My new exhaust system

Cool! Can you share a pic of yours and show your calculations? Definitely more interested if there's actually MPG on the table...

 

I'm worried about the towing noise as well but I ha e all winter to enjoy it as-is haha. The factory tail pipe has some complex bends that won't be possible with off the shelf universal bends so would need mandrel bender or pie cuts to create one. Might be easiest to Y into a single 3.5" or 4" so you only have to make one

 

That Z pipe is cool, reminded me of that Borla kit as well. 3D printing metal is really making complex, low production parts possible now. Incredible.

 

I'm not even gonna try and match the factory bends. I'm just going to make it as simple as possible.

 

Straight out to the passenger side corner, a la the new Chevies is about the simpliest to clear the spare tire:

 

That's essentially what I'm going to do.

 

I did a 2-1 muffler and single 3" tailpipe out the back using this:
https://www.mandrelbending.ca/colle.../3-stainless-steel-universal-truck-tailpipe-1

 

I wonder what a 2 into 1 would do to the sound or flow.

 

Great find, how was the fit, close enough?

 

Mine sounds great to me, but a bit too loud with my flowmaster super 44. I'm going to change to dual muffler with a Y-pipe after. As long as single 3" isn't too small for your power goals, which for most it isn't, I would think running two into one with a proper Y would increase scavenging and flow over having two tail pipes that are bigger than most need. Just my opinion though.

 

Thanks. It's surprisingly good. Was exactly able to get enough clearance from the spare tire and leaf while getting the exit angle I wanted. Very happy. Built my entire exhaust with parts from lyells. They had every bend I needed and expanded any of the ends I wanted for free. Was very affordable and free shipping to me in Canada. Highly recommend them!!

 

Looks decent. What size is your spare tire?

 

Umm lol I have no idea to be honest
So it's probably the stock original one... lol and I'm running 33.5" tires.
I could have easily gave myself more clearance at the tire if needed, especially if I made one cut and turned a pipe. Which I may have to do after I lower the truck anyways.

 

Ordered some tubes and elbows to build Helmholtz-style resonators for my setup. Once the system is fully up to temp, the drone really isn't bad at all but when the system is cold, which is 50% of my trip to work and back, it is annoying. As the system warms up, the drone range is from about 1500 to 2200 RPM. I plan to use clamps initially so I can play with the length of the resonators to find the sweet spot, starting with known length DD uses initially.

As I understand it, j-pipe style resonators cover about +/- 250RPM range. But I have about 750 RPMs to cover as the system warms up. The thought occurred to me that since I have to build two of these, could I make each slightly different lengths to cover the drone range more. It wouldn't be as effective cutting down the drone completely like equal length resonators at a target RPM, but if I could kill the drone ~50% across a wider RPM range, that might be better!