HMF Engineering Full System
About HMF:
When thinking of high performance exhaust systems for your quad, one name always comes to mind. HMF. HMF has certainly created a lot of happy customers and has always created excellent products as well as fantastic customer support. When HMF contacted us for a review of their new full system for the YFZ450, we simply couldn't refuse.
Inspection:
When the big brown truck finally arrived a few days after our purchase we were pleasantly surprised at how well this thing was wrapped. We knew HMF took pride in their pipes, but never thought in wrapping and shipping as well. The pipe and head pipe arrived both in popcorn packing and each part was wrapped in bubble wrap. A very nice touch to insure safe delivery of the product. Once everything was unwrapped we sat there in amazement at how gorgeous this pipe really is. Not only does the pipe look drop dead gorgeous in red, but it also matches the frame almost perfectly. The pipe felt very solid and the quality was above and beyond anything we've ever seen. Definitely above any major manufactures who produce pipes. Most manufactures do average welding jobs, HMF was spot on and flowed perfectly in one direction! We also inspected the head pipe closely as well. One thing to note though is that while looking into the head pipe, there was a lot of popcorn packing stuck in there. Once we thought it was out, it really wasn't. So be sure there's nothing left in the pipe! As for everything else, HMF gets an A+ in the quality department.
Installation:
Installation of the pipe went rather easy. Taking the old head pipe and pipe took no more than 5 minutes. Installation of the new pipe took about 10 minutes. As for jetting, we went ahead and ordered a JD Jetting kit to make sure jetting was spot on. Once jetting was done, we also took our air lid off to get the most power.
Ride Report:
Now for the fun part! We took our YFZ450 out for a little ride to see how much power we had gained, and where it was to be found. First impressions apon starting the bike are that this thing is loud! If you're worried about sound levels in your area, we suggest that you also purchase HMF's quiet core to quiet things down to legal levels. (We will talk more about the quiet core later on) Once we found a nice open stretch of road, we let it rip! One word, WOW! If you thought the YFZ450 was fast stock, JUST WAIT until you put a new exhaust system on! The bike just keeps pulling and pulling like nobody's business. Once you get into the upper RPM range, the engine just comes alive. You start to struggle trying to keep your arms from ripping off from all the torque. Most of the power was gained in the mid to upper RPM range.
Quiet Core:
Since the pipe was just a tad to loud for our riding area, we went ahead and ordered their quiet core. HMF claims that you only lose 5% HP, while also taking noise levels to a legal 91 DB. After putting the quiet core on our bike, we were a little skeptical thinking that we were only going to lose 5% HP. After starting the bike up, we noticed a huge difference in sound levels. While riding the bike, you hear the engine more so much like the stock pipe. So the real question here, how much power did we lose? Well, based on our "butt" dyno, can't say that we lost any power that's noticeable. The bike still pulls strong in the same RPM range, still has a nice bark and keeps our neighbors happy!
Conclusion:
So is it safe to say that we like this exhaust system? You better bet so! The difference that it made is night and day. Although the YFZ450 is fast stock, its even faster when piped and jetted. Overall, we have no complaints about HMF's exhaust system. It's put together flawlessly, it sounds great, and put out incredible gains. What's there not to like? So what are you waiting for? Hurry up and order your HMF exhaust system!
www.HMFEngineering.com
***Check back soon for videos of the system with and without the quiet core***
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