6.2 Stock Exhaust Details to modified True Duals with X Pipe

[rosepaule]

Hey guys, 
 

I want to change up my exhaust a bit and get some better performance. My plan is to cut the exhaust after each of the cats. Run 2 - 2.5 inch pipes from each cat to 2 flex pipes into an X pipe  then into 2 single in single out Flowmaster cans (Series 40, Super 44, or Super 40's... havent decided yet) then cut the second Y in the back and bring the 2 single pipes to the last bit of pipes that exit out the tips. Wont be a true dual with the X pipe in there.

 

Anyone know of any problems that I may run into? I did hear that someone did a muffler delete and removed 1 of the 2 flapper valves and his Auto Stop no longer functions.... interesting but I can see how they would use this to determine if the engine should shut off.

 

I'm going to dyno before and after to see results.

 

If anyone wants to know the details of the stock exhaust system they are below...

So from the cats, its 2.5 on the left bank, 2.25 or 2.5 on the right bank into a Y that goes to 3 inch into a flex pipe then into the muffler. Then 3 inch out to a Y then dual 2.5s out the back

[19AT4]

You won't have any issues with a true dual set up, but id recommend a few things.  It sounds like you're going for performance, I'd look into more of a free flowing muffler, the flowmaster one's are all chambered.  Carven makes awesome mufflers, the TR series would be about the same sound level as a Super 44 but 100% non-restrictive, other good one would be the Borla XR1 (Very deep with a moderate sound level)  When I end up doing true duals I'll be using 3" piping all the way as well.  2-2.5" sounds really raspy.  Curious on the before and after dyno results though!

[brendon444]

Clamped open both flappers on my 6.2. Did absolutely nothing for sound.

 

Might actually drill holes in my muffler to see if I can get a better sound for the time being. Will eventually change it so i don't care about wrecking the muffler. 

 

Do you know what the 2- small muffler looking things are right before the exhaust tips on the 6.2??? Are they wide open? 

 

Looked over the exhaust today really dont see any gains from running a cat back system as its 3.5" majority of the way and not much restriction other than the flappers and muffler. Just wondering about the budges right before the tips?

[OnTheReel]

@brendon444 They are resonators. I believe they are a straight through type design (most are) but not sure. Mine went to the scrap heap immediately.

 

You can get 90% of the catback gains (13hp GM claims) by getting rid of the flappers and the big ass stock muffler. The flappers don't look like much on the outside, but the mechanism inside restricts about a third of the pipe, even when clamped wide open. It’s really a shockingly bad design. They use 3.5” sewer pipe for an exhaust, like they should, but then neck it way down before and after the muffler with those flapper things...what’s the point?

Leaving the resonators wouldn’t be a bad idea. Unless the system and muffler is designed to not use them (like a cat back would be), you’ll probably have drone with just a muffler swap and no resonators.