Something to think about before installing intake

[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 ******* 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

MS3 Stock

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 ****** 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.