MAF sensor

Ok me and my friend were looking at the metal braket where the MAF sensor plugs into and were wondering how come it gets so damn small in the middle. My intake goes from 3 iches to a tiny ass bottle neck of about 2 inchs and back to 3 again. My question is are there any mods that make that opening bigger, like a replacement bracket and is this restricting air flow. Thanks for any info.

It actually doesn't really restrict airflow. As small as it seems it actually flows air pretty well. It's not worth it to upgrade until you are maxing out your airflow (somewhere around 8psi?), basically, either a BIG shot of NOS w/ the JWT kit or a turbo kit...

Justin's right. It's not worth it to make the hole bigger. I know you could hook up a Maxima MAF with a huge opening BUT your engine won't take in anymore air than metered. You have to have the ECU re-programmed to bring in more air.

Originally posted by Blue93G20
Ok me and my friend were looking at the metal braket where the MAF sensor plugs into and were wondering how come it gets so damn small in the middle. My intake goes from 3 iches to a tiny ass bottle neck of about 2 inchs and back to 3 again. My question is are there any mods that make that opening bigger, like a replacement bracket and is this restricting air flow. Thanks for any info.
My thoughts exactly! :D

Im in the process of making a MAF bracket that will accomodate the 3" thru all the way. The prototype shown has a 3" piece of aluminium tubing that Ill affix to the bracket that bolts onto the JWT POP. I still need to cut the 3" hole on the mounting bracket and make a housing for the sensor, or ghetto rig the sensor to the tubing.

http://files.automotiveforums.com/uploads/588751Outline1.jpg

Also,Bo-ogie informed me that the 2000+ G's come with a 3" MAF. A new 2000+ MAF (3") from the dealer runs about $250+ :(

The only issue i see with that is the maf is designed to sense how much air passes through an opening that is X size... so it calculates that if the air is this dense (A), and moving this fast (B) through an opening this size (C) the total amount of air going into the motor is (D). Now, if you change the MAF it'll see A B and D the same, however you'll change C and that'll affect how much air the ECU thinks is going into the motor. If that makes sense.

my mistake a botched post....

Justin: I dont know if they take into account the diamter of of MAF, I believe it just measures the velocity of the incoming air. I took the MAF out of my car when installing the POP and the sensor actually sits inside a smaller hole (5/16" about) seperate from the hole that the air actually passes thru. Eventually the air that goes thru the small hole meets up with the rest of the air passing thru...this an image looking thru the MAF...what you are saying definatly makes sense but Im just not too sure what difference the larger thru hole will make. In theory there should get a better air flow without the restriction. I guess Ill find out...
http://files.automotiveforums.com/uploads/860519MAF.jpg

Yeah, but if you change the shape and size of that whole MAF piece the airflow will slightly change, possibly enough to throw the readings off? You figure even a little bit of airflow change can add up to a lot considering that it's a little bit of air going over the sensor, but the ecu multiplies that to take into affect all the air that doesn't pass by the little sensor element.

I remeber seeing someones site and they affixed the sensor to the bracket that HS provides (the upper right hand piece in the previous photo) Without any kind of shielding around it like the stock MAF provides, this is what I am going to do. It seemed to work for them, Ill let you know what happens...

Are you sure they weren't referring to the air intake temp sensor? that's a small sensor that plugs into the intake, that in many cases needs to be custom fabbed to fit (depending on what intake you buy)

Im positive it wasnt the intake temp sensor, they mounted that on the top of the filter in their POP application. It was definatly their MAF sensor that they mounted to that bracket.

Originally posted by Yahnozha
Im positive it wasnt the intake temp sensor, they mounted that on the top of the filter in their POP application. It was definatly their MAF sensor that they mounted to that bracket.

Monkey see, monkey do? :)

I highly doubt you saw the MAF mounted to the filter. In the OBD-II cars you mount the air temp sensor to the filter. Mounting the MAF element to the filter would totally screw things up.

Feel free to screw things up though.

Originally posted by P10DET
Monkey see, monkey do? :)
Hey!!! I resemble that remark!!! :)

Originally posted by P10DET
I highly doubt you saw the MAF mounted to the filter. In the OBD-II cars you mount the air temp sensor to the filter. Mounting the MAF element to the filter would totally screw things up.

Your right I didnt see the MAF mounted to the filter. I think you mis-read that, or I didnt explain properly. The air temp sensor was mounted to the top of the filter.

The MAF was mounted after the filter on this piece that attaches to the POP and then leads to the MAF. They simply bypassed the stock MAF housing and placed it there.

http://files.automotiveforums.com/uploads/788666HSPiece.jpg

Geroge: Honestly, what do you think of this? The 2000+ G20's come with a 3" MAF and the last piece of this assembly I am making will utilize the smaller hole that the sensor rides in. The only thing I have left is to blueprint the "foot print" of the sensor it self, theres a little o-ring seat that needs to be accounted for, amongst other clearence issues...

Originally posted by Yahnozha
Your right I didnt see the MAF mounted to the filter. I think you mis-read that, or I didnt explain properly. The air temp sensor was mounted to the top of the filter.

The MAF was mounted after the filter on this piece that attaches to the POP and then leads to the MAF. They simply bypassed the stock MAF housing and placed it there.

I've also seen kits that place the temp sensor there as well. In fact, that is a better place to put the temp sensor than on the filter itself.

Originally posted by Yahnozha
Geroge: Honestly, what do you think of this? The 2000+ G20's come with a 3" MAF and the last piece of this assembly I am making will utilize the smaller hole that the sensor rides in. The only thing I have left is to blueprint the "foot print" of the sensor it self, theres a little o-ring seat that needs to be accounted for, amongst other clearence issues...

My honest opinion is that unless you are cranking out some healthy boost, you are better off spending your money elsewhere. Mike Kojima installed a Maxima MAF (large bore) in his Project SE-R and saw absolutely zero gains. This is with a 200 crank hp engine.

If you want to go to a bigger openning for whatever reason, just get a Cobra MAF. You'll need to get your ECU reprogrammed, but you will need to do that with any MAF swap or modification.

I honestly think you are asking for trouble. You'd probabaly better price out a replacement MAF before you do something you'll regret later. It will probably cost you close to the price of a header or set of cams to replace it.

Geo is right (duh). The sizes of the holes are very important, change either/or and you have screwed up your MAF calibration.

A 2.25" hole is good for 400+ HP to the wheels. Don't think that size matters that much, especially for NA engines. As a matter of fact, you want things to be the smallest possible to support the HP you are making, this keeps up velocity. Velocity is key.

Wow this is nice to know, thanks for all the help i was just wondering if that restricts airflow, but apparently it doesn't. Thanks

Originally posted by P10DET
I honestly think you are asking for trouble. You'd probabaly better price out a replacement MAF before you do something you'll regret later. It will probably cost you close to the price of a header or set of cams to replace it.
Cool, I do appreciate your honest, and much respected viewpoints...