FMF has helped us on many builds and you may be wondering why do we use them so much? Well… A couple reasons are because FMF is a great American made company, they are easily accessible to us dumb media people and they actually care about the results of their product. If for whatever reason they missed the mark on a muffler setting they are willing to make changes asap to make their product even better. There are only a few companies that are easy to work within this business and FMF is one of those.
Suzuki hasn’t nabbed a shootout win or have won any professional races in quite sometime for that matter, but that doesn’t mean the Suzuki can’t be a great bike for the motocross enthusiast. One of my photographers/test riders Dallas Dunn purchased a RM-Z450 because this is what he could afford and he wanted to ride a dirt bike. Suzuki is selling their machines at a much lower price than other manufacturers and that is important for the growth of our sport. We need companies like Suzuki to stick around and help this sport grow. With that being said, I wanted to try and get the heavy monstrosity that is the RM-Z450 muffler system off and get an FMF 4.1 system on, in order to get you guys some feedback on what it can do to the RMaRMY’s power character.
First thing’s first. We picked stainless steel because it costs less and is more durable than a titanium slip fit joint. The titanium joints are known to wear out a little faster and you’re not going to save a crap ton of weight going to titanium. If you’re the type of rider that wants lightweight and looks then titanium is your jam, but if you’re looking to just lose some weight over stock and get some durability, there is nothing “not cool” about stainless. Speaking of weight, the stainless FMF 4.1 system weighs in at 6 pounds 11 ounces, which is almost a three pound weight loss from the stock piece. WOW! Bolting on the FMF 4.1 system is simple and takes almost not time at all.
On the track the FMF’s muffler pitch has a deeper more throaty pitch to it and sounds clean (with stock or lean couplers installed). We will say that you will not get a noticeable amount of more bottom end with the FMF 4.1 system installed, but what you will get is a cleaner, more linear, longer pulling power than the stock system. Out of corners you will feel more connection to the rear wheel and an overall lighter revving feel. It’s tough to find more connection when getting a lighter revving feel, but for whatever reason this is how the Suzuki’s engine and FMF system blend itself together. Pulling second/third gears longer is made easier with the FMF installed, so if you want to be slightly lazier with your shifting after the corner (leave it in second gear longer), the FMF system can provide that for you. One thing you will not be getting is more third gear recovery, so if you’re looking to lug the RM-Z450 more with the FMF 4.1 in third gear, it will not magically give you a ton more pick up in third gear. That area of the power remains similar to the stock muffler character. The over-rev of the 4.1 is noticeably better with the standard coupler, but if you’re using the white (lean) coupler you may want to give the stock coupler a try again to gain even more over-rev from the stock system. Going to the white coupler with the FMF 4.1 will give you slightly less over-rev, but it still will have more than that of the stock system.
For $749.99 the FMF 4.1 stainless system on the 2020 RM-Z450 is a good upgrade from your heavy, slightly lethargic feeling stock muffler engine delivery. Visit fmfracing.com to get yours or you can go to keeferinctesting.com and click on the RMATVMC banner to take you to their website to purchase.
Stock System 9.07 oz
FMF 4.1 Stainless System 6.11 oz