I want to buy a downpipe for my 02 gtp, but i have lots of questions before i actually get it.
Should i get a 2.5" or 3"?
How hard is it to install, is their any directions anywhere i could follow?
How much would it cost to have done somewhere?
What would i need to install it?
What kind should i get? Will it fit everything else thats stock?
Answers to these questions, and maybe anything else i should know is greatly appreciated

http://www.grandprix.net/ubb/ultimatebb.php?ubb=get_topic;f=1;t=009463#000000

That only helps with a few of my questions. Maybe one of them

1. GTP=3"
2. You can buy a bolt in downpipe from ZZP, 4 bolts off and 4 back on and you're done
3. You would have to go somewhere and ask to find out
4. Sockets, ramps, and PB Blaster, maybe new gaskets
5. Yes

The larger the downpipe, the less resistance, the less the torque. The GTP's supercharger eliminates the issue of torque loss, yet gains from the free-flowing exhaust by reducing KR.

Short answer:
Boosted: 3"
N/A: 2.5"

Sockets, ramps, maybe new gaskets
does the zzp downpipe come with these?

Here's a write up: downpipe install You can order front & rear gaskets from ZZP, or from your local auto parts store: Front Gasket: 31605 (Walker)
Rear Gasket: 31532 (Walker)

No you kind of need to provide your own tools

You'd be better off having someone else do it because unless you have a cutting torch all the pb blaster in the world is not going to do it believe me i know. It doesn't cost much $100-150 tops.

It really isn't that easy unless you have no rust and have plenty of tools, including an impact gun and tons of extensions.

this all sounds like a u bend delete isa better, because its wayyyyy cheaper, easier, and still reduces kr and give 5 horsepower, where as the downpipe is 15?

If you wanna go further with your mods, you would be better off getting the DP, which includes the u-bend delete. I would get the ZZP DP: http://www.zzperformance.com/grand_prix/products1.php?id=551&catid=110

Most people who get u-bend deletes regret not just doing the whole DP. Maybe not right away, but if you plan on continuing modding, you will regret it.

I dont plan on doing too much more, atleast not for a good amount of time. I just purchased a brand new u bend delete w 02 sensor and gaskets for 35 bucks . Good deal

not really that good of a deal... you have to pay someone to install it too

My neighbor can do it all for me... free
Good deal.

Installing the U-bend delete is a waste of time and money,you probably have the original cat which will soon need replacing so why not go with a 3" stainless DP with a hi-flow cat and gain some real performance and avoid having to redo the job later if not sooner ,just my 2 cents.Chico(pops)

I have an 02 GTP and the down pipe was a great mod! I got exactly what Chico suggested. The 304 Stainless with interlock flew, and high flow cat. It has now been custom redone to hook up to my headers, but it was a great mod.

I dont have that kind of money. That would cost like 250 bucks. Im spending 35 instead.

We speak form experience. It'll end up costing you more than $35, most likely. And that cost could be best spent towards a downpipe.

Or you could hold off until that cat does fail and then it'll be much cheaper to swap the whole DP for an OEM cat.

we arent able to force you to do it, but we can speak from doing it before. Do whatever you want, but youre more than likely going to regret it.

You can lead a horse to water...

I'm glad I went with the whole down-pipe instead of the u-bend delete. I went with a Magnaflow MPE-23405 DP from Summit Racing for less than $150. It took me less than 2 hours of actual work. Of course, prep work began early in the morning. Here's my process:
1.Drive the car onto ramps. 2.Eat breakfast while exhaust cools completely. 3.Thoroughly douse bolts with rust penetrator & drape a soaked rag over bolts. 4.Kill a few hours to let the rust penetrator do it's thing). 5.Get to work.

You need a variety of extensions and one of those bendy u-joint socket thingys (someone please tell me what those are called) and a long socket wrench or breaker-bar (for maximum torque). My GP is a '98 living in New England and the rust penetrator worked well enough that the nuts came off easily and undamaged.

What he said!

Does anyone know where I can buy a dp with a high flow cat for cheap. I have a 97 gtp

ZZPerformance is where I JUST bought mine from. They were the best deal overall. Iirc, I didn't pay much more than $220.

U-joint adapter.

You're replying to a 3 year old post.

Herc=OWNED!

I don't look at the dates. I just read the threads.

LOL anyway, old bean! LOL

Speaking of "old bean", has anyone seen our Limey friend (GazUKv6)?