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I have a stock '07 GT and ~$1000 for performance upgrades. What's first and why?

handen

New member
As the title says, I have a bone-stock '07 Grand Prix GT and I want to drop some cash into the engine. I don't want to get too crazy, but I would like to be able to surprise someone with a GXP or any of those newer ~300hp V6 Challengers and Camaros. I've already had a surprisingly evenly matched run-in with a sort-of-hotrodded (i.e., loud and obnoxious) GXP around town, so I imagine it's not completely out of the question to skew the performance advantage slightly in my favour, no? I've already got my dad's 2009 3.5L V6 Challenger beat without even having to do anything but I'd still like to be able to give my buddy with his 2010 300hp V6 Camaro a friendly run for his money.

I'm trying to plan how to get the most out of this car in roughly $1000 increments. Right now I'm only planning for the first increment. I already have a TransGo shift kit, I just need to have it installed, so discount that from the $1000 for now (it was only like $50 anyway.) Once that's taken care of, I've decided on the Overkill ASI Series III kit with the larger MAF sensor ($195) with pulley mods in mind for down the line, as well as the Overkill PCM ($225). So far that's ~$420. I'll also be throwing a train horn in there for cheap laughs but that's beside the point right now.

Now, with ~$580 remaining, what are the next most beneficial performance upgrades to consider? Headers? Cams? Modular pulley? Intercooler? Catback? Cat delete? 3" downpipe? Performance mufflers? Performance exhaust tips? (Kidding...) Throttle body? (Are there any throttlebody upgrades for the 04+ Series III GP's? It was one of the first things I looked for but I could only find Series II upgrades...) Should I wait until I can spend a little more on something a little outside of my budget range? (I.e., that $3000 turbo kit from 3800performance? LOL!)

I've read the 3800 tech FAQ on the Overkill website, but honestly most of it goes right over my head. It looks like header and cam upgrades would be the way to go eventually, but I'm completely clueless when it comes to valvetrain stuff (I'm also under the assumption that valvetrain stuff is both labour and time intensive and therefor expensive as hell and probably out of my realistic budget reach, but I'd be glad if someone could show me otherwise), so for the time being I'm more focused on pulley and air intake/exhaust mods because I can wrap my head around how that stuff works. Any good places online to learn about valvetrain mechanics, especially as relating to the 3800 engine?

Next, what smaller things should I also be taking into account sooner than later? 180º tstat? Autolite 104s? Other?

I've been researching the forums and comparing opinions and reviews but right now it's all a little much for me, so rather than jump into this on my own and end up possibly disappointed or hoodwinked because I've never done anything quite like this before, I'm here asking for guidance. I know generally what I want done, but not exactly how to do it, or what order to do it in. Keep in mind that I'm not really well versed in the technical aspects of car mechanics... I got into an accident at 16 that made insurance prohibitively expensive for most of my adult life, so rather than spending my teenage years driving around, learning about cars, and dumping all of my money into car stuff, I got into playing and modifying electric guitars. It's this "mod factor" that I draw parallels between my guitar habit and what I know is possible with my car thanks to forums like this, I just don't really know where to go past the regular cold air intake and pulley stuff that everybody seems to start with.

Apologies if this is posted in the wrong forum or if I'm asking too broad of a question here. I'll gladly post this in a more appropriate forum if necessary. Thanks.
 
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I'm guessing you've already read the safely modding thread, (I sincerely hope) and trust me, this is the perfect forum for that kind of question...

You will need a way to scan for KR, before anything else... Keeping Uncle Chip away is your first priority. Headers, colder plugs, a good tune, and a pulley drop is your next step, then you can work your way up.

There's plenty of people on here that have the advice you're looking for. The only thing you might have a problem with is the tune, Overkill seems to be the only one that can tune 06+, and you'll need an in-car tune for the bigger mods.
 
Skip the MAF upgrade, you won't outflow it with minimal mods and only a pulley drop. Save your money there.

Headers or a plog/downpipe combo for exhaust. The cheaper headers don't come with a cat converter if you have emissions.

Start with a 3.6 pulley because GEN V's are better than the older GEN 3 superchargers, a 3.6 is like a 3.4 on a GEN 3.

There are no TB upgrades for 04+.

As said above, you'll want a scangauge and overkill seems to be only person selling tunes for 06-07.
 
fenderwell or other "cold" air intake. Headers or Plog like said above. The thermostat when you get the tune, the 104s are good. 3.6 pulley is fine. It looks like you are having someone else do the work based on your Transgo shift kit comment so stick with the basics because install gets expensive with a lot of this stuff. If you are doing it yourself the money goes a lot further. Rockers are cheaper to install vs a cam.
 
As for the MAF upgrade, my reason for thinking of going with that is because Overkill's cold air intake system comes with it by default and it's still about $100 cheaper than the comparable K&N intake. When in Rome, y'know?
 
Build your own intake system. There is no performance gain to be had from a "cold air intake" system.

The supercharger will take any "cool" air that it takes in and superheats it anyway. As long as the air coming into the motor is within 10-15º of amibient, you are just fine and that's why most of us just save our money and build a intake for less than $50 bucks.
 


A lot of people (myself included) have upgraded rockers on a stock cam with good results. Much much easier to install.
 
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