Right now the only missing link in my exhaust on my VIII is a test pipe. After seeing the gains that people have made from getting rid of the cat, I'm really considering it before my reflash. However, when I bought this car I told myself I wouldn't modify it in anyway that was going to get me tickets, because that was the problem with all my other vehicles.

My question is, being that I already have aftermarket 02 housing/dp/catback, would a test pipe make it marginally louder?

 

it will make it louder for sure especially if you have the stock cat in now. you can always weld in a resonator to quiet it down a bit.

 

If you are worried about sound just get a good quality HFC, it won't restrict you that much and on stock turbo you will make power with it.

 

I noticed that it is louder at idle, but only a little louder at WOT.

 

get the milspec 100 cat..it flows almost like a test pipe and it keeps the car legal

 

honestly, i threw a testpipe on and as posted above, the only time it was really louder was @ idle and a little deeper @ WOT.

 

I noticed almost no difference in noise from a testpipe to perrin HFC. It could be due to my greddy SP2 exhaust which is pretty quiet to begin with.

 

^ Greddy Catbacks are usually pretty quiet unless its the full Ti one... but i noticed a huge difference when i went from cat to no cat... esp @ WOT like other people have said... It does attract alot of attention from PO PO and its illegal for the street... but go for it anyway

 

Mil-Spec 100 Cat On my custom 3" Carbon/Ti set-up no test made it WAY louder under WOT.

 

Just get a TBE from someone like Greddy....its loud all the time. Problem solved. LOL.

 

Yes it is

 

I don't really care about it being loud under WOT, I'm not going to be banging through gears if I'm riding next to a cop, I'm kind of more concerned about how much louder it will sound during normal driving.

 

Cobb exhaust with testpipe and dp. Before I had the testpipe on, I had no problems driving long distances. After the testpipe, now its a bit irratating on long drives. No problems daily driving, just the constant I wanna call it mild droning becomes irratating after a while on the freeway.

 

With a test pipe your EVO will sound a little louder in normal driving, but it will definitely be louder at WOT. The test pipe is one of the best ROI mods for the EVO; best gain per dollars spent.

BEST VALUE MODS
1. Test pipe
2. MBC
3. IX/JDM DV (assuming your OEM DV leaks)
4. E85 tune (including Walbro and injectors)

 

Have all of those things except the test pipe obviously, and E85 is not an option for me because there is nowhere to get it around here.