Factory 4.1 RCT System Basics
The Bike: 2014 KTM 450 SX-F
MSRP: $949.99 Starting at $610.39
Weight: 1.5 lbs (header) 4.15 lbs (slip-on)
Stock: 2.5 lbs (header) 5.25 lbs (slip-on)
As I’ve come to expect with FMF, the Factory 4.1 RCT Exhaust System is an amazing looking, well made product. The install is a breeze and really couldn’t be much easier – the hardest part was removing the stock system.
FMF claims the Megabomb/4.1 RCT Technology offers
- Low end to mid-range gains as well as broadening out the mid to top end power gains over stock.
- Reduces sound output as much as 1.5dB
- Increases output from stock motor as much as 3hp with a full system
Does this system fulfill the claims? I would say the description of the power it produces is pretty accurate. I don’t have a dyno, but I really don’t think it produces a 3hp increase on this bike. I also don’t think that it reduces the sound output. It’s pretty dang loud compared to the stocker. Maybe they’re talking about a decrease in noise with one of the rapid tuning system inserts installed?
There is a noticeable change in power characteristics when riding with the FMF 4.1 RCT system. The KTM 450 SX-F’s abrupt hit off the very bottom is smoothed out a bit (although it is still present) after that where there is a bit of a drop off in stock form, the FMF system pulls harder, making it possible to carry an extra gear in many situations.
That said I don’t feel the full system offers a huge performance performance advantage over the FMF Factory 4.1 RCT Slip-On with stock header. I would say the small noticeable difference is in the bottom end to low-mid, where the full system offers a bit more power and allows you to carry that extra gear a bit easier.
Over 30 hours of use this exhaust has held up very well. I have repacked it once, which isn’t too surprising, but other than that everything’s stayed tight, nothing has cracked, I have no complaints.
For this bike, you may as well save your money. A slip on is more cost effective, but it probably doesn’t even need that. That is, unless you are cutting weight from your bike one part at a time or just want an exhaust for cool factor, in either of those cases you should totally buy one.