FMF 4.1 vs Pro Circuit T-6

DawsonBMX54
Edited Date/Time 12/12/2019 11:54am
Hey I have a 2018 KX450f and I am looking at throwing an exhaust system on it for the new season.

I am currently looking at the FMF 4.1 with the Powerbomb Header and also the Pro Circuit T-6 system. (Both systems would be the stainless steel option)

I was just wondering if you guys have any experience with these systems and which one you would recommend or think would be better and why. I am also considering the RS-4 system from Yoshimura so if you have any experience with this one too that would be greatly appreciated.

Thanks Guys Smile
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Bennett59
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Bennett59 12/5/2019 9:27pm
12/5/2019 9:27pm
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of the fmf and the little more over rev it provided. The procircuit was good but it always felt as though it signed off earlier.
Never used a Yoshimura on my Kawasaki but I did on my Suzuki, Honda, and currently have one on my Yz450f. The yosh always seem to just have a nice liner power curve smooth hit, and good power throughout. Hope that helps
T-Fish
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T-Fish 12/6/2019 1:47pm
12/6/2019 1:47pm
Spend the money on a Twisted Development mapped Vortex ignition. It’ll be a million times better than an exhaust of any brand.
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DawsonBMX54 12/6/2019 4:17pm
12/6/2019 4:17pm
Bennett59 wrote:
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of...
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of the fmf and the little more over rev it provided. The procircuit was good but it always felt as though it signed off earlier.
Never used a Yoshimura on my Kawasaki but I did on my Suzuki, Honda, and currently have one on my Yz450f. The yosh always seem to just have a nice liner power curve smooth hit, and good power throughout. Hope that helps
So if you had the choice based on personal experience, would you go FMF or Yoshimura for your next bike?
Bennett59
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Bennett59 12/6/2019 7:36pm
12/6/2019 7:36pm
Bennett59 wrote:
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of...
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of the fmf and the little more over rev it provided. The procircuit was good but it always felt as though it signed off earlier.
Never used a Yoshimura on my Kawasaki but I did on my Suzuki, Honda, and currently have one on my Yz450f. The yosh always seem to just have a nice liner power curve smooth hit, and good power throughout. Hope that helps
DawsonBMX54 wrote:
So if you had the choice based on personal experience, would you go FMF or Yoshimura for your next bike?
I think the fmf tend to have a more Hard roll on power, I run the yosh Now cause I like it’s a little less explosive so keep a steady flow and less energy. I’d run either but For me I’m on the rider support for Yoshimura so I’d personally run the yosh, and they have always been real helpful if you have problems or need to send in your system for fixes they have a nice repair program system comes back looking brand new. The ecu on bike can change a lot to like T-Fish said and change power curve even with any of the exhausts to perform how you want.

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omalley
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omalley 12/6/2019 9:33pm
12/6/2019 9:33pm
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip.

I never rode it with the stock pipe, but from my previous Kawis, the PC typically added a bit of bottom and longer rev. The remap added more everywhere, got rid of popping and hot running (which was bad stock), and believe it or not, changed the tone of the bike. It might not mean anything in the grand scheme, but I’ve had several folks comment that my bike sounds different than anyone else’s, in a good way.

I have yet to hear an FMF exhaust on a 4-stroke that I like. They all sound like the packing is blown from day 1. Just my 02.
DawsonBMX54 12/7/2019 5:50am
12/7/2019 5:50am
Bennett59 wrote:
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of...
It’s kind of preference, when I had kx450s I preferred the FMF my self over the procircuit. For my riding style I preferred the power of the fmf and the little more over rev it provided. The procircuit was good but it always felt as though it signed off earlier.
Never used a Yoshimura on my Kawasaki but I did on my Suzuki, Honda, and currently have one on my Yz450f. The yosh always seem to just have a nice liner power curve smooth hit, and good power throughout. Hope that helps
DawsonBMX54 wrote:
So if you had the choice based on personal experience, would you go FMF or Yoshimura for your next bike?
Bennett59 wrote:
I think the fmf tend to have a more Hard roll on power, I run the yosh Now cause I like it’s a little less explosive...
I think the fmf tend to have a more Hard roll on power, I run the yosh Now cause I like it’s a little less explosive so keep a steady flow and less energy. I’d run either but For me I’m on the rider support for Yoshimura so I’d personally run the yosh, and they have always been real helpful if you have problems or need to send in your system for fixes they have a nice repair program system comes back looking brand new. The ecu on bike can change a lot to like T-Fish said and change power curve even with any of the exhausts to perform how you want.
So it sounds like either the FMF or the Yoshimura would be a good choice then. They are both pretty systems so it’s hard to choose haha. I appreciate the help man thanks.
DawsonBMX54 12/7/2019 5:51am
12/7/2019 5:51am
omalley wrote:
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip. I...
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip.

I never rode it with the stock pipe, but from my previous Kawis, the PC typically added a bit of bottom and longer rev. The remap added more everywhere, got rid of popping and hot running (which was bad stock), and believe it or not, changed the tone of the bike. It might not mean anything in the grand scheme, but I’ve had several folks comment that my bike sounds different than anyone else’s, in a good way.

I have yet to hear an FMF exhaust on a 4-stroke that I like. They all sound like the packing is blown from day 1. Just my 02.
The exhaust isn’t the Pro or anything right? I’ve heard people say that the T-6 is really loud. Is this as true as people make it out to be?
omalley
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omalley 12/7/2019 7:45am
12/7/2019 7:45am
omalley wrote:
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip. I...
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip.

