn!AHH

[funkyman]

The best CAI on the market for our cars at the moment without a doubt is the Mazdaspeed and INJEN who probably is the OEM CAI manufacturer for the speed3&6`s anyway.However INJEN is the only fully Dyno,proven and specifically engineered for the SPeed3`s with taking into concideration pipe size,MAF.Injen is also the newest of them all.
The Injen Technology intake system is a high-performance, dyno-proven system made of CNC mandrel bent 6061 T-6 aluminum alloy. Each intake is carefully engineered for a perfect fit and superior performance. Many other intakes on the market are made of only 3.00" diameter tubes. This may cause friction between the battery and the intake system, dented hoods, or an unbalanced air fuel ratio, which can be harmful to your engine. Injen Technology has taken extra measures to ensure that consumers get exactly what they paid for: Optimum throttle response. Injen Technologies has in-house capabilities for bending 2.25", 2.50", 2.75", and 3.00" diameter tubes on various bend radii.

The SP series from Injen also incorporates MR Technology, an Injen exclusive that stabilizes the vehicle's air-fuel ratio and tunes the intake to be within safe factory limits of performance. Injen tests and tunes every intake for optimal performance. With MR Technology, they take the tuning stage one step further. Typically, vehicles that require MAF sensors have had to simply bolt their MAF sensor onto the aftermarket intake housing. This made for a simple installation, but it changed the diameter of piping where air flowed past the sensor, changing the characteristics of the air-to-fuel ratio the MAF expected to see. This could lead to unstable or lean air/fuel mixtures which can damage high-horsepower or high-performance engines. Injen has carefully tested and tuned their intakes with MR Technology to offer the most stable balance between horsepower and safe operating parameters by changing the diameter of the sensor piping where necessary.

Injen polishes or powder coats every intake for those who are conscious of aesthetics along with horsepower gain. With the use of 1/4" thick 6061 T-6 aluminum and precise CNC machined brackets and adapters, you are guaranteed an exact fit every time. Every Injen air filter is made from highly resistant urethane rubber and comes with a unique built-in velocity stack to smooth the incoming air. A four-ply cotton gauze element filters out harmful particles. Not only does Injen dedicate themselves to making precisely crafted intakes, they also back it with a limited lifetime warranty to ensure a quality intake for years to come.


Features

Approximate performance gain for this vehicle application
Horsepower (HP): +33.36
Torque (ft-lb): +35.16
CNC Mandrel Bent 6061 T-6 Aluminum Aerospace Alloy Construction
TIG Welded Vacuum Fittings & Brackets for a Precision Fit
MR Technology for Improved Air/Fuel Ratio Stability
Injen Urethane Filter with Built-In Velocity Stack for Maximized Air Flow
All Intakes Are CARB Certified, or Are Currently Pending
Rubber Vibra-Mount To Eliminate Damage Due To Engine Torque
Stainless Steel Clamps
Dyno Proven Horsepower!

[numbnuts22715]

lol you sound like a sales rep or something.

I've always wondered why the dynos showed so much more of a gain for the injen...
I think I'm just going to get the mazdaspeed though.

It's hard to believe that a company other than mazdas cai could be better for the car.
But it's what they sell, and cover so that's what I'mg oing to get.

[funkyman]

lol you sound like a sales rep or something.

I've always wondered why the dynos showed so much more of a gain for the injen...
I think I'm just going to get the mazdaspeed though.

It's hard to believe that a company other than mazdas cai could be better for the car.
But it's what they sell, and cover so that's what I'mg oing to get.


