Ported Stock MAF Ends and Tuning
Thread Starter
Joined: May 2005
Posts: 1,410
Likes: 11
From: Port St. Lucie, Fl
Ported Stock MAF Ends and Tuning I have had 3 LS1 Fbodys from 1999 to present, and on all of them I had ported descreened, cut middle center piece and smoothed the Stock MAF from installuniversity.com. All of these cars I took to the track and beat alot of cars on the road(Racing). I would like to say that when done correctly this is a good free mod. My current car was running lean when dynoed, but that was because of a front bad O2 sensor, car has 75,000 miles when fixed, car was back normal. Also took car to GM Dealer had a tech 2 on veh and all the peramiters were normal even the stock MAF that I had ported and modded. We went out for a test drive and no problems on tech 2.The tech 2 only saw the bad o2. So my point is that when this mod is done correctly you can probably pick up more horses may be 3-5. It just seems like so many people talk down against this mod where it has worked well for me and my other LS1 cars. I have a cam only car with a custom tune and an afr 12.8-13.1 with good O2 sensor's up to 6000 rpms. I believe the key for it to work well is to not to mess with those little wires inside the MAF. You have to be real careful not to break those little wires, just like installuniversity says.
Last edited by corvet786c; Sep 10, 2008 at 07:48 AM.
Main reason an un-tuned modified throttle body is not recommended upon is that porting & descreening is generally done without re-tuning the MAF table. Even though your scan may have been within a GM paramater, the fuel trims are correcting the lean condition that was caused by changing the throttle body. This has nothing to do with WOT (12.8-13.1). The problem is that if you've done enough to max out your STFT's (doesn't take much), then there is no short term trim remaining to correct a lean condition under normal driving conditions. This can be seen in freeway driving in 5th or 6th gear. The timing is higher @ the lower RPMS & while trying to accelerate, even a little bit, can cause engine knock, as a result of maxing out your STFT's that otherwise would have prevented the issue. There are other normal driving conditions effected, but, don't need to be mentioned in order to understand the problem.
So, the people whom advise you not to do it know what they're talking about. Not making a tuning change doesn't mean that you can't get away with not tuning, it means that you're using up your safety net. All intake related mod's need to be re-tuned & then lleft alone.
So, the people whom advise you not to do it know what they're talking about. Not making a tuning change doesn't mean that you can't get away with not tuning, it means that you're using up your safety net. All intake related mod's need to be re-tuned & then lleft alone.
Your thread is a classic example of how people live according to their own reality independant of evidence proving otherwise. As was explained above, any modification to the intake causes issue with the tune, whether or not you get away with it. Good-luck 
Any change to your intake be it the TB, MAF, intake tubing, or intake manifold is going to throw off your sensor calibrations. They are OEM tuned for the exact hardware you have. Yes, the car will try to adjust for those changes but it's not going to be correct until you recalibrate the sensors.
Thread Starter
Joined: May 2005
Posts: 1,410
Likes: 11
From: Port St. Lucie, Fl
Any change to your intake be it the TB, MAF, intake tubing, or intake manifold is going to throw off your sensor calibrations. They are OEM tuned for the exact hardware you have. Yes, the car will try to adjust for those changes but it's not going to be correct until you recalibrate the sensors.
Free Flowing.
