MAF's
 

Noob question here....


Can a mafless tune be done on my car? (2005 GTO)


If yes, is it an advantage to go without one?

I am pretty sure you can get a speed density tune, I dont see why not.

If you go MAFless then you'll need an SD Tune, these are often easier with highly tuned setups as they actually work with less information/data due to not having a MAF this in turn makes it easier. However due to not having a MAF you will need to tune for every induction/exhuast mod as the PCM will not be able to automatically adjust in the same way as when using a MAF. This is the same issue the guys with the new "Hemi's" are having as they use SD setups from the factory, but even a CAI/catback really needs a tune.

Thanks for that info!


Do you know if a SD tune will cost me more money vs a regular tune?

I want to get everything tuned at once after I get my H/C setup on!

Why would you want to ditch the MAF?

there is no reason to ditch the MAF unless you are making huge power or your tuner is too lazy to recalibrate it.

I don't see why it should cost anymore to tune using SD. PatrickG (a mod) uses a SD setup on his 470rwhp h/c combo it might be worth sending him a PM (he really know's his stuff). :)

I was just looking at those OTRCAI's...


Most of them are mafless and it seems like it would be hard to shove a MAF in there...


Here is a pic of what I am talking about:
http://www.marranos.com.au/images/otr/otr1.jpg


If that can be done for the right price I think I will buy one... What do you think?

If you replace the MAF with a pipe/hose, there will be less restriction, but you will lose the abililty to slide between the high and low octane spark tables (i.e. this form of SD runs off the low octane table, so you copy the high to the low), unless you run a custom operating system.

In SD the AFR is determined by the OLFA and PE tables.

You can run OLSD or CLSD; in CLSD it uses narrowband to trim to 14.63 and will goto the OLFA/PE tables when the throttle is opened sufficiently to enter OL/PE.

One advantage is that you can dial in the exact AFR that you want (wideband AFR exactly equals commanded AFR).

Another advantage is that VE/OLFA/PE table lookup is pretty much instant, whereas MAF input has finite time lag.

Another advantage is that an over-oiled K+N air filter won't foul a non-existant MAF.

Of course the point to all this is, if you had tuning software you could tailor all of this to personal taste on a daily basis.

BTW: Look in the PCM tuning section to see more comments regarding running around MAF-less.

:cheers:

http://i2.photobucket.com/albums/y20...s/P1010004.jpg

http://i2.photobucket.com/albums/y20...s/P1010005.jpg

http://i2.photobucket.com/albums/y20...s/P1010007.jpg


http://i4.photobucket.com/albums/y14.../MAFOTRCAI.jpg

http://i4.photobucket.com/albums/y14...MAFOTRCAI2.jpg

http://i2.photobucket.com/albums/y20...parts/otr1.jpg

http://i2.photobucket.com/albums/y20...parts/otr2.jpg

I like the ORSSOM one a lot!

I plan on install a fast 90 down the road... (I have heard the Fast 90 is 1" longer than stock...)

I wonder if this will still fit after that?

http://i4.photobucket.com/albums/y14.../MAFOTRCAI.jpg

I took an SD tune into account for a span of time, then kept the larger MAF because it was what was on the car at the moment.

However, I hear that there are certain parameters that are more difficult to tune and other parameters that are better left to one form of tune or the other, not sure which would be most applicable to the situation, that a tuner can differentiate from the various methods, and best apply the strategy of the form of tune that is there.

I truly appologize for the lack of distinction but I have to say that looked :pimp:

Where did you get that idea?

Any change to the induction tract (from the cam all the way back to the air filter) "techinically" requires recalibration of both the VE and MAF tables. The PCM compensates for minor changes via fuel trims, ie Closed Loop.

From here: http://popularhotrodding.com/tech/0403phr_hemi/

For example, changing cam will change reversion/resonance in the intake tract which causes the MAF to "misread" so a new MAF table will be required (or MAF can be tossed).

nice cars

I have found at least with cams in the 230/230/110 range on stock LS1's, the MAF's works ok....its the O2 sensors that act retarded.

Ive got my open loop speed density tune dialed in pretty well, but my fueling is never as accurate as when im running my maf. I know mine's not a restriction since ive hogged it out an extra 40%. Youve got a bigger maf with the ls2. Id keep the MAF if at all possible, but thats just my opinion.

Given the opportunity, I would challenge him on this - and yes, I'm quite aware of his contributions to our hobby :D