No No don`t get me wrong don`t get the Mazdaspeed just because of the name.Probably,the gains are no way 30hp but ,you should never give an hp number with CAI`s anyways,but percentages and any CAI can never give more than 5-6% on a FI engine and 1-3% on a NA engine,thats a fact.However the Mazdaspeed i`m sure is either made by Injen or AEM i will look into it.Just like Porche Calipers as an example are made by Brembo so are most of the Super car breaks etc.As you said most manufacturers talk out of they rear ends just to sell the products,real life numbers are no where near them.
The gain on a Mazda CAI would be no better than INJEN if not less,but its a ripp off because you pay for the name and maybe looks.(yes)

[numbnuts22715]

oh, no. I know.
I wasnt doubting anything you said, and i apologize for the jumbled up post.
It's just hard to believe that mazda would release an intake that could have been made better. From what I have gained from everything that I've read on the forums, the Mazdaspeed intake wasnt engineered as well as it could be, and some other aftermarket companies are putting more effort into it.
I'm just going to get the mazdaspeed one for 1)I dont want mazda to give me trouble about warranty work, and to be honest, that's pretty much it.
I'm not extremely worried about gains, I stillhave to wait for Cobb to come out to see what I can do that with that.

Your post was extremely informative though. Thanks.

[Jays07MS3]

lol. obviously he would.
Not saying anything bad, he probably didn't look at them very thoroughly. He posts a lot of helpful stuff most of the time.

But yeah, if any turbocharged car's a/f went to 18:1, it wouldnt be running anymore. anything higher than like 13 is awfullll.
detonationnn!AHH


If you look at that dyno chart you can see from the RPM axis that he rev'd it up and then let off the throttle at around 3500 rpm and then stepped on it again at 2800 rpm. Whenever you let off the throttle and let the engine coast, the AFR's go super high since very little fuel is being burned. But remember there is NO load on the engine.

This is a log from my dyno run. Look at my AFR (WB OS 1B EqR, purple line) when he let off the throttle at the end of the run. My AFR shoots up to 29!!! That happens all the time when I'm driving. Under partial load/throttle it should be around 14.6-14.7, and only under load should the AFR's go down as the ECU throws more fuel in.

So there is really nothing "wrong" with that dyno run or his car. They just shouldn't have rev'd it up first and let off the throttle. His O2 sensor can't react instanteously so it took a little while after he went WOT for the numbers to come down. No biggie ;)

[Fritch]

MS3 with MS CAI (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1070&model=speed3)
anyone else see that the dyno goes from 2300rpm to 3600 and back to 2800?

wtf is up with that? Kind of screws up the results

[Falconx84]

just to clarify the post as far as I am concerned -- I do not know who's cars they were nor do I know the dyno shop, method used, anything at all about them. I simply did a search for a dyno shop that tested a stock ms3 and an ms3 with only ms cai under fairly similar conditions

I was under the impression that it was a known fact that the MS3 cai DOES lean out the car. Not into dangerous levels, but definitely leans it out as compared to bone stock.

Keep in mind that the article posted was specifically directed to subarus. They are notorious for having all sorts of problems with a poorly manufactured intake. Not all cars are created equal. The only real time you have a problem (as far as MS3is concerned) with leaning out the system to a dangerous level is when you start adding more than just a cai and cbe. The current theory is that mazda pretty much expected owners to add a cai and cbe so they made the afr appropriately rich so as to not end up with problems

Subaru apparently expected owners to keep things pretty much stock, and the stock system works very well together. It's just when you start changing things that they have an issue with engine management. As far as the article is concerned, the subaru stock airbox has a fairly efficient design, esp as compared to the ms3 airbox. This is why they mention the airbox as one of the last items in a subaru-specific build. For an MS3 build, cobb recommends that the intake is one of the first items to change, as the factory box is very restrictive.

does this help clarify anything?

[StealthWyvern]

anyone else see that the dyno goes from 2300rpm to 3600 and back to 2800?

wtf is up with that? Kind of screws up the results



nice catch, but its even more messed up then you noticed. lol

2300 -- 3600 -- 2800 -- 3500

[Jays07MS3]

anyone else see that the dyno goes from 2300rpm to 3600 and back to 2800?

wtf is up with that? Kind of screws up the results

Ummm... yeah, I just mentioned it in the post right above yours.


nice catch, but its even more messed up then you noticed. lol

2300 -- 3600 -- 2800 -- 3500

Yeah, its just because he hit the throttle, let off and then punched the throttle again at 2800 RPM.

