Aixtreme89

I have a stock 2003 GT with a K&N replacement filter, and flowmaster cat-back exhaust.

I am thinking about getting this package ( http://rpmoutlet.com/musv8cnl.htm )with the TRUEFLOW Inlet Pipe, 85mm Mass Air Kit, Cold-Air System. Do I need to recalibrate the computer with a diablo predator tuner or a similar unit. I see its just the housing so I take the stock mass air flow sensor and drop it into the new one, Right? So I would think I wouldn't have to recalibrate anything. I'm nbot sure, but if anyone knows for sure please let me know.

I am also going to buy a C&L intake plenum with BBK 75mm throttle body. http://rpmoutlet.com/newv8cm.htm

Aixtreme89

I guess this would be a better package. http://rpmoutlet.com/newv8ma.htm

The Great Cornholio

The C&L 85mm MAF housing will probably make you run lean, but a tune will correct that situation if so.

ghoste

There is certain tubes you buy for calibrating the MAF.

80mm Unit for 1999-2001 4.6L Mustangs
Stock Injectors (GT & Cobra) Black Tube (105)

Im not sure about the 2003 GT, call C&L and ask

C&L Performance
207G Green Cove Rd.
Huntsville, AL 35803
Phone: (256) 882-6813
Fax: (256) 882-2508
Open M-F 10am-5pm

04BlueGT

They advertise that no tune is necessary, but I'm not sure. The C&L maf is 85mm, but so is the stock maf. The C&L flows a 'little' better because of where the sampling tube is located, but it's minor. The filter is the biggests change here. After installation, find out your a/f mixture and see if you need to make any changes.

BTW, if you're using premium fuel (91-93) you should have no problems.

2000GT4.6

Honestly, if you can do it yourself you could get a set of LTs and a o/r X for not MUCH more money (200-300 bucks) and you will see much bigger gains. I am not sure that my intake bolton swap really did a whole heck of a lot. I installed everything (filter, MAF, inlet pipe, T/B, and upper plenum) all at the same time, and it was hard to tell the difference.

I did get the car dynoed after I got all of the boltons on though, and it was running pretty rich. I am unsure if it was the intake boltons, or if it was the exaust.

BTW, a diablo tuner etc, unless it has a tune specifically for your setup, won't help much. they won't know what to do with the car ( aka add or take away fuel). I am not a fan of the handhelds without some sort of way to check the A/F ratios before and after. I tried to get a tune kinda that way from diablo (told em my mods, and then they sent me a program) and it ended being WAY lean. Like dangerously so.