I am in need of a larger MAF or atleast a larger housing. I was thinking of removing the actual sensor from it's housing and transplanting it into a 4" O.D. tube of some kind. Does anyone know if this is possible or if I can even remove the stock sensor?

 

I've heard of people trying. It's possible, and should work well if done right. You'll DEFINITELY need to re-calibrate the MAF transfer function though in the PROM. And, you'll need to fudge it, while you're at it, to avoid the 255 g/s limit in the software. Basically, to do that, you'll need to lie about the injector flow rate (for example, just enter 1.5 times the size of your injectors), and then begin re-doing your MAF tables and scalars.

If you're not into prom burning yet, you will be after this exercise.

Good Luck! If you do this, and need advice, hit me up on the diy-prom board.

 

You can not take the sensor apart, but you can cut out the sensor from the housing leaving enough of a lip around it to glue it back into a larger peice of pipe. Done right it won't look bad and should work. I don't know how much good it'll do on anything making less than 450 crank horses though. I'm assuming RednGold (who knows much more about this stuf than me) doesn't think you would be lucky enough that a change in injector constant alone would work for the change in the sampling rate. That being the case, if this is your only ride,,,, I'd suggest you get another sensor so you could swap back to stock until you worked it all out.

 

Well, actually, you can:

 

You might want to give a tip or two how you got that apart without tearing it up. Way back in the 80s I either gave up on it or tore the wires,,, seems like it was glued together very well,, can't remember the specifics,, only determining to cut around it. I'm assuming it worked OK after you put it back together?

 

I could tell you, but the men in the black helicopters would have to visit your house tonight.

Patience, care, and precision. There is no glue, only sealant. Be careful not to contaminate the clear thermal gel in the electronics package.

 

Too bad putting it into a bigger tube won't do anything about the 255 g/s measurement limitation. You could put it into a tube the size of a 5 gallon pail and the sensor will still only measure so much air.

 

I am not really trying to modify flow rates or anything. I just wanna try to keep the tube size closer to the 4" of the TB. I mean it goes from 3" OD to 4" OD in the space of 3" in length. What I don't know is if the actual sensor inside the housing relies on the tube size being 3" for calculations???

 

I think you're missing my point. Unless you're doing this purely for appearance purposes, you're wasting your time. The current MAF can already pass more air than it's capable of measuring. Going bigger will not give you any performance gains, and if you've got enough horsepower to consider the stock MAF a restriction, you'd be far better off with a different ECM that didn't use the MAF.

 

I am quite sure I have not exceeded the HP level of the MAF. Based on the mods in my sig I barely have more than stock.
I only want to put in a larger tube for two reasons. One is to maybe get rid of some of the air rush sound I believe I'm getting from the drastic change in size so close together. The other is to be able to get a silicone boot with the right size to seal off the MAF. I am having trouble finding a boot to go from 4" to a little over 3". Silicone boots don't stretch much and I can only find 4-3 right now. The TB is bigger than 4" but I can't change that.

Any ideas

 

Can of worms.

If you were to move the electronics to a different size tube, you'd have to do a bit of work to get the car to run right. Take a look at the picture Vader posted above, that'd be the sensor you'd be modifying... take the brown portion and related electronics, put them in a bigger housing. The way the WHOLE system works is airflow passes the heated wire in the brown portion and that is translated to airflow through the whole sensor. Its a lot of math and theory but basically if you move the sensor into a bigger housing (like from its current <3" to a 4"), you'll end up reporting a lot less airflow to the ecm since more air can pass through that larger area you've created around the actual sensing portion. Now the car doesnt run right because the actual airflow is a lot more than its being told. Clear as mud?
Its fixable, but you'd probably have an easier time finding an appropriate fitting or doing away with the MAF completely than modifying all the parts to work in harmony again.

 

Edit - what Max said - his reply had not posted when I started mine

Yes, moving the sensor from a 3" pipe to a 4" pipe will change the sampling rate. It would require at a very minimum an injector constant change in the chip. If you're going to do this,,, unless you feel you're as careful, skilled, and patient as Vadar (I'm not sure how you would know this - I obviously am not),,, I'd recommend cutting around it. Tape up the sensor and be careful,,, they're not cheap.

If it's boots you're looking for, this place has a wide selection and I've run one of the rubber 4" to 3" hump hoses myself,, fits fine,, just attach the boot to the T/B first then the MAF sensor. You can find cheaper places by doing a Google search for 4" hump hose.

http://store.airflo.com/rubber-hoses---clamps.html

 

One option is to use a small portion of tubing around the ends of the MAF, then put the bigger tubing around that. Its not the prettiest solution, but it works.

 

just a thought, i am also involved in the import world and a common mod is to throw a maf from another car in to accomplish what you guys are trying to do. if enough research is done is there an issue with using another manufacturers maf? alott of people with nissan four bangers use a maf out of a z32 300zx, i wonder if the same could be done, using a corvette or a f body ls1 maf? its funny how a 5 minute job for one manufacturer is a near impossible PITA for another, in the nissan world prom tuning is nearly unheard of and very expensive, a la standalone engine management systems. in the chevy world its semi simple and quite common diy project, and vice versa for maf issues.

 

I would most like to get rid of the sucking air sound. It's not really a flow issure. More looks and sound for me. I'm not at the highest power leveles yet.

 

you should make the sucking noise louder and tell honda kids you have boost, nother option is to use an aluminized hood mat that you can get from summit, ought to cut down on heat and noise from the engine bay

 

Did you remove the air intakebaffles ? They were there to cut that noise. I never noticed this noise that you speak of....

 

Baffles, I don't need no stinking baffles. My setup is not stock at all. I have a Ram Air II hood. That feeds a fiberglass ram air box with K&N filter that flows into a stock MAF siliconed to the box. Then I have a rubber 4" to 3" reducer that feeds into the 52mm TB. So baffles are no where in there, especially since I like horsepower.

 

Been there, done that! I installed the MAF guts into a 3.5" aluminum tube. 4" tube was too big of a transition,, I even cut out the round end of the flow lid, and installed a oval-ized 3.5" tube in to the flow lid. I have a Camaro, and wanted to keep the ram-air setup that I have. Then I have a 3.5" to 4.0" rubber reducer between the 3.5" MAF and my 52mm Twin TB. When you do this, you are changing the reported flow rate by a very larger margin. The engine is actually getting about 35% more air than the MAF reports. So, I
had to burn an Eprom chip with a fuel injector constant of 17# instead of the 24# injectors that I actually have. All in all, its worked out OK,, resulting in my best ever ET of 12.12sec.

 

The other thing you can do is use a late model MAF (much better then the stock Botch unit) and adjustable converter box so you can adjust how much over 255 g/s you want the MAF to register at 5V and lie about the injector constant accordinly. The higher up you go, the worse the resolution gets, but it does work. The other advantage vs. using a pipe is that youll have the flow straightener, which is necessary with a very large MAF.

 

Dude you are complaining about a noise that is an enevitability....because you " like horsepower" .... " suck " it up and deal with it ....it comes with " horsepower " lol

 

yea i didnt know you werent stock,, ever think that the sucking noise comes from having that t rex hood on your car? you have a "ram air" hood, kinda comes with the territory brotha, you could still use the hood mat to cut it down a bit though