ARK Grip gains?
 

So I've searched to the best of my capabilities trying to find dyno numbers on this exhaust and have only been able to find the factory claimed 9.8 rwhp or something like that. I love the sound of this exhaust and it's not a deal breaker considering the small difference from say FI. Just wondering if there are other tests out there that show the gains of this exhaust? There are very few actual posts of dynos for this exhaust for some reason.

The manufacturer website's 10whp was done with a CAI installed and not from bone stock. This is just more of a curiosity than anything. I will most likely still go with this exhaust because of the sound.

when I had mines I gained 7 whp over baseline with the ark grip exhaust; that was without a tune. I'll look for the dyno graph

Do you know if the 18-20whp gains for the FI exhaust are post tune or before?

Those are the same as what is claimed by stillen also. I don't see a whole lot of difference in ark vs fi that would net FI that much more HP

Not sure if this helps, but my bone stock number was 270whp on 91oct. After installing my post maf hoses, K&N filters, 93oct, and ark grip exhaust my number was 302whp w/o tune. Not all mods were installed at once, the ark grip was the last thing i put on the car and is what i felt gave the most power. This was on a mustang dyno, my Z is also a 2013.