[Haltech]

I was under the impression that it was a known fact that the MS3 cai DOES lean out the car. Not into dangerous levels, but definitely leans it out as compared to bone stock.



.02 pts is hardly leaning out the AFR. If you want to lean out a MS3, remove both Cats inline from the downpipe on. The CAI is hardly making a lean condition even worth mentioning. I recorded .2 difference AFR once mine was installed.

[desperado-c]

The best CAI on the market for our cars at the moment without a doubt is the Mazdaspeed and INJEN who probably is the OEM CAI manufacturer for the speed3&6`s anyway....

What are you talking about? The Mazdaspeed for the 6 and 3 is made by AEM, right down to the DryFlow filter. This is the first time I've heard anyone rave about Injen, let alone suggest that they are the Mazdaspeed CAI's manufacturer. No amount of cutting and pasting BS from their online brochure can make them sound any good to me.

[rodney]

What are you talking about? The Mazdaspeed for the 6 and 3 is made by AEM, right down to the DryFlow filter. This is the first time I've heard anyone rave about Injen, let alone suggest that they are the Mazdaspeed CAI's manufacturer. No amount of cutting and pasting BS from their online brochure can make them sound any good to me.

bottom line Injen > AEM intake sorry to bust your bubble

[desperado-c]

bottom line Injen > AEM intake sorry to bust your bubble

Well, at least base your statement on something. For instance, my not being interested in Injen is based on their reputation for throwing CELs at the drop of a hat.

[rodney]

your the first i have heard of throwing a cel with injen, you must of not of installed it right or something, im not trying to dog on you or anything like that but if you have it with leaks anywhere before the mafs you will throw a cel but back on topic...its just my opinion only, you are all entitled to your own opinion i just stated mine

[dkswim]

our car uses a maf sensor and a widepand o2 sensor. im not confident beacuse i didnt weasure the sizes but CAI should be same size at maf sensor as stock box so the car should still be reading corect amount of flow. and car tries to maintain a/f.

[desperado-c]

your the first i have heard of throwing a cel with injen, you must of not of installed it right or something, im not trying to dog on you or anything like that but if you have it with leaks anywhere before the mafs you will throw a cel but back on topic...its just my opinion only, you are all entitled to your own opinion i just stated mine

I just asked you us what you based your opinion on. Sounds like you base it knowing some people with Injens who haven't had problems. That may be the case, but two good engineering firms (CPE and BEGI) have made money by cleaning up the messes Injen has made for some other people. CPE's intake is called the XCel meaning unlike Injen and some others, they test their intakes for CELs and won't release them until it don't throw CELs. BEGI had to add air straighteners to a few of their customers Injens to keep them from throwing CELs. That's what my opinion is based on.

[madeye moody]

dude it doesn't matter if you throw any intake on as long as there is no leaks its not gonna run unsafely from a intake and if you want it to run as good as possible then get it tuned, its not as big as deal as they make it and there was no need for them to get that detailed about a freakin intake lol thats just funny, dont get me wrong cobb makes some good stuff but to me that just sounds like there just tryin to push there product(short ram) to sell, i think most of that article was a bunch of BS

Well if the MAF sampling tube is changed to a different housing then it is going to read different than it did before due to the changes in airflow characteristics. It is entirely possible that it can read it leaner. Most OEM sensor have a housing and those are less sensitive to relocation though they can still have issues if mounted right after a bend in the tubing or similar changes from stock.
I'm a bit surprised that the MS3 intake is just a tube with a bolt in area for the MAF sensor. Crap, if that's all the science there is behind it then you can build your own intake and just retain the portion from the old intake tube that has the sensor mount and you'd likely be BETTER off. I'll have to look at the stock intake closer and see if it can be removed, maf sensors and pipe removed as a unit and reused. In that case I can route my own intake pipe and call it a day.

[madeye moody]

Well i can tell you from a wideband readout that mine didnt change more than .2 pts before and after... My MS CAI did increase the volume of air, cooler air at that, into my engine, instead of having to suck through a straw which gave me loads of more power and efficiency.

