Hey guys first post on s2ki! Anyway, I have stock headers/cat with a 70mm dual Invidia Q300. Car is basically stock except exhaust.. Planning on getting testpipes to make her louder

 

What was the question? If you have 70mm exhaust go 70mm test pipe

 

yes.

 

You only need one and that will definitely do it.

 

You want to make a dual Invidia Q300 system louder? I needed hearing protection during the two weeks this horrible exhaust was installed in my car behind a high flow cat! You'll be louder than that and the system will stink (smell bad) as well.

-- Chuck

 

Q300 sounds like crap with a test pipe. It will make it louder though if that is your only goal.

 

Q300 with a TP is ear shattering when you get on it...and has a lot of buzz/ping when you're shifting normally. IIRC, it was quiet with a stock cat on my friend's car.

However....when he floored it in front of me with a TP, I had to look around because I couldn't figure out where all the sound was coming from. I thought there were multiple cars flooring it at once. I was enveloped in noise.