I just installed the Borla TD exhaust but it is a little quiter than what I thought it would be. If I add the Crawford cats, how much louder should I expect it to be and what type of gains are typical?
I chose Borla because I didn't want anything real loud, I just wish it was a little louder though.

Thanks

 

It will get a little bit louder and just a little bit lower in pitch with cats. Not a lot of either, though. When I had the Borla and Kintix cats, the car sounded excellent, but I had an annoying drone in the 2300-2800 RPM range, which is highway cruising speed. The car seems to put out more sound at that range of RPMs anyway--stock exhaust or not--at light to medium levels of throttle.
The cats will add more power...enough to feel anyway.

 

did u change exhausts or cats, since u r sayin u "had?"

 

Good eye! Yes, I installed the Borla and cats at the same time on an otherwise stock G35. I loved the power increase (mainly 3000 RPM and upward). But my wife and some clients didn't quite like the additional sound/noise, and I did have the exhaust drone in the RPM range where you're cruising on the highway. I took off the Borla and put the stock exhaust back on, and kept the cats. I wanted at least some performance increase.

The high flow cats with stock exhaust is barely louder than the with stock cats, so that's what I have for now, and I'll probably just keep it that way (re: the exhaust). The cats do add more power across the RPM range from what I can tell. Next mod will probably be a plenum.

 

I have the same setup. I thought it would be louder with the cats but didnt notice much difference. It wasnt until I put the kinetix plenum on that the car was much deeper in tone. I love that mod!

 

How about the power that the plenum produced? A noticeable difference?

 

A Plenum or an Intake like the Injen CAI or the JWT Popcharger will make a bigger difference in sound than the HF Cats. Put all of them in and you will get a really nice sound

 

I really didnt notice a differnce in power until I took the plenum off. Thats when I noticed how much power it was delivering. I took it off cuz I had to go to the dealer and didnt want any trouble.