Ive never seen an intake lean out it on my truck or mustangs in the past either. SO umm, yeah... Whatever. Perhaps in the import arena, companies get away with making shitty products that do this, but on the domestic side of things, i havent had any issues.

This must go back to Cobbs reasoning of sucking in hot engine air through their Short Ram Intake and trying to convince consumers theres no difference in hp increased opposed to a CAI... Whatever it takes to sell their products i guess.

On several of my vehicles, ive relocated the MAF into the fender well. Again, no lean conditions or tuning issues. So as far as im concerned, this is total horseshit. It doesnt matter if you move your MAF up or downstream, the air is still being metered.

What people need to consider is the quality of the actual replacement MAF tube. If the sensor ( hot/cold wire ) is relocated into a non factory MAF thats improperly designed, youre going to have a shitload of problems. The sample tubes need to be dead on as these are used for proper calibration to your injectors.

As long as a company designed the MAF housing correctly, youre not going to have any problems. I dont think mazda was willing to sell a CAI manf'd by AEM if it wasnt designed properly and causing the cars to lean out. An airflow straightener would help these cars out because of the volume of air the intake side of the turbo brings in. On a Naturally Aspirated car, this isnt an issue.

Take what you want from the article but i find that this doesnt apply to us, the Mazda community.

Amen! I think you are spot on for the most part though it is a bit weird that MAZDA would use an AEM pipe without at least a mesh screen to diffuse the air. I might look into that myself.

[desperado-c]

Well if the MAF sampling tube is changed to a different housing then it is going to read different than it did before due to the changes in airflow characteristics. It is entirely possible that it can read it leaner. Most OEM sensor have a housing and those are less sensitive to relocation though they can still have issues if mounted right after a bend in the tubing or similar changes from stock.
I'm a bit surprised that the MS3 intake is just a tube with a bolt in area for the MAF sensor. Crap, if that's all the science there is behind it then you can build your own intake and just retain the portion from the old intake tube that has the sensor mount and you'd likely be BETTER off. ....

Yeah, I was just thinking about how the MAF is just stuck into the stock box like that while all the aftermarket intake makers had to develop a housing. As far as your other posting on the lack of a straightener in the AEM/MS intake, maybe you could incorporate the stock straightener into your mod? Let us know what you come up with.

[madeye moody]

Yeah, I'll look at it today and see. I didn't really think all these high dollar intakes would "leave it to chance" but with all the people reporting codes popping on with aftermarket intakes, and running leaner on the MS3 intake then it makes me wonder if we can't do a better job of opening up the potential while still preserving the stock metering precision....if one can call it precise.

[dkswim]

ill have to see if i can find it but sport compact car the magazine was going over some of this info on maf sensors. The Q was about a miata but we use the same set up give or take size. I'll see if i can pull up the info and if soo I'll try and post it for you'll

[BCMSP3]

From everything I have learned both from research online and from speaking with a Cobb engineer, I have the most confidence in the Cobb intake. The MAF housing is the same size as stock and the velocity stack takes care of turbulence. I was told by Cobb that from their testing the A/F ratio remains the same as stock and boost increases very slightly due to less air flow restriction. On a customer car, peak boost went from 13.4 - 14.9 psi. Apparently, the customer had the MS intake as well so they ran a couple tests on it and found that the A/F leaned out a bit and boost increased a bit more. The product has undergone a lot of testing and I have confidence in Cobb. Just my two bits.

[Haltech]

From everything I have learned both from research online and from speaking with a Cobb engineer, I have the most confidence in the Cobb intake. The MAF housing is the same size as stock and the velocity stack takes care of turbulence. I was told by Cobb that from their testing the A/F ratio remains the same as stock and boost increases very slightly due to less air flow restriction. On a customer car, peak boost went from 13.4 - 14.9 psi. Apparently, the customer had the MS intake as well so they ran a couple tests on it and found that the A/F leaned out a bit and boost increased a bit more. The product has undergone a lot of testing and I have confidence in Cobb. Just my two bits.


