Z1 did an awesome video comparing multiple exhaust with sound clips and dyno. The range of exhaust included single exits and duals of different diameter.
I'm going to post the dyno numbers of each as a comparison

This comparison definitely shows that singles do provide the most gains for out platform.

Dual style diameter don't seem to have much difference in gains between 2.36" to 3.0", but 2.25" might be too small.
Tony at Motordyne did a study that saw 2.5" y-pipe primary diameter provided the best peak power and best average torque. 2.0" y-pipe primary diameter yielded the highest tq but low on hp. 2.25" primaries were better but not as good as 2.5".
https://motordyneengineering.com/sca...pressure-myth/

Baseline was 312.2 whp / 250.3 wtq

Tomei (3" single / paired with tomei y pipe) = 330.3 whp / 262.2 wtq

Z1 Race Single (3" / paired with z1 resonated y pipe) = 328.3 whp / 257.5 wtq

Z1 Race Dual (3" y-back dual early split with silencers / paired with z1 resonated y pipe) = 326.7 whp / 259.3 wtq

Z1 Touring (3" y-back single with late dual split / paired with z1 resonated y pipe) = 327.6 whp / 264.0 wtq

Motordyne (3" y-back dual early split, y section part of system) = 326.3 whp / 259.2 wtq

ARK Grip (2.5" x pipe dual) = 323.4 whp / 254.5 wtq

Fast Intentions (2.5 x pipe dual) = 328.0 whp / 259.2 wtq

HKS (2.36" true dual) = 326.9 whp / 256.3 wtq

Invidia Gemini (2.36" x pipe dual) = 327.0 whp / 259.8 wtq

Borla (2.25" h pipe dual) = 323.1 whp / 258.6 wtq

 

Nice bit of research, Panda! Well done!

For dual tip setups, Fast Intentions, FTW!

 

This guy eviscerates the Borla kit. Yikes! The HKS seems really nice, and sounds familiar.

Fun video, but entirely a marketing promo for Z1.

 

very much a marketing stunt but still some good information out of it.

I plan to do a dyno comparison similar to this but with different y pipe like the 2.5” z1, 2.75” ISR, and a 3” primary y pipe from Henko Autolab.

 

Nice post @projectpanda13

"horsepower is what people buy, torque is what they drive"

With that said, I think there is a typo in the Z1 Touring catback and the 364 wtq should be 264.

264 is still impressive. Amazing how close all of these are to one another.

 

thanks for catching that.

Yea, for the most part, all exhaust will make roughly about the same. Its best to just focus on achieving the sound an individual wants.

 

And style right? If they made a rear lower diffuser with a single exhaust exhaust indent, I may consider a single outlet with the right tip as this was the stock look on a G35S. Without the modification and a huge can hanging down, it doesn't look right to me.

Note that the mufflers on the G35 were very good and many tried to find a higher performing aftermarket muffler that never sounded as good or performed as well as the OEM muffler. All that generation of sedan needed was a midpipe from a coupe (bolt on), or 370Z (with extensions).

 

Adding more since Z1 also did an exhaust comparison for a 350z HR also.

Z1 Touring (3" single to late split dual / paired with z1 resonated y pipe) = 280.5 whp / 251.2 wtq

Z1 Single (3" / paired with z1 resonated y pipe) = 282.0 whp / 255.4 wtq

Tomei Single (3" paired with tomei y pipe) = 282.9 whp / 253.6 wtq

Motordyne (3" y-back dual early split, comes with own y section) = 283 whp / 255.9 wtq

HKS Hi Power (2.36" h pipe dual) = 279.9 whp / 250.9 wtq

Invidia Gemini (2.25" x pipe dual) = 282.2 whp / 252.3 wtq

Magnaflow (2.5" single to single large rear muffler with dual tips / used stock y pipe) = 277.8 whp / 248.0 wtq

 

This gets stickied.

Again, this is a fantastic bit of research, Panda. And you're right about that video existing solely so that Z1 can say their exhaust is #1, but like you said there is some invaluable analysis here, and a few chuckles. Undressing the plastic from that burnt TI exhaust tip to slow **** music was hilarious, even though it went on too long.

I wish he went into more detail in the design differences, and didn't just gloss over the Helmholtz resonators in the Ark and Motordyne kits. And the way he routinely dismissed kits that had tips welded to the cans, as if the whole world has aftermarket rear diffusers. That was pretty annoying.

To my ears, the HKS and the Fast Intentions kits both sounded and looked the best. Cabin noise is livable at speed, and the roar at WOT for those setups is just downright sexy. Those two should have been #1 and #2.