xToPPxDoGGx

hey im gonna buy an 03 GT and i wanna start planning things out for it. My ulitmate goal is to S/C it, i was wondering if anybody can give me some info on the 4.6 motor , like how much horespower the motor can handle and some other usefull info on it , and some good upgrades to do to it thanks

Mr Graystang

I would not go over 400 hp with out being cautious , some say less some say go more. You wont have to worry about that unless you add some type of Power adder tho , when you start dipping into that then I would build your bottom end. IMO the 4.6 is one reliable engine and makes decent power for being so puny , some will disagree *cough LSx Nuttswingers *Cough. Skip all the BS mods and Add gears , a STS and TB/Plenum , Them made me feel like I had a brand new car , As for the Gains I making 230 to the wheels (EVI dyno Days FTW !). Dont pay for a dyno unless you go with major mods like cams , heads or Power adders. Just for starters .................

xToPPxDoGGx

ok thanks this info helps, as for the forced induction i really want a kenne bell and i dont mind taking the time to build the motor im not in a hurry, i want a 400 or 500 HP street car just enough to tear up some GTO's and Trans ams and camaro's

teej281

just put the supercharger on and dont go over 400rwhp and you'll be fine and you'll be tearing up them bowties in no time.

98redstang

First of all what kind of budget are you on? With a great tune you can go 400rwhp maybe even a little more than you have to start looking into forged internals. If your willing to build the engine first i would just do that so you dont have to pull it apart down the road like im gonna have to do soon haha.

Drivetrain wise gears should be a first and since you going blown i would say 3.55s or 3.73s and a nice short throw.

Suspension/tires i would get sfcs, lcas and either slicks or Dr's cause your street tires are not even an option with gears and 400+rwhp.

Exhaust i would go with lt's and a midpipe and catback of your choice. Loud = o/r or catted x + slp lms/magnapacks. More a of a old school muscle = o/r or catted h + flows. Those just tend to be the most popular setups but theres other ones out there your best bet is to listen to sound clips on youtube and see what you like. They all add pretty much the same hp.

Without knowing your budget i can really tell ya too much more cause theres so many other things you can do depending on how much monies you have. You could get: blower cams, 31 spine rear, ported heads, intake it all depends on how much your willing to spend.

Welcome to the GT club!

teej281

Blower and gears first, the rest of the stuff later. Most people do the little stuff first but what should be done is the big stuff, then when you get to that point, start adding little stuff until you are happy with it.