Those tests need to be thrown out. Youre taking a Cobb short ram, on a dyno, hood up and comparing it to a longer cai with the filter at the bottom of the bumper. This isnt a true comparison whatsoever. ill take a CPE product over Cobbs anyday. When a tuner tries to convince you that a short ram intake is the way to go because it doesnt get in the way of their front mount intercooler, you need to consider the reasoning behind it. I dont see CPE throwing a short ram down my throat and for good reason. Their CAI has airflow straighteners and works with a front mount, Nuff said. Cobb may be gods in the Suburu world, but im not buying their bullshit on the Mazda side of things. Logic supercedes sub-standard engineering.

[laloosh]

Those tests need to be thrown out. Youre taking a Cobb short ram, on a dyno, hood up and comparing it to a longer cai with the filter at the bottom of the bumper. This isnt a true comparison whatsoever. ill take a CPE product over Cobbs anyday. When a tuner tries to convince you that a short ram intake is the way to go because it doesnt get in the way of their front mount intercooler, you need to consider the reasoning behind it. I dont see CPE throwing a short ram down my throat and for good reason. Their CAI has airflow straighteners and works with a front mount, Nuff said. Cobb may be gods in the Suburu world, but im not buying their bullshit on the Mazda side of things. Logic supercedes sub-standard engineering.

AMEN

[BCMSP3]

Those tests need to be thrown out. Youre taking a Cobb short ram, on a dyno, hood up and comparing it to a longer cai with the filter at the bottom of the bumper. This isnt a true comparison whatsoever. ill take a CPE product over Cobbs anyday. When a tuner tries to convince you that a short ram intake is the way to go because it doesnt get in the way of their front mount intercooler, you need to consider the reasoning behind it. I dont see CPE throwing a short ram down my throat and for good reason. Their CAI has airflow straighteners and works with a front mount, Nuff said. Cobb may be gods in the Suburu world, but im not buying their bullshit on the Mazda side of things. Logic supercedes sub-standard engineering.

That's cool, just a differing opinion I guess. I asked them about the front mount and they said that the MS intake will work fine with it. Also, the post-intercooler air temps were the same with both the Cobb intake and the MS. Pre-intercooler they found that air temps were obviously a bit higher with the Cobb intake, however that disappeared at 30 mph. I have lots of STi friends who swear by Cobb, so I guess my views may be swayed. I do, however, have a lot of confidence in their engineering. I don't think they would be willing to throw their reputation away to sell a few MS3 intakes. Either way, I think most of the products out there for this car are solid; it comes to personal preference in the end.

[rodney]

Well if the MAF sampling tube is changed to a different housing then it is going to read different than it did before due to the changes in airflow characteristics. It is entirely possible that it can read it leaner. Most OEM sensor have a housing and those are less sensitive to relocation though they can still have issues if mounted right after a bend in the tubing or similar changes from stock.
I'm a bit surprised that the MS3 intake is just a tube with a bolt in area for the MAF sensor. Crap, if that's all the science there is behind it then you can build your own intake and just retain the portion from the old intake tube that has the sensor mount and you'd likely be BETTER off. I'll have to look at the stock intake closer and see if it can be removed, maf sensors and pipe removed as a unit and reused. In that case I can route my own intake pipe and call it a day.

just get it tunned and you won't have a problem at all and if you cant pay to get it tunned then dont get a intake or you can get one and not get it tunned its not a big deal ppl lol

[fourthmeal]

"Tunned" with what, Rodney?

Tuning an engine requires a bit more then a screwdriver these days, unfortunately. Why would you post this?

You need engine management to tune, so are you proposing that everyone who purchases an intake for their car also purchase a tuning solution AND pay to get it on a dyno?

If you are, you can forget about it.

[6262MS3]

I remember reading an SCC "dear dave" article (sept 07) where they talked about maf sizing, they used an MS Cai for a regular 3 as an example showing how it sleeves down to the factory diameter at the maf housing to prevent throwing the readings off. I'd assume they did this for the ms3 intake as well, unless they took into account how it runs pig-rich stock and let the intake lean-out the mixture on purpose. On a warranteed part I doubt they would do anything to shorten the life of the engine.

