hahns bangs on the torsion beam like a sob...sounds horrible when it hits. imo you shouldnt have to fix a pnp part :/

 

the AP has better flow and no crimping unlike the stock exhaust even though they are similar diameter

 

do u think its about backpressure, cuz its not.

there are plenty of 300+whp LNF's with the stock exhaust. the AP will flow better than stock. i agree on how you say for the future tho a 3" is best. but for now since hes prolly gunna be on the stock turbo for a while a 2.5 will suffice.

 

if turbo cars didnt need backpressure then lets just put 4" or 5" exhaust on our cars. and your right the hahn bangs on the torsion beam for lowered cars.

 

um..I would say no exhaust then. Because you should go do your research

 

list them

anyone well most anyone that does bolt ons and tunes for 300+ will 99% of the time have an aftermarket 3" exhaust.

I think the stock crimps down to below 2.5" a few places so I would concur with that statement.

 

Agency power sells them for $400 on their website

 

I'm pretty sure I'm ordering mpx since I'm lowered and it's proven not to clunk on lowered balts. i haven't heard much about the agency power but i do like the price.

btw i'm zzp catless already so i'm hoping the mpx will sound pretty beast because i kind of sound like a lawnmower right now with the stock catback.

 

im going to leave off with this, both mpx and AP are probably the most liked catbacks out so far for the tc. both are of high quality and you wont be dissapointed with either. hahn on the other hand is too quiet and bangs around. now with the whole 2.5" debate. AP knew what they were doing when they designed the exhaust. from my reading turbo cars do like less backpressure then non, but its not only about BP. velocity plays the biggest part. now your engine size, turbo size, boost, hp, etc. are all taken into consideration. alot of cars with small turbos run only 2.5" exhausts, i no ko3/4 gti guys do this. if you plan on anything more then a bolt ons and a mild tune for your tc then go ahead with the 3". the 2.5" will help keep some low end and the velocity of it helps our turbos spool a little better.

 

well.... DAMN...! now I'm stuck with a decision just like the OP. I wanted the Agency Power originally. Here are my mods AEM CAI (revised), 3" ZZP Catless DP, ZZP Intercooler, Injen CP, Forge BPV, HPTuned on top of GMS1 pushing 25-26 psi with 0 knock, 38-40lbs airflow on the stock turbo, and OTTP Stage 1 Trans Mount. Still to come CM lowering springs and later OTTP Street Sway Bar.

http://www.youtube.com/watch?v=pwQoF...eature=related

 

How does an exhaust AFTER the turbo help back pressure if the turbo is making the back pressure on the engine? Also its very possible AP just copied the stock size like borla did. Unless they tell me they did research thats my thinking.

 

I ended up getting the agency power simply because i can get it shipped for 80 dollars cheaper. $422 shipped is the best i could find. Trust me this decision tore me up inside going back and forth between the two but ultimately lowest cost made this decision.

 

Mark my words...Ark's will be $900+...but it will probably be sexy with a blue tip on the end

 

Borla does massive testing on their products before manufacturing. They are one of the most well equipped companies when it comes to testing equipment and quality control.

 

and you have seen or have the results of 2.5" vs 3"?

 

not sure where in my post I implied I did.

 

So you are assuming 2.5" is the best? Or just saying borla tests their products?

The problem I have is, CSS is full of ****. People just tote their opinion as facts yet theres no proof to their statements. If you can prove Borla did do testing then we have something to talk about. Not trying to be a jackass, but I'm getting so sick of statements like this where opinions are taken as facts with no actual tests or results done.

 

^ Truth

Some people come up with the most illogical **** and post it as truth on here. Like Seafoam lmao

 

All i said was borla does extensive testing (which is truth) and your flying off the handle. Sit down and breathe for a minute man. I mean really if your so pressed about finding out the specific #'s for the amateure bolt-on modding market, write an email to the companies and draw your own conclusion. I made no such claim in my post other than Borla does extensive testing. Which they have stated on their website, press releases, and sponsored statements.

 

Forums are ideas, not facts, everything varies on opinions and results. I totally agree with you.

 

I wasn't going off on you, I asked you if you were stating a fact or what. I was ranting about CSS in general. People still cant explain why they think 2.5 is so much better than 3, because if anyone that said that did research they may have a different opinion......

 

Ya I'm totally cool with 2.5" exhausts. They arent bad. But when peoples opinions fly off as facts it becomes annoying, as every noob on here will remember those and tell 5 friends, then those friends tell 5 more and soon we have 90% of css saying it. Ricer math doesn't fly in real life. So if you buy the 2.5" because its cheap, I totally understand. haha exhaust are hell of expensive. It will flow better than stock, there shouldn't be an issue. As long as people know the physics and reality behind it and not pretending they know what they are talking about but asking for help or stating they don't know we are all good. I don't know every thing, but I have a handful of turbo and tuning books and read a lot, ask questions so I have a general idea of what I'm talking about and how things work.

 

i personally think a 3" DP is enough, and a 2.5" catback after that. after the downpipe the gasses cool and need less room. a k04 really doesnt flow a crapload of air to NEED a 3" exhaust. most people just think 3" is better because bigger has to be better right? not really the case. the goal is to provide the most flow, not have the biggest exhaust.

there is nothing wrong with having a 3" exhaust either, but your really not doing anything better or worse unless you swap your turbo.

 

we shouldnt even have exhausts if you want the most flow

 

yeah, that's what I'm thinking is going with a 2.5" from AGP because I don't plan on turbo swapping in the furture with the list of mods I have.