Id just do a y pipe personally. I dont think you'll see any noticeable gain between the two.

But either one should work fine. Just depends on what your plans are for the rest of the exhaust.

 

I know hp gains from catback are debatable. I will be getting a boost from the LTs and the catback will be determined by which LT I choose. The SW will make it an X and the TSP or Kooks will make it a y.

Sound matters, but not as much as desire for noticeable gain. If the gain is marginal between the two, then I will save a buck and go with the y. If true dual is 10 or more hp (can anyone prove this with a dyno test?) then it is worth it to me to get the x pipes. Not crazy about the raspy sound but I could muffle that out with a resonator or silencer if it is that bad.

 

Like I said, I doubt you'll see any difference between the long tubes with a Y pipe, and long tunes with that X pipe.

Especially when the stainless works are twice the cost of the TSP with their catted y pipe. Would need to be a heck of a gain (if any) over the Y pipe for justify the extra $1000+.

 

If you get headers you will need a tune. The lower back pressure will change everything.

 

As long as the single pipe is sized correctly after the long tubes I doubt it is going to matter that much. Now if you are planning on more performance upgrades, such as forced induction, at some point dual pipes may be worth it more than a single just to get overall exhaust tubing larger (and more choices for mufflers also).

 

I would like to get a Whipple down the road, that is a bit of what I am considering in the decision. Serious forced air. Financially that is not something I am ready to do, could be a year or two.

If I do go with a supercharger I don't want to have to redo exhaust or other choices along the way.

 

Unless you plan on pushing some SERIOUS power, you will not in anyway be limiting yourself with 1 7/8" headers and a 3" Y pipe.

Just go look up what guys who are running superchargers run. There are tons of them running texas speed and speed engineering headers and their respective Y pipes. Either catted or offroad.

I have read that much over 700hp you really dont want cats anymore. But again, that's far beyond just putting a supercharger on. Especially these motors. The previous gen of motors (LS based) seemed to readily take more power with less work and fewer issues than the newer LT based motors.

 

Ditto to the above, don't believe x or y in your case will matter either way since its not a high hp application.

1 7/8" y pipe will be plenty for just a bolt on SC and other little supporting mods.

Do you know if you would like to run a single exit or dual exit out the rear or axle dump or what?

side note I rode in a 2015 supercharged Silverado recently and he had LTs without cats and it was VERY tame sounding until you open the cutout.

 

Dual outs, and glad to hear about the S.C. with LTs.

 

being that you have the 6.2 im torn on suggesting that the dual setup after y pipe needs to be 3" or 3.5". With a good tune you should be around the 475-500 mark at peak hp IIRC. Better to be a little under than too much over though. if you don't plan on nitrous or more than 10psi I would say dual 3" will suit you well for that setup. (this is just my opinion from the reading that I have done when spec'ing a SC for my 5.3l)