Hey guys ive been looking through some old threads and getting some mixed info here. Being my car is 90% street/grudge car i want to attract as least amount of attention as possible. Will running longtubes, 3'' Ory and a 3' E-cutout be sufficient with a stock catback? The goal is to keep the car quiet as possible until race time, then open the cutout for racing. Will the stock catback be TOO restricting when not having the cutout open? thanks for your replies.

 

I have the same setup on my car for years because I never decided on which catback. It is pretty quiet but a little raspy and restrictive. I do open the cut-out at the track and its a 2 tenths difference, that's how restrictive the factory muffler is. But one thing I like is the stock tailpipe sleeper look.

 

My next car ill be running the stock cat back with a cut out. My car with my current setup is just insanely loud and not everyone likes the volume.

 

I'm running a hooker header, TSP y pipe and stock cat back. Just went 12.39 / 108 last week. It is a little louder than manifolds, but I like it.

 

OP, I have the setup you are describing and think DadsZ28 has it right. Once you go long tubes and remove the cats it does not matter what catback you have it is going to be louder. With that said, the factory catback is going to be as quite as it is going to get IMO.

 

Which tsp y pipe do you have ory or catted? How does it fit?

 

Just get the Magnaflow catback. It's barely louder than stock but sounds way better and flows even better.

 

^what he said OR an SLP Dual Dual if you can find one. Both flow a lot better than stock and both are just as quiet as stock if not just a tad bit louder.

 

ive got longtubes, catted Y, and hooker aerochamber catback here with stock tips. It is very quiet at idle.

 

I'm riding on LTs, ORY and stock SLP Dual/Dual, definitely a sleeper until WOT. I'm eventually going to add a e-cutout.

 

LT, catted TSP Y, and Magnaflow 12267 muffler. It is quiet when I want it to be, but can get loud when I want it to also. It is a sleeper setup for me.

 

How do you like the tsp catted y pipe? Any issues with the install?

 

It was a TSP catted Y pipe I picked up cheap off craigslist. It fits okay but I am also dealing with pipe that was already somewhat compressed together. I didn't expand the ends and put it together like the guy before me had. I think it could be a little higher if I wanted to play around with it. There is no way to hang the y pipe like I have seen other brands. Maybe this is an older pipe but there is a lot of weight hanging between the headers and muffler so I have to improvise.

Sorry, can't really advise yes or no because it is a used piece and I don't know the age.

 

IMO, once you've added H/C to the mix I'd upgrade the y-merger to at least a 3.5"exit up through the cut-out then reduce it back down to 3" to mate back up with the factory exhaust. This way you still have max flow(with cut-out open) regardless of how restrictive the rear section of your exhaust is.

 

It's very easy to install. The merge may leave a lot to be desired, but overall I am very happy with it as far as fitment and clearance.

 

Thanx guys!

 

It seems silly that most Y's merge two 3" pipes into one the same size and then reduces down even further to about 2.75" but as we know that allows it to connect to the stock catback. As the power increases you will need something larger in diameter running out the back (or to a cutout).

To give you an idea: I have minimal mods so with my ported stock TB, LS6 intake, Kooks long tube, Y setup (removed the reduction to 2.75"), and stock GM Performance catback I saw about a 11hp/8tq gain with the 3" cutout open. In this case, an aftermarket catback will only see minimal gains IMO.