Pro Circuit 450 head modification

kx450sr
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kx450sr
Can anyone explain what PC head mods feel like? Or head mods in general? I've read/heard that sometimes they feel on/off. I'm looking at Twisted and PC since both of those shops have a lot of r&d on my bikes.

Yes I don't need more power (if it gains any) I know that but I'm looking to improve the bike wherever I can, thanks in advance.
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kb228
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kb228 2/5/2021 2:55pm
2/5/2021 2:55pm
I believe they tune the heads for the power delivery you want. Some may want explosive power and some want smooth power
captmoto
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captmoto 2/5/2021 5:53pm
2/5/2021 5:53pm
kx450sr wrote:
Can anyone explain what PC head mods feel like? Or head mods in general? I've read/heard that sometimes they feel on/off. I'm looking at Twisted and...
Can anyone explain what PC head mods feel like? Or head mods in general? I've read/heard that sometimes they feel on/off. I'm looking at Twisted and PC since both of those shops have a lot of r&d on my bikes.

Yes I don't need more power (if it gains any) I know that but I'm looking to improve the bike wherever I can, thanks in advance.
Have you had your ECU remapped or are you running a Vortex. That is the best bang for your buck in mods.
kx450sr
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kx450sr 2/5/2021 6:20pm
2/5/2021 6:20pm
captmoto wrote:
Have you had your ECU remapped or are you running a Vortex. That is the best bang for your buck in mods.
All stock before teardown, I plan on going with a Vortex from TD but I'm getting the valve seats cut from PC so I figured what the hell let's do their head mods while we're at it you know?
Drail24
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Drail24 2/6/2021 6:12am
2/6/2021 6:12am
Head mods can definitely make a bike "feel" different. Typical head mods involve modifying and reshaping the intake and exhaust ports (and/or valve seats) to change and improve the airflow through the head. If you just want to make more horsepower, you can usually grind and reshape the ports so that they are bigger and flow more air at higher rpm's. The downside to this is that it doesn't flow air as efficiently at the lower rpm's, which leads to a "lazy" feeling at lower rpm's and when rolling on the throttle, but as rpm's increase, the power ramps up quickly giving a surging feeling. As most will agree, this type of power makes a bike tiring to ride for long periods, due to how aggressively the power is being applied. The trend by the manufacturers for the past several years has been to produce broad, smooth power...not as much peak power. Although it doesn't "feel" as fast, it is much easier to ride for longer periods, which usually translates to better lap times for most people.

A "good" head mod for most people will be slightly adjusting the ports shape and size, using a better multi-angle valve job, and possibly making small changes to the combustion chamber to increase the efficiency of the head providing an improvement in the overall power curve.. not just one area. Maybe some gains can be made down low without losing any power up top, or vice-versa. Easier said than done, which is where the R&D comes into play. How much of a difference will a head mod alone make to a newer bike and can you "feel" it? Hard to say, but typically when you combine that with a cam and ignition tuning, exhaust, etc. the overall package can make for a noticeable change.
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wheeler727
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wheeler727 2/6/2021 10:42am
2/6/2021 10:42am
captmoto wrote:
Have you had your ECU remapped or are you running a Vortex. That is the best bang for your buck in mods.
kx450sr wrote:
All stock before teardown, I plan on going with a Vortex from TD but I'm getting the valve seats cut from PC so I figured what...
All stock before teardown, I plan on going with a Vortex from TD but I'm getting the valve seats cut from PC so I figured what the hell let's do their head mods while we're at it you know?
Take the head to Jaime at TD if you’re have the vortex done. He did a great job on my KTM, decked the head, cut the seats and CNC port.
1
kx450sr
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kx450sr 2/6/2021 10:52am
2/6/2021 10:52am
Drail24 wrote:
Head mods can definitely make a bike "feel" different. Typical head mods involve modifying and reshaping the intake and exhaust ports (and/or valve seats) to change...
Head mods can definitely make a bike "feel" different. Typical head mods involve modifying and reshaping the intake and exhaust ports (and/or valve seats) to change and improve the airflow through the head. If you just want to make more horsepower, you can usually grind and reshape the ports so that they are bigger and flow more air at higher rpm's. The downside to this is that it doesn't flow air as efficiently at the lower rpm's, which leads to a "lazy" feeling at lower rpm's and when rolling on the throttle, but as rpm's increase, the power ramps up quickly giving a surging feeling. As most will agree, this type of power makes a bike tiring to ride for long periods, due to how aggressively the power is being applied. The trend by the manufacturers for the past several years has been to produce broad, smooth power...not as much peak power. Although it doesn't "feel" as fast, it is much easier to ride for longer periods, which usually translates to better lap times for most people.

A "good" head mod for most people will be slightly adjusting the ports shape and size, using a better multi-angle valve job, and possibly making small changes to the combustion chamber to increase the efficiency of the head providing an improvement in the overall power curve.. not just one area. Maybe some gains can be made down low without losing any power up top, or vice-versa. Easier said than done, which is where the R&D comes into play. How much of a difference will a head mod alone make to a newer bike and can you "feel" it? Hard to say, but typically when you combine that with a cam and ignition tuning, exhaust, etc. the overall package can make for a noticeable change.
Thank you for sharing, that was very valuable information to me
adam8781
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adam8781 2/8/2021 5:40pm
2/8/2021 5:40pm
twisted
proven
pc
c4mx
xpr

all make great stuff, if it was me id talk to frenchie at c4mx, hes huge on making insanely fast easy to ride setups
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