FMF VS Pro circuit

I was looking at the FMF ti-4 with stainless mid pipe and power bomb header or the pro circuit t-4 pipe

wich one is lighter and gives most power increase

Me's thinks it is FMF.

PC Ti-4 is all ti one peice (mid/muf) 4lbs and can use the stock header. FMF you have to get the muff and mid pipe. PC is loud though. :)

I have the t4 system on my bike right now and its great. Other than the fact that people can hear it in neighboring states. My FMF Ti4 system w/ stainless mid and stainless sx powerbomb comes in on the 28th. I'll be out the following weekend with both back to back on the same trails to get as close as a comparison as possible. But I gotta say I'm really happy with the pro circuit right now.

i recomend the new ti-4 PC its titanium and it gives so much ponies. its awesome and i highly recomend it.

Yea Big Fat & Slow, hopefully i can get all my stuff together and we can get out and test our new pipes. I agree that PC system was awesome on your bike, plenty of rip and power. Hopefully our FMF Ti4 systems will work just as well.

is the pc just the silencer or is it the whole deal

the FMF ti-4 is 420

I thought the PC was about 420 too but is that for everything

FMF definitly

01 yz426fto much to list :D

03 yz250f stock but not for long :)

I'm just curious but for the people that say "FMF definitly". I had a question? Have you been able to try both? What other pipes did you like and why? What makes you say FMF. I've had a full procircuit exhaust and an fmf powercore 4 and sx powerbomb. I can tell you that the pc pipe has much better throttle response and low end. Also the pc is better fitting. The joint at the header/mid pipe is tighter and you don't need those weird o-rings to mount the rear silencer. When I get my fmf ti4 system i will let you know what i think back to back after next weekend.


OK, I hope you appreciate this mad-wack load of typing. This is from Dirt Rider, April 2001. They have a YZ250F pipe shootout (hey, c'mon, it's been long enough, time for some one to do a new one!). Anyways, here's what they said about the FMF and Pro Circuit:


Power Core IV: $269.99 rear section only

Power Bomb Motocross Header: $189.99

Power Bomb Supercross Header: $189.99

Spark Arrestor: No (SA model available for $289.99)

Decibel level: 105

Material: Stainless header, mid steel rear section with ermic coating, muffler canister is aluminum with a stainless steel end cap.

Starting with thte PB motocross header, the FMF exhaust builds a powerful punch up top over the stock exhuast. This setup revs very quickly while making horsepower before the rev-limiter shuts her down. Its only glitch is that it is lacking some roll-on power down low. If a track does not offer up traction, the engine wants to rev right through the meat of the power and tends to demand the rider shift more often or it bangs off the rev-limiter too easily. With the addition of the PB supercross header, the system helps buid more roll-on power but still does not have as much meat in the mid compared to the Big Gun, Dubach, Pro Circuit or Yosh. The power still features that hard-hitting top, but with a slight sacrifice to the pull. The FMF combos are best suited for aggresisive riders who like a quick-revving bike and are willing to compromise some tractable meat down low and in the middle of the power curve.

Pro Circuit:

T-4: $476, complete system

Spark Arrestor: Yes, removable

Decibel Level: 104

Material: Stainless steel header and rear section with aluminum canister and aluminum end cap

PC is on its game with the YZ250F and offers a pipe configuration very similar to the Dubach and the Yosh. The power is very progressive across the board without forfeiting bottom and mid for arm-jerking top-end. The PC still pulls to the upper ranks, but not as intensely as the DSP, FMF or WB R4. The PC unit has a broad power curve that is very versatile. This unit is perfect for riders who are looking for performance without robbing Peter to pay Paul.


that's it, not saying either is better or worse, just better or worse depending on what you want..


so who won the shoot out? PC?

there was no clear winner of the shootout. I mis-spoke, it was actually just an exhaust test, giving results for each pipe, more than a shootout.

This summary paragraph from the article says it best:

"During our test sessions, we uncovered two different performance characteristics and one very obvious fact. The latter is that with just an exhaust system, the YZ250F unleashes hidden horsepower Yamaha must have overlooked. The pipe combos either buit a lot of quick-revving performance from the upper-mid until the engine starts to bounce off its 13,500-rpm rev-limiter, or they built a stronger base across the board with a sacrifice to the other units rocket-ship power up top. Rider preference will dictate the best breather for the application."

I just put the TI-4 on my bike and it is louder than the space shuttle.

I herd the yoshimura is about as quiet as stock, could you give us the review on it along with the decibl lever. I am tired of the noise factor of wb-r4 on my crf and dont want anything that loud.

I aim to please (actually, very happy since I just got done riding my studded XR100 on the ice, loads of fun!). Here is the Yosh write up:


RS-3: $559, complete system

Spark Arrrestor: Yes, removable

Decibel Level: 102

Material: Polished stainless steel header and rear section with titanium muffler canister and polished aluminum end cap.

Of the units tested, the Yosh system is top-notch when it comes to construction and craftsmanship. The unit is held together with roadracing-style slip-fits with spring fasteners. This is also the only pipe in our test that allowed us to mount up the stock heat-shield, a rea plus in our book. On the track the performance mimicked the look of the exhaust. Although the Yosh does not have as much punch up top compared to the DSP, FMF and WB R4, it makes up for it in overall performance and its super midrange pull. This arrangement offers up a very tractable roll-on power down low and keeps pulling into a meaty midrange all the way up to redline. The pipe allows the engine to pull up top in all conditions without building power too quickly and revvving too fast. The Yosh was a favortite among our test crew because it performed well at both tight and wide-open tracks with changing dirt conditions.


dude, it was very hard to not pick this pipe for my own. Quiet (relatively at 102 decibels), and a great all-around pipe (according to the testers), what's not to like? I'm taking a chance on the M4 being similar, hope I'm right! I also hope it's close to being as quiet.


I have a question. When you said the yosh was relatively quiet at 102. Did you test it or was that from the Magazine? Does anyone here know how the magazine test the sound. Do they do it at idle or according to the ama 20 inch test at half throttle?

It's from the magazine (I've never SEEN any aftermarket pipes for the 250F, I only know what I've read). Nope, don't remember how they test for sound, I can look tonight whence I get home from work.

Thanks for the reply on the yoshi.Decibel levels are not progressive so the yoshi appears as quiet as stock, while the others are way way louder at 104 and 105 so my pick is easy!

To be correct, they have to test the bikes/sound at certain RPM (usually around 5,500 or roughly half of the peak RPM) - strange that they tend to use 5,500 when half of 13,500 is 6,750?! :) The stock is 102 DBs so the Yoshi is similar.

I see the FMF Ti-4 tested around 105 DBs, I didn't have a tachometer but my FMF Power Core 4 tested around 110 DBs at 1/4 throttle - LOL "louder than the space shuttle"... :D

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