I had a catless DP on, so it's makes less sound. I do think it runs better in the low and mid range. I do not think it makes much difference on the top. Did you find a piece of pipe?

 

No I was thinking doing what you did with hole saw think I have one in the garage somewhere.im complete stock so might sound better,only thing I have is a tune,I like free mods though.

 

Are you going to get that nice increase in sound that you get with a 3" dp? With this core setup?

 

No, sound is very close to stock

 

Good morning,

I have read the modifications and testing on the cats on the HHR SS and I must say that I am impressed with 2005HHRauto's persistence in the pursuit of power and performance. I am not clear on this one modification. After I core the second cat should I tack weld a piece of pipe in the cat.

Thanks for your help
Wayne

 

Hey Wayne,
You may want to send a PM to 2005HHRauto and get his experienced opinion. I don't think he cruises this forum on a regular basis and he may miss your post.

 

Hi Wayne,
No pipe needed , after "coring", as the remaining cat-guts are quite
strong, & will stay in place...

 

Thanks for your help. I think that the wealth of hands on experience that you bring to this forum has helped many owners of this little unappreciated hot rod or as my daughter calls it (Hip Hop Ride)

 

Thanks for your reply. I did try to send him a message through this forum but his mail box is full.

 

i would think you want that "core" hole bigger than that small hole saw can do though.....