I would like to first start off by saying its been a while since I have posted on here. I havent posted since I had my old truck back in 09. I sold that and now I have a white crew cab 6.2L 4X4. My question is I am going to get a custom exhaust done on my silverado. I will be ordering PaceSetter 72C2267 Long Tube Header with Armor Coat for 2/4WD 4.8L, 6.0L, 6.2L Chevy Silverado/GMC Sierra 2007-09. I plan on using the stock catalytic converters without buying the custom "Y" pipe. Can I just cut the flanges off and reuse them on the end of the long tube headers. Meaning will the stock flanges bolt right up to the long tube headers ? As long as I have both O2 sensors (one before the catalytic converter and one after) the system should work with no problem ? Im trying to get around getting the "Y" pipe because I want true dual exhaust. I also plan on the exhaust shop to make a custom "H" pipe between each. Can this be done ?

 

Ok, one, no your stock y-pipe won't bolt up to those headers no way. Two, true duals aren't going to net you any real significant power increase, if any over a well designed y-merge single setup dumped. And third, a crossover pipe will pose no performance benefit unless it's placed between the two banks evenly for the pulses to hit it in sync. Off to one side will not do anything besides change the tone a hair. Fourth, having the exhaust flow through an extra 8-10ft of tubing will almost negate any performance gained from the headers, key word almost.

 

the stock y-pipe wont be a direct bolt on unless you weld it, question for you bro is if u have a reason youd like to keep the cats? reason i ask is they will rob u in power not by alot but a lil, and if you go ''true duals'' i would highly recommend an X-pipe over the H-pipe with 3'' pipes! , also you might wanna look in to a single 4'' exhaust
i agree in the 1st one but not in the 2nd and 3rd from my knowledge when we played with Cheyenne_87's truck we tried 4 yes 4 different types of exhaust systems lol on his cammed 4.8L 1st was the stock size pipe with a dyno max bullet made 322rwhp and 322rwtq 2nd we did a true dual 2 1/2'' with no cross over made 324rwhp and 312rwtq (-10rwtq) 3rd 3'' x-pipe with the 2 1/2'' pipes did 328rwhp and 323rwtq 4th and not his last lol 3'' x-pipe (cutouts also) with 3'' dual pipes on magnaflows both pipes dumps after his axles made 341rwhp and 328rwtq, now on my 6.2L i played with mine as well i took off my 3 1/2'' exhaust and did an 3'' x-pipe and 3'' duals did great but then i did the 4'' because of my turbo but before the turbo 4'' single was great

 

Awesome amount of information and experience there, man. Great post, thanks!

 

I agree, great information. Stuff like the above should be more clearly discribed in some sort of sticky/repository for others to add there information as well. It would save people alot of search time since someone obviously went through thousands of dollars in expirements lol.

 

Dam.good thread lol im.also.debating wether i.should go from.3 inch y pipe to true dual 3inch

 

Thanks for the post guys. Some great information 62nalide.
I agree with your very nice documented experiment.
I was going to try my best at what I thought will give me the biggest gains.
The X pipe is another consideration.
I want to keep the cats just kinda to stay legal if thats possible... HAHA.
I am not going to have any mufflers on it at all.
I disagree with you gbody6liter on a few things but thanks for letting me know about the flange.

gbody6liter do you have any dyno numbers to prove that? (Not trying to be a smartass)

edit: So no matter what I will have to buy the "Y" pipe for the flanges and then cut them for the dual exhaust part and weld new pipe to that ?

 

thanks man,

lol not thousands but it helps when ur buddy owns a muffler shop

 

if u do true duals no need for u to spend the extra money on it, IDK how to post pics but PM me ur email or number and when i have a chance ill take a pic of my buddies setup which is true duals so u can have an idea

 

On a 6.2L, dual 3" I can see being a benefit because of the power and size of the engine. Where was the x-pipe placed in this last system that was tested? I think most of the gain was from the dual 3" pipe myself. I've got 12+ years of exhaust fabrication under my belt and have done everything from stock replacements to race systems. I plan on running an x-pipe myself but will be putting it where it belongs, right in the middle as close to the engine as I can fit it. It will be modular so I can swap out mufflers and have different sounds for different times. Plus, it will allow me to dyno my muffler prototypes.