Stock Midpipe (3rd Cat) Question

So I'm protuned and I'm running a racepipe (catless), but I'm thinking about slapping my 3rd cat back onto the car. I was protuned with the race pipe, so I was wondering if I'm going to lose much performance by putting the 3rd cat back on? First I have to replace the bolt we snapped yesterday :naughty: .

Thanks!

Craig

 

i think it does make a difference..
reason if u disturb the way u got ur protune it will disturb the whole thing..
in this case u had stock air box and got protuned then wanna get a CAI u gotta get protuned all over again.. simple..

 

That's what I figured. I may just go to a muffler shop tomorrow and see if they can cut out the 3rd cat and weld in a regular pipe in its place (that way I can put the heat shield back over it). I think that should have the same flow as the racepipe, and thus I shouldn't have any performance loss.

Craig

 

there is a race-pipe (prodrive, I believe) that will allow you to bolt the cat heat shield on to the race-pipe so that it looks like you've got the cat there. May want to check into that. Maybe find a pic of it and have someone weld a couple of tabs on the pipe you've got now.

 

I think they run for about 125 to 150.

I went to a muffler shop and gota general quote of around $300.00 to weld a flex joint on a catback. :eek3:

 

since you live here in ga i wouldn't think it would be a problem with inspections. "Grand muffler" will make you something (they made my whole exhaust) if you drop by. Fairly cheap too. Check em out.

 

Yes you will lose power. Less diameter on the stock midpipe than race pipe most likely, also more restricted flow.

 

better to get tuned again

 

He may loose some hp but is one cat really going to influence his tune that much?

 

I believe (unless I am mistaken) that the stock midpipe is 3" tapering down to 2.5" (just like the race pipe I installed).

I figure I'll just leave my racepipe on the car for now. The main problem is I have this tin can like noise coming from my exhaust at WOT in 1st and 2nd, and I think it might have something to do with the connection between the donut flange. I can't use the spring bolts because the threading isn't long enough to connect the two flanges of the pipes together. Maybe I can try and have the stock flange removed from the pipe and welded onto the racepipe.

Craig