[Haltech]

It doesnt matter what the diameter of the tube is on the MAF you guys, it comes down to the diameter of the sample tube where the cold/hot wire sits! You can take that MAF housing and make it 90, 100 or 110mm if you want, as long as the sample tube stays the same. That sample tube diameter holds the calibration for the injectors CC rate.

[ssinstaller]

It doesnt matter what the diameter of the tube is on the MAF you guys, it comes down to the diameter of the sample tube where the cold/hot wire sits! You can take that MAF housing and make it 90, 100 or 110mm if you want, as long as the sample tube stays the same. That sample tube diameter holds the calibration for the injectors CC rate.


The diameter of the maf housing has a huge effect on the velocity of the air passing through it, and it will definatly effect the MAF output. A few of the speed 6 guys had trouble getting the car to run right with the 3" maf housing that comes with the ATP kit--and that's only ~.35" larger than stock...

[numbnuts22715]

I thought it was REALLY funny that the person talking about how the op or whoever needed to get his car tuned because of the cai...

hes got a cai, and an exhaust, and under future mods, he has engine management under it...
rofl

[madeye moody]

just get it tunned and you won't have a problem at all and if you cant pay to get it tunned then dont get a intake or you can get one and not get it tunned its not a big deal ppl lol

Hey, when you get time click on one of my links. I AM a tuner...just not for Mazdas. Yes I could tune it out if I had tuning software for a Mazda, or even something simple like an SAFC or eManage, mafia, etc. However, that's just a scaling factor to adjust maf voltage rather than having the maf read accurately. If the position of the maf affects how it reads air mass, then will it be a problem at other airflow values triggered by higher boost levels? What does that do to the load calculations and ultimately the computers ability to meter fuel properly under ALL circumstances?
In my experience maf's that are sensitive to reposition give more driveability issues and those issues don't necessarily go away in all conditions with just a tune.
I think it would be better to get consistent, repeatable results the first time and then a tune would not be necessary for just a darned intake. I would rather spend my money on tuning for higher boost levels not just for inconsistencies in a maf.
Maybe not anyone else's opinion but that's mine.

[madeye moody]

It doesnt matter what the diameter of the tube is on the MAF you guys, it comes down to the diameter of the sample tube where the cold/hot wire sits! You can take that MAF housing and make it 90, 100 or 110mm if you want, as long as the sample tube stays the same. That sample tube diameter holds the calibration for the injectors CC rate.

This would be one of the first ones I've seen to where the housing does NOT affect it.??
I've always understood it that the maf sample tube is proportional to the size of the housing because the voltage it generates is representative of the whole mass of air flowing through the housing at any one time.
Assuming you keep pressure, temperature and humidity constant then the only factor that can influence the mass of the air you are reading is velocity right?
At low engine speeds like idle the velocity is low and the amount of air in the housing (and sample tube) per unit of time is low. At high engine speeds the requirement is greater and the air has to speed up to supply more volume. The sampling tube also has air moving faster in it.
Now you double the housing size but keep the same sampling tube size and what happens? You cut the airflow velocity in half in both the housing and the sampling tube, effectively cutting the voltage in half that the computer sees from the MAF and making it think the airflow is reduced and running leaner.

[rodney]

"Tunned" with what, Rodney?

Tuning an engine requires a bit more then a screwdriver these days, unfortunately. Why would you post this?

You need engine management to tune, so are you proposing that everyone who purchases an intake for their car also purchase a tuning solution AND pay to get it on a dyno?

If you are, you can forget about it.

"if you cant pay to get it tunned then dont get a intake or you can get one and not get it tunned its not a big deal ppl lol" meaning buy a engine management..or you dont have to get it tuned at all it doesnt effect your car that much i have been running my injen intake with no problems at all so if your gonna make a big deal out of it and don't want pay to buy enginemangement then DONT GET A INTAKE

[fourthmeal]

That's like using an impact wrench on an watch screw. Its a bit overkill. The right way is to have an intake that doesn't manipulate the MAF's size from factory specs. Thus, the OE accuracy doesn't change.

