2 questions
 

1. What air filter is everyone running, and how do you like it?


2. How much do downpipes really help? About how many HP are you going to gain and what are some good ones?

guess that was more than 2 questions...

Myself and I know at least one other person run Spectre Hi-Flow PowerAdder Cone Air Filters With a Modular Air Intake tube (also by Spectre). I gained (dyno tested) 12HP off that. As far as the 3" downpipe I have not dynotested it but I noticed a substantial gain (huge gain for turbo models) in HP. Good Luck!

The downpipe will add quite a bit of power. It does this by increasing flow, And allowing more boost out of the the turbo because there is less pressure on the other side of it. Get a 3" dp, 3" hi flow cat or test pipe, and a good 3" exhaust, And youll boost high enough to hit fuel cut. Also about 280-290 hp. not a bad 1000 ish investment for 50-60 hp. I also have an ebay air filter adapter, with a K&N filter on it. Never got to test stock. You will also see a nice gain from 2.5" intercooler hardpipes. You can get cheap DIY kits on ebay for 80$, Or the 300$ cooleze kit. The stock IC piping is terrible tho. lol.

My car isn't a turbo. I have a cat-back 3" Blitz Nur spec system already so I was wondering how much would a downpipe help to my application. Also what about headers? i noticed that the stock manifold has pretty good flow already.

*sigh* you can get the adapter at pepboys for 5.99 USD. It is in the same place as all the modular air inatke stuff. So you don't have to wait and it isn't as expensive.

I already have a intake...

H8 you asked what filter we used. The mod adapter is part of that. Sorry alot of us answer the question and add info as the answers are for everyone. We get alot of people here :-)

Oh ok gotcha :) Ya I have the adapter and am currently running a tenzo R filter but its old. It was on the car when i got it.

downpipe
 

downpipes are for turbo models only.

Well dont I feel like a retard.....

I am not used to dealing with cars that mostly come in turbo. I had a eclipse and it was kinda the same situation but I never moddded it. Otherwise I have always been into muscle.