1320 Performance V1 Stainless Steel Header for the Polaris Slingshot

Header and exhaust
We really like the performance we are getting with the install of the header and exhaust.

Nice Header
Having been a mechanic for 45 years and installed many headers on performance engines this header is the quality of a Doug Thorley header. Very well made but for the price of the header, a copper seal gasket for the plug should be included since it's only 2.79 for 2. That's my only complaint. I still give it 5 STARS. As for the removal and installation goes, the exhaust manifold comes out very easy, a turn here and twist there and out she comes. As for the bottom exhaust bolts, YOU DO NOT HAVE TO REMOVE THEM! Install your new gasket on the engine. Upon installing the header push the bottom exhaust far forward toward the engine. The header can be tight but as you bring it in to the engine, PUSH DOWN ON THE EXHAUST AS YOU ROLL BACK THE HEADER TO CLEAR THE EXHAUST BOLTS AND THE BOTTOM FLANGE OF THE HEADER AND EXHAUST. It should go right in. Tighten all the nuts to specs.

So Long Annoying Highway Drone
These headers really did bring the best of both worlds to the slingshot (2016 for me).

The stock headers are very constrictive and as a result at highway speeds just drooooone on and it get's very old while road tripping. The new 1320 headers not only helped with the performance aspect of opening up a cars exhaust system but the sound change is split into 2 parts:

1) Heavy acceleration...sounds wicked, definitely a bit more loud than stock however it's much lower in pitch
2) Just cruising - because the exhaust system is less constricted while you are just putting miles on at 70mph the overall exhaust noise has been greatly reduced resulting in less of that higher pitched drone. About the only time it gets any louder compared to stock is going up a higher gradient slope.

Performs great, annoying installation
Good looking product, performs great, noticeable increase in power with an exhaust system. Problem is the middle top 2 bolts are directly behind the bends in the pipe making it impossible to get a torque wrench on for proper torque unless you have an Actual Dial-set torque adjustable crescent wrench which is an extremely rare tool and no local store had one. Ended up having to get a set of crows feet, put on a universal swivel adapter to that, then run a 8'' extension and then put the torque wrench on the end of that. Problem with that is that adding that many bits onto a torque wrench changes the torque output from the setting so i ended up having to tighten it by hand, torque wrench to close as i thought and then give it one bit more turn to make sure. Very poor design there considering you have to torque headers properly or they can crack or leak.

Great product
Real happy with quality of header. I watched video and then started by removing exhaust manifold first. I was able to put header on by removing exhaust manifold, unhooking 2 springs on muffler, moving it out of the way. I only removed just the bottom rear 2 bolts from head, not all as shown on video. They take a T7 torx socket. I did not remove any of the body parts. Be careful when reaching down to unhook bottom spring, there are screws that stick out that can catch back of hand. I did some test runs before and after putting on the header, and I feel there is an obvious improvement in performance. Looking forward to getting to my spot for high speed, to see if top speed has improved.