LOL, once you start you just can't stop!

That's not bad at all! I didn't know that. My friend with just about every bolt on (02 WS6) made 320rwhp but he doesn't have a tune and was running a bit lean.

 

320 is on the low side...mustang dyno? I dyno 335 before the tune and pick up around 17 with it.

 

Yeah, 320 is very low. I have seen 01/02 cars stock make 320-325rwhp

 

I don't think it was a mustang dyno. If it was, that would explain a lot.

 

Auto or manual. If it's a 6 speed he has issues.

I would start your friend off with headers, exhaust, underdrive pulley and a lid. I hit 360 rwhp with just that. See how your friends likes that, blow his doors off (lol), and he'll want to do more mods.

 

Ok. Lets look at this rationally.
1. He said he wants to keep the internals stock.
2. he doesnt want to spend to much and go "crazy"
3. people often get the mod bug and want more power, mo powah, mo powah!

So, lets cover the bases...

1. Start off with headers. These are a big pickup and probably what many would consider an essential bolt-on. He can go cheap with pace setters, or not so cheap with Kooks or ARH or what-have you.

2. full exhaust. Stock sucks, sounds shitty, etc. Figure out what tone\volume he wants, and go from there. go with true duals if you can.

3. get a lid. better intake flow will be nice, pick up some hp.

4. Ported Tb. He can send in his and get the core refund since he rarely drives it, it wont matter if it is down for a bit. This wil pick up HP and a snappy throttle response.

5. Get a tune. It is pretty neccesary to run properly with headers, ported tb, etc... and will be a power gain on its own.

That is fairly cost effective and the big bang for buck bolt ons without going to "far".

Now if he is happy, great. He should be content for a while. Now, if and when he gets "the bug" (not HIV) and wants to go faster, he is all setup for this.... a maggie.
Since he wants to keep it inexpensive, he can probably still find some 112's or 122's around for a good deal. There was a sponsor on here selling them very cheap a lil while ago. Or, he can just say F -it and go for the TVS 1900. I recommend the maggie for many reasons. It is reliable as all hell, hence the reason it is used as the OEM blower. It makes great power instantly, perfect for the street which is what he uses it for. It also keeps stock driving behavior, unlike some head\cam work. It also isnt much more expensive to buy a $5000 blower and install it himself with some friends over a week or so than it would cost to have head\cam work done somewhere. For the price difference, you will get way more power potential out of the maggie.
The maggie is also pretty quite, not making sound at idle like a centri, or nearly as complicated or expensive as a turbo setup, or as much upkeep.

Now from there, i would imagine he will be pretty satiated with the HP he has gained. If 550rwhp + is not enough for him at that point, he simply switches pullies for $70 or so and gaines 100-200 more hp or whatever.

At first, he will spend perhaps $2500 for the first mods (headers, ported TB, exhaust, lid, tune).
headers: $400-900
ported TB: what, $150 with core refund?
exhaust: $500
lid: $150
tune + install: $1500


He can also save money buying these parts used. I would highly recommend this as he can get great stuff barely used for great prices. So lets say this knocks off $500 or more.

He isnt into the car for too much. If he still needs more, he can do the blower and never worry about needing anything ever again. And if he decides he wants to return it to stock, sell it, etc... he can pull the blower right off and sell the car and the blower and get money back for his mods.