I have an RB turboback, and after a long *** fiasco that involved the police I ended up taking my car out of one shop and brought it to another place to bend me some pipes for my intake to the new turbo, so I was going to have them put in my exhaust while they were at it. I have a full RB turboback, and he's like "if i'm taking out two cats, I have to put at least one back in" and he's being really strict about not being involved with illegal emissions. Problem is, I cant really drive the car out of there since i'm in VA and the car is in NJ with stock injectors that I dont want anyone driving on. I cant exactly go back and bolt on the exhaust by myself until like thanksgiving, and I doubt they will keep the car for that long. So what i'm wondering is could a Bonez high flow cat be used in replacement of the RB presilencer with minor fitting adjustments, I mean its at an exhaust shop, so if anyone can make it fit its them. Also, if it CAN fit, how much of a performance decrease will I see?

 

You shouldnt see any noticable performance decrease between a good high-flow cat such as the Bonez , and a midpipe. Do a search in the 3rd gen forum, there was a very lengthy thread about that a while back. People did back to back dyno runs , and also 1/4 testing, and results were about the same between a high-flow cat and a midpipe. I have a Bonez High-flow cat that was used on my 88 Turbo2, bolted directly from the RB downpipe to the cat-back. If you would be interested, Im selling it for about 1/2 what youd pay new from Rx7.com. Check out my post in the F/S section.

 

which one is louder ?

 

Midpipe is definately louder...

 

Well its a presilencer not really just a pipe.