Driver's side exhaust at the cat

**Rikitikitavi** · 04-26-2008, 01:30 PM

Has anybody replaced the factory flattened piece that is bolted to the cat with a ROUND section and did it help?

**kev70ss** · 04-26-2008, 02:52 PM

Are you talking about the y-pipe? If so SLP makes a replacement y-pipe that is round, but i dont think your going to gain a lot of power

**Rikitikitavi** · 04-26-2008, 03:15 PM

Thanks, not sure if it's called the y pipe but it is flattened. It is one of the arms connecting to a y. It looks as if it would help reduce restriction. I was planning on putting a cutout just past the y on the passenger side. Another option I saw somewhere is to place a cutout just before the entrance on the muffler. I found exhaust cutouts on Jegs but was unsure of the diameter. It looks like 3 1/2" past the Y.

**Firebirdjones** · 04-26-2008, 03:21 PM

I tried it and gained nothing. Car was otherwise pretty stock at the time.

Just a little bit of added info though,,,,the factory setup is on 2 1/4 inches,,,the SLP setup increases this to 2 1/2 inches. It's a pretty well made piece,,,just didn't yield anything at the track though.

**Rikitikitavi** · 04-26-2008, 03:41 PM

Thanks man. What about the pipe just past the y? is it 3 inces or 3 1/2 inches? I was going to buy a cut out from Jegs.

**Firebirdjones** · 04-26-2008, 03:46 PM

Originally Posted by Rikitikitavi

Thanks man. What about the pipe just past the y? is it 3 inces or 3 1/2 inches? I was going to buy a cut out from Jegs.

Probably 3 inch. I have seen some that actually measure 2 3/4 inch. If the car still has the stock system this may be the case. Most of your basic aftermarket catbacks are 3 inch,,,unless someone put a mufflex system on there,,,,in which case comes in 3 1/2 and 4 inch.

A quick way to check is a poor mans dial caliper. Take a crescent wrench if you have one large enough,,,open it to fit snug around the diameter of the pipe and then check the opening with a tape measure

**Rikitikitavi** · 04-26-2008, 03:57 PM

Thanks

**67CamaroRSSS** · 04-26-2008, 09:55 PM

Originally Posted by Rikitikitavi

It is one of the arms connecting to a y.

That's why it's called a "Y" pipe.

The "I" pipe, or "inline" pipe that connects the Y pipe to the transverse muffler is generally where you'd put a cutout if you are using a mostly stock exhaust system. Depending on year, it will add up to ~10 rwhp/15rwt when its open (at least it did to mine when I did it).

**fxgs** · 04-27-2008, 04:58 AM

Originally Posted by 67CamaroRSSS

That's why it's called a "Y" pipe.

The "I" pipe, or "inline" pipe that connects the Y pipe to the transverse muffler is generally where you'd put a cutout if you are using a mostly stock exhaust system. Depending on year, it will add up to ~10 rwhp/15rwt when its open (at least it did to mine when I did it).

When I had my SS dyno tuned, I picked up (only) 4 rwhp but 14 ft/lbs of rwtq with the cutout open.

**67CamaroRSSS** · 04-28-2008, 12:35 PM

Originally Posted by fxgs

When I had my SS dyno tuned, I picked up (only) 4 rwhp but 14 ft/lbs of rwtq with the cutout open.

I started with a stone stocker which dynoed at 306/323 at the wheels. Added a Volant CAI and a QTP 3" electric cutout. With the cutout open it dynoed ~313/338 so for me it was a good investment. I then added a set of QTP LT's with a custom 3" Y-pipe. I then laid down 343/357 with the cutout open but it was only a 2hp/4lb-ft gain over it being closed. I now have LT's & TD's. I haven't dynoed it this way but I did gain .05 sec and 2 mph in the 1/4 mile over the previous combo.