[Falconx84]

all this fuss over a fucking article written for SUBARU

last I checked, I don't have any stars on my hood emblem... this is a mazda forum, right?


In this technical article we are going to discuss the type of intake air cleaner system used on the 2002+ factory turbocharged models from Subaru, the potential problems that might arise from modifying it, and potential solutions.

Please note that the content of this technical article is specific to 2002-newer Subaru factory turbocharged vehicles including the WRX, STi, Forester XT, Baja Turbo, and Legacy GT Turbo/Outback Turbo. The systems used on other year models and non-turbo versions do differ in design and the information included here does not apply.

[rodney]

That's like using an impact wrench on an watch screw. Its a bit overkill. The right way is to have an intake that doesn't manipulate the MAF's size from factory specs. Thus, the OE accuracy doesn't change.

dude dont get a intake if your gonna wine about how your intake isnt like factory to fix your problem just dont get one and you already made it obvious that you dont wanna buy EMS, the end

[Haltech]

The diameter of the maf housing has a huge effect on the velocity of the air passing through it, and it will definatly effect the MAF output. A few of the speed 6 guys had trouble getting the car to run right with the 3" maf housing that comes with the ATP kit--and that's only ~.35" larger than stock...

Than the sample tube where the meters's hot/cold wire reside, isnt designed properly.

[Haltech]

This would be one of the first ones I've seen to where the housing does NOT affect it.??
I've always understood it that the maf sample tube is proportional to the size of the housing because the voltage it generates is representative of the whole mass of air flowing through the housing at any one time.
Assuming you keep pressure, temperature and humidity constant then the only factor that can influence the mass of the air you are reading is velocity right?
At low engine speeds like idle the velocity is low and the amount of air in the housing (and sample tube) per unit of time is low. At high engine speeds the requirement is greater and the air has to speed up to supply more volume. The sampling tube also has air moving faster in it.
Now you double the housing size but keep the same sampling tube size and what happens? You cut the airflow velocity in half in both the housing and the sampling tube, effectively cutting the voltage in half that the computer sees from the MAF and making it think the airflow is reduced and running leaner.

Well you are correct about the housing size. Any company who is engineering a replacement piece needs to design the sample tube for the proper calibration to the size of the external tube. For instance, if you were looking at a 90mm tube, your sample rate would need to increase whatever percentage your upgrading from. Alot of this can be calibrated via software with a piggy back system because it is voltage.

This is the point i was bringing up that as long as that person/company scales the design correctly, you wont have an issue. Unfortunately there seems to be absolutely no QC in place for some of these people releasing parts.Than you have another problem. Companies using a blow through maf opposed to push through. The area in which the sample tube is placed determines the air velocity. If youre running the incorrect type of meter for your application, this will really give you some erratic idle behavior, surging, popping and sputtering during part throttle. Its the nature of the beast unfortunately. I also see that as we begin to push more power after we solve the fuel problem, we will need a custom calibrated maf to keep us from pegging the meters. +4.7 Volts are going to come fast once we bolt up bigger turbo's.

[blacksheepms3]

MS3 with MS CAI (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1070&model=speed3)

MS3 Stock (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1080&model=mazdaspeed3+%28%2707+actually%29)

call me crazy, but those links show ms3 lost power after putting in ms cai. anybody can confirm?

[Haltech]

call me crazy, but those links show ms3 lost power after putting in ms cai. anybody can confirm?


I dont know what they have going on over there, but those are the weirdest set of numbers ive seen so far. There isnt one person here with a MS3 that has reported lower horsepower from a CAI install that ive seen or searched for.

[BONES_GOT_BOOST]

call me crazy, but those links show ms3 lost power after putting in ms cai. anybody can confirm?

that is what most cai's do they may gain a couple of peak horsepower or ft/lbs but you lose alot of power through your powerband. put stock up against ms cai in a 1/4 mile and the stock would win.the torque and hp curves prove it in my opinion.

