Hey Audiforums, I pulled my cat out to make room for a test pipe awhile back and now I'm kinda thinking what I pulled out was actually a techtonics high flow!
Can someone confirm this for me, or at least confirm mine isn't stock? Also, what kind of performance gains are to be had with a test pipe vs a high flow? My girlfriend is ALWAYS complaining about the smell, and I'm a little nervous about the smog test.

Here's a pic of what I'm assuming is stock next to a test pipe:


and here's what I pulled out next to my currently installed TP:

 

Put your girlfriend in the trunk next time she complains about the smell.

That's all I have to contribute sorry.

 

Edit: Double post.

 

hahah well dude.. the bottom pic definatley looks like a HFC.. i think i read on another thread when you were asking someone confirmed that it was a Techtonics HFC but.. it looks it.. and i know i just pulled my stock OEM cat out in place of a test pipe, and my VMR test pipe looks exactly like the top pipe in the first picture.. the cat in my car looked nothing like any of those in those pictures you posted.. the chamber was more like square almost? it was the biggest hunk of rusty **** ive ever seen haha..

this is my test pipe.. doesnt it look like that first pipe in the top picture? i can tell its not exactly the same but.. pretty similar.. where is that top pic from?

http://www.audizine.com/forum/showthread.php?t=262259

 

Well on these engines I don't know for sure but physics is physics. Back in my Z days I saw a test done on a series of stage 3 and stage 4 twin turbo cars (13.5 psi, 400-420hp). Using HFCs from Random Technology vs test pipes, the average difference per car was roughly one hp. I imagine you'd see some such similarity on a 1.8T.

 

yea id def say they run pretty much the same.. prolly will save more smell and smog with the HFC i believe.. but i love my test pipe.. really doesnt smell too bad to me.. maybe thats cause im not behind myself when driving.. plus i really dont beat my car too bad to get it smelliing haha..

 

I dont mind it much either, but when I open the sunroof I can start to smell it. Its like it gets caught in my slipstream.
Either way, the exhaust shop wont fab me up an exhaust with a test pipe in, so back in goes the high flow!

Another quick reference: I plan on going no larger than KO4 on my car. Basic mods, 200-250 horses. What size exhaust for good performance and good sound? 2.25," 2.5" or 2.75"? I dont mind it being a bit noisy, I just dont want drone! But if it stands up and barks thats aight with me.
(Just so you all know, my plan is High flow to 2.5" straight through to the Magnaflow 14816, non resonated)

 

your exhaust shop must be a dick. take it to a mom and pop hot rod shop. they'll do a good job and for cheap. i agree with your exhaust plan. it's what i'd run at least lol

 

back when i had my bronco i took it to a wheel/tire joint that shall remain nameless and tried to put taller tires on it. They wouldn't put anything bigger than whatever it came with from the factory while the wheels were on the car so i had to take it home, put it on jack stands and take all 5 wheels back in my dad's pickup. chain shops do crap like that all the time

Kayak, i think 2.5 sounds like a good number, though sans resonator i'd be worried about drone at highway speeds

 

kayak.. i run 2.25" and it is plenty loud enough.. its 2.5" test pipe to 2.5" downpipe to 2.25" rest of the way back.. with a mid resonator.. 2.5" exhaust will give you a little better flow and is prolly a little more suitable for K04 even though K04 would be fine on mine.. but the 2.5" will gargle a little more off the gas when youre rolling, but i highly suggest putting in that resonator to keep away from the drone.. my car on the highway doesnt drone but with the test pipe its def louder.. without the resonator im sure it would drone.. keep us updated on your thoughts tho! we wanna know what you decide on