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2014 YZ250F FMF full system 15% HP gain!

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I spoke with FMF and they claim that there is a 15% HP gain with the full 4.1 system....isnt that close to 6hp?  Doesnt that seem like a lot of gain?

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I dont see any reason why a company would lie about such a claim. It's not like theyre in it for money. Id like to see 3rd party tests

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It's a 15%gain when you multiply 7.5 x2

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When the 2014 YZ450F was released to aftermarket OEMs like FMF...their initial response what "what are we supposed to do with this"...in reference to how strong the motor already was.  Not a lot of gains to be made. 

 

Given the strength of the 2014 250f...does anyone really believe Yamaha (and everyone else) is leaving 6 HP on the table?  1.5%...sure.  15%...no way.

 

The only way to get those sorts of gains is to up the RPM band.  HP = Torque x RPM x  constant.  There is no magic.  You can up the RPM to create power, but the price you pay is exponentially increasing forces (reciprocating mass) and resulting drop in component life.  This is why a PC 250f costs $1200 Per HOUR to run..and why the life is about 2.5 hours.  I doubt FMF is going to match Mitch's pro built motor with a $850 pipe.  The physics just do not support it.

Edited by Blutarsky
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When the 2014 YZ450F was released to aftermarket OEMs like FMF...their initial response what "what are we supposed to do with this"...in reference to how strong the motor already was. Not a lot of gains to be made.

Given the strength of the 2014 250f...does anyone really believe Yamaha (and everyone else) is leaving 6 HP on the table? 1.5%...sure. 15%...no way.

The only way to get those sorts of gains is to up the RPM band. HP = Torque x RPM x constant. There is no magic. You can up the RPM to create power, but the price you pay is exponentially increasing forces (reciprocating mass) and resulting drop in component life. This is why a PC 250f costs $1200 Per HOUR to run..and why the life is about 2.5 hours. I doubt FMF is going to match Mitch's pro built motor with a $850 pipe. The physics just do not support it.

Thanks for clearing that up hahaha

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Me: Do you have dyno graphs for the 4.1 slip on?

 

FMF email response: We unfortunately don’t have any of that available.

 

 

My response: I hope I dont come across the wrong way but how does a customer know that an FMF slip on makes more HP then stock? If there isnt a dyno to prove this then how is it substantiated? Im interested in buying a slip on but I need some data to support claims.

 

 

FMF response: We go by our results in supercross and motorcross as well as word of mouth. The reason we have 80% of all top tier pros running our stuff isn’t because it looks cool. Its 100% race proven.

 

 

Me: I am looking for a silencer and possibly a head pipe for my 2014 Yamaha YZ250F. I mostly ride the track for fun ( I dont race), and trail ride. I was on your site looking at the different options for my bike but I dont know which to go with. I like the stock exhaust and how short it is. Do you have anything that is that size? If so are there any HP or torque gains....how much if so? I also need one that has a removable spark arrestor.

 

 

FMF response: Our 4.1 RCT would be your best bet you are looking at gains with the full system of over 15%

 

 

This is all copy and pasted from an email string of responses I had with FMF....very quick to respond, and I do think they make some great products.  Problem is I have spent 10 years of my life as an engineer in automotive exhaust system design and you will not add 15% more HP by not changing the pipe OD, or silencer back pressure.  I HIGHLY doubt that Yamaha has left 15% of performance on the table so that an aftermarket exhaust company can pick it up and go with it.  I would be shocked it you picked up 1-1.5hp from a full FMF exhaust system over stock. 

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I dont see any reason why a company would lie about such a claim. It's not like theyre in it for money. Id like to see 3rd party tests

 

lol I appreciate the sarcasim.  I would like to see third party data also.

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"FMF response: We go by our results in supercross and motorcross as well as word of mouth. The reason we have 80% of all top tier pros running our stuff isn’t because it looks cool. Its 100% race proven."

 

I am highly dissappointed in this response. Really? This is the best response a rep at FMF could give you. Lame. Saying that they go by the results in supercross and motocross? Ok so if I fab up some run of the mill exhaust system, pay Ricky Carmichael enough money to race it and he wins or does really well that tells me I have a pipe that puts out 15% more HP that stock? Word of mouth does not translate to dyno #'s either.

 

Yes their stuff IS race proven but not 15% HP proven. Not without a Dyno sheet.

 

All that said I am going with the FMF exhaust system. Once I get it I will run it on the dyno myself. I am willing to bet a gain of maybe 5% by itself with no other mods. I remember when people were bragging about putting an FMF full system on was giving them 3 hp on a 250F and 6 hp on a 450. I found that even to be questionable.

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I think the most MXA got out of an exhaust on the previous-gen YZ250F was not even 3hp. Like byz250f said, Yamaha really stepped up to get this new motor to the top of the class, I highly doubt they would leave that much power on the table due to exhaust. 