[dkswim]

say what...... you broden the power curve soo much with the cai install. its not just a peek gain its a gain all over the spectrum and you gain half a grand of power on the botom and on the top.

[mazdaspeed32007]

no kidding ^^^ people have proven with dynos on this forum that the ms3 CAI runs nearly 250 whp from a stock 230 (ish). over the spectrum of the dyno the results were def noticeable not in the initial rev of the engine but about 3000>. the hp just goes up and up and up as the high end reaches its limits to power drop off.

and for the record a MS3 with a stock intake will DEF not beat an MS3 with a CAI. how the hell can that make any logical sense? seriously guy....you gotta be kidding me. even the dyno's that were f*cked read better whp and tq gains across the board for the CAI. i just needed to post something to this ridiculous-ness. dear god.

[madeye moody]

Well you are correct about the housing size. Any company who is engineering a replacement piece needs to design the sample tube for the proper calibration to the size of the external tube. For instance, if you were looking at a 90mm tube, your sample rate would need to increase whatever percentage your upgrading from. Alot of this can be calibrated via software with a piggy back system because it is voltage.

This is the point i was bringing up that as long as that person/company scales the design correctly, you wont have an issue. Unfortunately there seems to be absolutely no QC in place for some of these people releasing parts.Than you have another problem. Companies using a blow through maf opposed to push through. The area in which the sample tube is placed determines the air velocity. If youre running the incorrect type of meter for your application, this will really give you some erratic idle behavior, surging, popping and sputtering during part throttle. Its the nature of the beast unfortunately. I also see that as we begin to push more power after we solve the fuel problem, we will need a custom calibrated maf to keep us from pegging the meters. +4.7 Volts are going to come fast once we bolt up bigger turbo's.


ah, okay I see where you're coming from.

[BONES_GOT_BOOST]

stock
Max (RW/FW)HP: 240.0 @ 5300 rpms
Max (RW/FW)TQ: 248.4 @ 4900 rpms

ms cai
Max (RW/FW)HP: 234.3 @ 5400 rpms
Max (RW/FW)TQ: 250.2 @ 3900 rpms


lost 6 hp gained 2 ft/lbs

and it looks like the dyno is messed up on the cai run. but i am not spending $300+ to lose 6 hp. just for something shiny under the hood.

[MAZDARacing2007]

well its been proven many times that a CAI helps, thats one dyno run^^ and i dont think that all the people with a CAI would have spent the money on it if it was just for an "engine ornament",

yes that dyno run was probably messed up,

Im not trying too be a smart a** but, i dont think all the stuff about the MS CAI in the magazines would have been wrong.

IMO

[dkswim]

hay bones do you have the dyno run graph? im currious to see this beacuse all the graphs ive seen multiple cars added 20-30 HP and its not just a peek adder and we keep breathing up past 6 grand unlike stock which has problems after 5.5grand. i dont remember the torque gains off top of my head.

[AutoXRacer]

I'm installing my MS CAI this weekend... I was going to dyno the pre and post install, but I really don't feel like spending $120 or so on dynos when what really matters is the dyno butt... :)

[Ferdball]

MS3 with MS CAI (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1070&model=speed3)

MS3 Stock (http://www.dynoperformance.com/dyno_details.php?make=mazda&dynorun_id=1080&model=mazdaspeed3+%28%2707+actually%29)

Wow. That was my car with the screwed up dyno. Something weird happened during the pull that made a loud clicking sound. ZooZoom thought it might be pinging, but it sounded more like arcing to me. The next run was more stable.

Basically, we had three different cars show up on the same day.
GotNoSpice - CPE CAI - 228 Horsepower, 243 Torque
ZooZoom - Stock - 240 Horsepower, 249 Torque
Ferdball (Me) - MS-CAI - 235 Horsepower, 251 Torque

Don't know why ZooZoom's car dyno'd higher. But he did put on a Cobb SRI recently, and his dyno's (different shop this time) were a little more realistic.

For more info, check the thread at the other forum:
www. you know who .com/index.php?topic=73457.msg1303756