Anyone use the FMF Powercore IV Quiet Can?

I was browsing the TT store killing time and I ran across the FMF Powercore IV Quiet exhaust. Has anyone used one of these things? Are they actually quieter than stock? If so, what did they do to your power?

It could be that they have updated or changed the design/engineering of this product, but the one I bought about 1.5 years ago was an overpriced piece of junk in my opinion. Why? Because the rear hanger just loops around the can, it isn’t rigidly affixed like the stocker and most aftermarkets. This matters because the Q is long, extending well aft of the hanger. Since the hanger isn’t welded the can is allowed to rock or pivot about the hanger, allowing the weight of the portion that extends beyond the hanger to apply leverage to the front of the can where it attaches to the collector with 4 self-tapping screws. After about 2 months of use mine came apart at this joint, ripping the holes out of the collector. I’m sure it could have been easily repaired, I probably would have just welded it to the collector, but it was during a race and I never recovered the parts.

This irritates me because this half-ass design is unnecessary, and probably used so that FMF can use the same part for a lot of different bikes. At the prices they are charging they can afford to make each pipe fit a specific application, just like Pro Circuit (if you want to compare a well engineered product vs. a glob of marketing hype IMO just put any PC product next to any FMF product).

All of this is a real shame, because the damn thing worked pretty well. It did kill a bit of low end and midrange “hit,” but my 426 still revved very well like the stock pipe, and it was pretty quiet. In my case it tended to richen up the idle and pilot circuit just a tad. For comparison’s sake it was almost as quiet as a stock KTM 520. When it “got on the pipe” it was louder, but at steady throttle/rpm it seemed about the same noise level as a stock KTM.

However I have seen at least one post where a guy failed a CA sound check w/ their FMF Q (but I’m sure they could fail anything if so inclined).

Anyway if you are aware of, and keep an eye on the mounting weakness issue you may not have any problems, as far as I know I’m the only guy here who has had one come completely apart like that.

Speaking of, what IS the right way to get that loop around the can? Mine came with a little silver button to "reduce failure of the strap hanger" so it says in the doc.'s, but I have typically used washers on (both) sides of the strap to secure other systems, does this "button" go on one side, inside? outside?

I've tried looking around a bit, but I haven't found any pictures of one installed. Most of my experience prior to now has been with streetbike systems, adding to my confusion.

Any ideas? Many thanks!

-Chris :)

...does this "button" go on one side, inside?

I don't remember such a part on my Q, but if I had to guess I'd put in on the inside by virtue of process of elimination:

You don't want to put it between because the loop won't have a good hold of the can that way, and putting it outside has no affect on anything that I can see.

Hope this helps. :)

I've got a Q pipe that's about a year old and the only time it's on the bike is when it's absolutely necessary. The mounting system is crap but it is effective at cutting noise. I was tested at Kennedy Meadows last year at 92db, pretty quiet compared to others. However, it felt to me that it killed a big part of the hit of the bike from the bottom to the top. I used it at sea level to see how it affected the motor and it seemed to be the same as at the higher elevations...a power killer. But depending upon where you are riding, it may be a necessity.

Jus my .02

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