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This is all copy and pasted from an email string of responses I had with FMF....very quick to respond, and I do think they make some great products.  Problem is I have spent 10 years of my life as an engineer in automotive exhaust system design and you will not add 15% more HP by not changing the pipe OD, or silencer back pressure.  I HIGHLY doubt that Yamaha has left 15% of performance on the table so that an aftermarket exhaust company can pick it up and go with it.  I would be shocked it you picked up 1-1.5hp from a full FMF exhaust system over stock. by

byz250f,

 

    Apologies about the response you got from our tech support here at FMF Racing. We are going through a transition phase right now, with some new people coming into our tech department. Here is what I can tell you about the YZ250F System and also an attached chart for you. Hope this helps clear some things up for everyone. Not exactly sure where his 15% power increase number came from either. If you have any further questions, please let me know and I will do my best to assist you accordingly. Thank you and have a great day!

 

  Our system was developed for enhanced track performance Good pull for starts and linear power for tractability. A high peak power number with a crappy power band was not our objective. Also the weight of the system in Ti is approx three pounds lighter than the stock exhaust system.

 

See DYNO chart attached (Stock VS. FMF System both with race gas)

2014YZ250FRaceGasDyno_zps64a34ee6.jpg

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again, my new DBmag has an exhaust comparo...they state the FMF 4.1 system is the lightest and makes big power up top, and that bottom power is weak compared to stock.

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byz250f,

 

    Apologies about the response you got from our tech support here at FMF Racing. We are going through a transition phase right now, with some new people coming into our tech department. Here is what I can tell you about the YZ250F System and also an attached chart for you. Hope this helps clear some things up for everyone. Not exactly sure where his 15% power increase number came from either. If you have any further questions, please let me know and I will do my best to assist you accordingly. Thank you and have a great day!

 

  Our system was developed for enhanced track performance Good pull for starts and linear power for tractability. A high peak power number with a crappy power band was not our objective. Also the weight of the system in Ti is approx three pounds lighter than the stock exhaust system.

 

See DYNO chart attached (Stock VS. FMF System both with race gas)

2014YZ250FRaceGasDyno_zps64a34ee6.jpg

 

Nick thanks for the informattive response, and graph.  There looks to be a nice 2-3hp gain in midrange, and Top end.  Was this with a programer or just stock EFI tuning?  The weight savings looks to be key on your exhaust system for the 14 250F.  I will most likely be buying a 4.1 slip on for my bike.  Can you provide me with the size difference of the 4.1 vs the powercore(length of silencer)?   I am like how short the stock silencer is and would like to keep it looking that way if possible.

Edited by byz250F

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Nick thanks for the informattive response, and graph.  The weight savings looks to be key on your exhaust system for the 14 250F.  I will most likely be buying a 4.1 slip on for my bike.  Can you provide me with the size difference of the 4.1 vs the powercore(length of silencer)?   I am like how short the stock silencer is and would like to keep it looking that way if possible.

The Factory 4.1RCT is about an inch to an inch and a half shorter than our Powercore 4. The Powercore 4 is right around the same size as the Stock OEM. Hope this helps clear things up for you and again if you have any more questions please let me know. Thank you and take care!

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The Factory 4.1RCT is about an inch to an inch and a half shorter than our Powercore 4. The Powercore 4 is right around the same size as the Stock OEM. Hope this helps clear things up for you and again if you have any more questions please let me know. Thank you and take care!

 

My buddy bought this for his 2014 YZ250f and it was atleast 4 inches longer then stock.  I didnt like how it stuck so much further out past the number plate thats why I havent bought one yet.  But your saying that the Factory 4.1 slip on is 1-1.5 inchs shorter then stock?  Can you provide a picture of a bike with the 4.1 on it?

 

  http://www.ebay.com/itm/NEW-FMF-POWERCORE-4-HEX-SLIP-ON-EXHAUST-MUFFLER-PIPE-2014-YZ250F-YZ-250F-044423-/291075365702?pt=Motorcycles_Parts_Accessories&hash=item43c5719b46&vxp=mtr

 

 

Here is the stock slip on:

 

s1200_bike.jpg

 

2014-Yamaha-YZ250F-G.jpg

 

Which model is this slip on?  Because it looks to be about 4 inchs longer then stock.

 

IMG_72511.jpg

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The Factory 4.1RCT is about an inch to an inch and a half shorter than our Powercore 4. The Powercore 4 is right around the same size as the Stock OEM. Hope this helps clear things up for you and again if you have any more questions please let me know. Thank you and take care!

Is it beneficial for me to go with the complete GYTR FMF exhaust system? That is the pipe I was looking at and I have heard nothing but good about the FMF pipe doing exactly what you stated. I like to have the power linear all the way through the rpm range and it sounds exactly like what I am looking for.

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The Factory 4.1RCT is about an inch to an inch and a half shorter than our Powercore 4. The Powercore 4 is right around the same size as the Stock OEM. Hope this helps clear things up for you and again if you have any more questions please let me know. Thank you and take care!

 

Also is this the Titanium or SS system?  Do you see any gains of one over the other, or just weight loss?  

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