MAF Intake

[solidaxel]

What is the closest distance you can mount the MAF to the throttle body and still work properly

[dman1982]

good question...

[BR3W CITY]

GM wants 10", I've about seen 5-6" work in a pinch, but that was on a straight section of tube off the front of the tb. The maf wants smooth air, so it wants to be on a straight shot of pipe, far enough from the tb that it won't get turbulence.

Can it be done with less, yes, but you sacrifice some accuracy to do so. On a stockish swap that "just has to fit", then its not a problem...but something being modded, tuned to max effort etc will suffer from it. If you have a tight clearance problem, and are still looking for power, you can consider running SD and eliminating the MAF

[Andy4639]

My 6.0 install. It runs just fine, is it a full all out performance machine no. Can I tell that it doesn't run to it's fullest... no! But BR3W CITY is correct in what he said though for a all out get every bit of performance out of it you can. Then no it's not the best way to set it up.

[solidaxel]

I have another build going on and we have vertical space, and the B H Custom air box would work, BUT I do not think the MAF will work, still looking!

[Jmiller022]

Go speed density with your tune and do away with the MAF

[Iceburgh]

explain speed density ...I have no clue hat that is?
Thanks

[BR3W CITY]

The MAF uses the data from its vain and the IAT (included in maf) to gather an input figure, and it uses that data to help populate VE tables that the engine uses (for lack of a better word, the tune) to make power.

The thing is, you can use physics to mathematically achieve the same results. Something something something inert gas law something something something thermodynamics something something somethings horsepower. Essentially, to remove the MAF you can seperate the IAT and run a MAP sensor. This data plugged into an equation, along with engine RPM calculates the theoretical amount of air entering the engine at any given time. Technically speaking, there is greater "resolution" to this because the PCM isn't constantly fudging back and forth trying to achieve peak efficiency.

SD tunes give the max hp for any given condition, with the caveat being that the tune is way more "Static" than a MAF tune. Because a MAF reacts to changes in air volume, it can make changes to compensate for vast changes in weather, air density etc. SD tunes cannot do this in the same way, so a car SD tuned in Gainsville FL in summer will suffer power loss if raced in fall in Dorchester MD. Above about 750hp, the GM MAF loses its ability to accurately measure air volume and a specialty unit or an SD tune must be considered.

Help any?

[Root2812]

This is really interesting. I's going to swap a 5.3 and will have clearance issues. My project isn't about power but more about cruising. Would this SD tune be something that I could do and not see a noticeable power loss in casual driving? I might romp on it once and a while but I don't plan to go racing. Really its just going to be for car shows and to take my family to get ice cream on summer days.

My other plan is to go with one of those S&P Maf/air cleaner combos that mount right on the throttle body. Of course that would keep the Maf much closer than 10 inches. Anyone have any comments on these units?

[Jmiller022]

http://www.pcmforless.com/index.php?...ning&Itemid=56

speed density vs MAF

[GCncsuHD]

Originally Posted by BR3W CITY

GM wants 10", I've about seen 5-6" work in a pinch, but that was on a straight section of tube off the front of the tb. The maf wants smooth air, so it wants to be on a straight shot of pipe, far enough from the tb that it won't get turbulence.

Can it be done with less, yes, but you sacrifice some accuracy to do so. On a stockish swap that "just has to fit", then its not a problem...but something being modded, tuned to max effort etc will suffer from it. If you have a tight clearance problem, and are still looking for power, you can consider running SD and eliminating the MAF

This is pretty much it. The main key is to reduce the turbulence so that the MAF can get a good reading, preferably in a straight shot of intake tubing. This is much more important if you have a "screenless" MAF. If you have a stock style with the honeycomb screen LEAVE THE SCREEN IN, it straightens the airflow for a better reading. Those are the ones that can usually work decently the way Andy has his, though not optimal, it will usually be OK that way. The ones without a screen will typically be all over the place if mounted like Andy's, but are usually fine if mounted in an ideal straight piece of intake tubing.

Speed Density is always an option, especially if space is an issue, or a cleaner look is desired (or for more precise tuning flexibility on forced induction or high HP builds), though for a daily driver with a mild build, especially one you like to take road trips in I would stick with MAF as the SD is sensitive to weather and elevation changes.

[Daaaanz67]

How about this and change to SD.

[Daaaanz67]

When I build my 56 thinking of this route and having ls performance and old school look.

[solidaxel]

Originally Posted by Andy4639

My 6.0 install. It runs just fine, is it a full all out performance machine no. Can I tell that it doesn't run to it's fullest... no! But BR3W CITY is correct in what he said though for a all out get every bit of performance out of it you can. Then no it's not the best way to set it up.

Andy,
Are you still running your MAF next to the intake or did you move it to the center of the tube?

[Andy4639]

Still there. Hasn't seem to hurt it. The motor is all stock and runs good for me. I don't race it I don't even spin the tires on it. You can see in the picture that the tube isn't straight at all. I guess at some point I should try and figure out some other way but for now it seems fine.