I never rode it with the stock pipe, but from my previous Kawis, the PC typically added a bit of bottom and longer rev. The remap added more everywhere, got rid of popping and hot running (which was bad stock), and believe it or not, changed the tone of the bike. It might not mean anything in the grand scheme, but I’ve had several folks comment that my bike sounds different than anyone else’s, in a good way.

I have yet to hear an FMF exhaust on a 4-stroke that I like. They all sound like the packing is blown from day 1. Just my 02.
DawsonBMX54 wrote:
The exhaust isn’t the Pro or anything right? I’ve heard people say that the T-6 is really loud. Is this as true as people make it...
The exhaust isn’t the Pro or anything right? I’ve heard people say that the T-6 is really loud. Is this as true as people make it out to be?
I don’t feel it’s any louder than any other system. To me, it also has a deeper sound (partly after the remap), making it sound quieter in some ways.

It’s even quieter if you leave the insert in the tip, but that kills too much bottom for me as I like to ride taller gears.
DawsonBMX54 12/11/2019 6:15pm
12/11/2019 6:15pm
omalley wrote:
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip. I...
I have the T-6 on my ‘18, with a pump gas Tokyo Mods map in my ECU and the restrictor removed from the silencer tip.

I never rode it with the stock pipe, but from my previous Kawis, the PC typically added a bit of bottom and longer rev. The remap added more everywhere, got rid of popping and hot running (which was bad stock), and believe it or not, changed the tone of the bike. It might not mean anything in the grand scheme, but I’ve had several folks comment that my bike sounds different than anyone else’s, in a good way.

I have yet to hear an FMF exhaust on a 4-stroke that I like. They all sound like the packing is blown from day 1. Just my 02.
DawsonBMX54 wrote:
The exhaust isn’t the Pro or anything right? I’ve heard people say that the T-6 is really loud. Is this as true as people make it...
The exhaust isn’t the Pro or anything right? I’ve heard people say that the T-6 is really loud. Is this as true as people make it out to be?
omalley wrote:
I don’t feel it’s any louder than any other system. To me, it also has a deeper sound (partly after the remap), making it sound quieter...
I don’t feel it’s any louder than any other system. To me, it also has a deeper sound (partly after the remap), making it sound quieter in some ways.

It’s even quieter if you leave the insert in the tip, but that kills too much bottom for me as I like to ride taller gears.
So with the T6 you never have problems with noise checks and stuff? I ride one track local to me and they have a DB limit since the track is literally in someones backyard.
Moto Obsessed 12/11/2019 6:23pm
12/11/2019 6:23pm
FMF Powerbomb will give you more top end, whereas Megabomb will give it more grunt on the low to mid - just a FYI
lawson34
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lawson34 12/11/2019 6:24pm
12/11/2019 6:24pm
Love my fmf exhaust
I recommend a heat shield I'm constantly bumping into it
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T-Fish
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T-Fish 12/11/2019 6:47pm
12/11/2019 6:47pm
Do you want it for looks or sound? I assume performance is the least of your worries.
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lawson34
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lawson34 12/11/2019 7:54pm
12/11/2019 7:54pm Edited Date/Time 12/11/2019 7:56pm
T-Fish wrote:
Do you want it for looks or sound? I assume performance is the least of your worries.
Woke the whole power band up, midrange hit is second to none... yes I like the looks too
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T-Fish
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T-Fish 12/11/2019 8:03pm
12/11/2019 8:03pm
T-Fish wrote:
Do you want it for looks or sound? I assume performance is the least of your worries.
lawson34 wrote:
Woke the whole power band up, midrange hit is second to none... yes I like the looks too
I’m saying if the guy wants performance over looks or sound, the Vortex is the way to go over any exhaust.
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lawson34
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lawson34 12/11/2019 8:21pm
12/11/2019 8:21pm
T-Fish wrote:
Do you want it for looks or sound? I assume performance is the least of your worries.
lawson34 wrote:
Woke the whole power band up, midrange hit is second to none... yes I like the looks too
T-Fish wrote:
I’m saying if the guy wants performance over looks or sound, the Vortex is the way to go over any exhaust.
I agree, pretty much the same cost too
DawsonBMX54 12/12/2019 5:40am
12/12/2019 5:40am
Moto Obsessed wrote:
FMF Powerbomb will give you more top end, whereas Megabomb will give it more grunt on the low to mid - just a FYI
Yes I am aware about the different headers and their power delivery. The KX has more than enough low end grunt for me so I don’t need any more haha. I find it falls on its face a little in the higher RPM range.
ElliotB16
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ElliotB16 12/12/2019 11:54am
12/12/2019 11:54am
I’m running the t6 system with the aggressive coupler. Bottom end power is unreal and still revs high. Very loud tho
ThaRickestRick 1/13/2020 12:15am
1/13/2020 12:15am
I tend to use the system that is primarily tested around a specific manufacturer. Yosh is typically developed around Honda so I use Yosh on my Hondas and I use FMF on my Husky for the same reason. I think FMF and Yosh tend to be at the top of the exhaust game but I'm not a Kawi guy so I dont really know who has done the most R&D on those bikes but my guess would be FMF. Really its a trivial difference between the top 3-4 exhaust manufacturers and the real difference maker will be having it tuned for said system... cant really go wrong unless you but something thats garbage.

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