After a lot of internal debate over whether to choose the M4 slip-on vs. the lower-cost alternatives, I decided to give Devil a try. I first contacted their support since I couldn't find any reviews or even pics online of this exhaust installed. The person I had correspondence with at Devil confirmed that indeed this was a new product.
I knew this was going to be a gamble, but for less than $100 more than the M4, and without having to hack apart my stock exhaust, I decided to give this a go. Total cost with shipping and tax was $500 even. The exhaust was shipped the same day as the order and arrived in a timely manner.
When the box arrived, I was initially perplexed at the box, which was a giant cube. I have experience with installing exhaust systems on many bikes and cars, and had never seen one arrive in such a way before.
Upon opening the box, the 2 main pieces of the exhaust were each in a plastic bag, which were put together in another plastic bag. There was no packing separating the 2 pieces, and the large box was loosely packed, allowing the pieces to rub/bang together during shipping.
Before I attempted to install, I contacted Devil to let them know, and sent them pics of the dings and dents. They said I could pay to have it sent back and they would refund my money. That was the only option since they were out of stock and couldn't send another. Since I plan on wrapping most of this exhaust anyway, I decided to suck it up and install the exhaust.
I've heard of fitment issues with other exhausts, especially at the engine block, and this was no different. Based on other reviews of exhaust systems, this one seemed more "off" than what I have seen online. I honestly wasn't sure if I was going to be able to get this thing to fit on at all.
The biggest issue was the exhaust clamps that attach to the head bolts wouldn't line up and fit through the holes provided. Not even a little bit. I had to drill out 1 hole on each clamp large enough to allow me to slide the threaded bolts from the motor through.
Once I was able to get this done, the rest was fairly simple, except for the springs that were not even close to fitting the distance between attach points at the top. Pulling on these even broke the spring puller I had. The only one I was able to get attached was the one underneath that hold the 2 parts of the exhaust together.
Currently, the spring attach point is touching the bottom of the oil pan, and the muffler is touching the swing arm. I plan on removing the whole thing again this weekend and adjusting everything to hopefully fit better.
While I do not have a ECU tune yet, the sound is AMAZING! Very deep and bassy, with no raspiness at all. Once I get over 5k RPMs, I can't hear it at all- it's all wind noise over my helmet.
I have no idea how this exhaust compares to the others as I have not had the chance to hear any others in person.
A big point of this system is the 2 resonators, where all others only have 1, or none at all. I didn't want anything too loud, and even this is a bit much, but I am very happy with the sound overall.
Also, there are no instructions what-so-ever included with the Devil exhaust. Link attached are some pics I took during the install. Note the welds as well, which I find to be less than average. Let me know if you have any questions.
Link to exhaust: Devil Exhaust