Whoever has a custom made exhaust...

[RicciDSM]

1997 TSi FWD is the car. Wanting an exhaust very badly but I dont wanna waste money on an ebay catback that might not even fit... I have a 2.5" Apexi DP just sitting here that could be put to good use. So I was thinking about buying a universal 2.5"in N1 Muffler off ebay real cheap, and then taking it to an exhaust shop to have a custom 2.5" exhaust made.

Whoever had this done, about how much did it run you? I know it varies from shop to shop but I just wanna get a rough estimate. Also how would this perform? Should be the same as an exhaust off ebay basically am I right? My final question is, do I need a tune? My car currently is running a full Intake, and next week Ill have UICP/BOV. Will I NEED a tune after my exhaust or should I be fine for a while?

THANKS!

 

[Zdrummer15]

A cat-back will net you nothing but sound unless you free up the rest of your exhaust. Remember air comes out of your turbo first, restrictions on that end are what keep your horses back. Until you free that up, the cat-back is overkill. If you want sound, just weld in a muffler. That's the cheapest way to get a good sound. If you want to do it right and get both sound AND power, start from the beginning. Overall mitsubishi makes fairly nice OE exhausts, they're sizeable for stock applications compared to companies like Honda which makes them too small and American which start with too big. However there are 2 huge restrictors on the stock DSM exhaust: the o2 housing and the cat. The stock o2 housing is tini... do yourself a favor and get a bigger one that actually lets the turbo do its thing. A manifold helps with that greatly as well. From there, match the size to the o2 and get a turboback. Catless will obviously net you more but that's not legal so depending on your application an HFC will help too.

Custom will cost much less then name brand. Cat-backs alone run 700$ give or take, you could make a custom turboback yourself for half that, or have a complete turboback made for similar. In the OP's case, I'd recommend an HFC and a custom cat-back. You don't want the bottleneck of the stock cat, it nullifies all after it and adds a ton of back pressure aka spool killing nightmare.

As for the tuning, will you need it after just a cat-back? No. Will you need it after doing an o2 and back? Well that's up to you. Its a great idea to get it done, 15hp and quicker spool from just your exhaust becomes 35hp or more with awesome spool from a tune depending on other mods.

I don't agree with this. Freeing up exhaust flow right after the turbo only to force all that gas back into restrictive stock piping is pointless. Yes a cat-back won't do much, but neither will replacing just the o2 housing. Start with the cat-back if you're short on cash, and get a downpipe as soon as possible afterwards. The downpipe and cat-back together will make a difference. As far as the o2 housing goes, in the near future just porting your stock one will be sufficient. In the future, I would recommend looking into PR's housings. They are about the cheapest I've seen and they make great products.