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Discussion Starter #1
Does top end porting defeat the purpose of the powervalve? or will the powervalve always help with smoothness no matter what porting. Im running ct350pv with neils mid porting, it is unbelieveably smooth but id like it to pull more up top. Thought about switching to a 28cc dome(210-215psi). By no means is this a drag quad, just wanting to know at what point does a pv become pointless
 

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I would say that the powervalve never becomes pointless unless your in a strictly drag situation.
 

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I'm trying to think, but cant remember what pipe your running. You could switch to a higher revving pipe & get a little more top end.

Thats one of the sweet things about a P/V cylinder, you can port them for upper midrange or drag & then the valve will retain most of the bottom end.
If you go to a drag port on your cylinder, you will loose just a little bit of bottom end but not as much as a non P/V cylinder.
Neil
 

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a NON PV motor will more then likely always make more power, because you dont have any restrictions with the valve, however, the PV cyl with the PV blocked off is awesome, cause you have unlimited work area in exhaust port height. the biggest problem IMO with the PV cyl is not being able to make the exhaust wide. another probelm i have with PV, is if you dont know how to tune them, they are kinda useless...i knwo the tax and ct valve is better then the esr.... its all a combo really, pipe, timing, comression, squish, squish velocity, etc etc etc....te list goes on and on huh neil! :)
 

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a NON PV motor will more then likely always make more power, because you dont have any restrictions with the valve, however, the PV cyl with the PV blocked off is awesome, cause you have unlimited work area in exhaust port height. the biggest problem IMO with the PV cyl is not being able to make the exhaust wide. another probelm i have with PV, is if you dont know how to tune them, they are kinda useless...i knwo the tax and ct valve is better then the esr.... its all a combo really, pipe, timing, comression, squish, squish velocity, etc etc etc....te list goes on and on huh neil! :)
Yep, you said a mouth full thats for sure.
How does that go, million kazillion billion things that can be done, but you got to know what goes together for it to work right.

What you think about, if a Pro-x cylinder could be got with the oval exhaust port & then no PV machining done to the cylinder.
Neil
 

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that would be an awesome cyl.....and i know some things about what you are trying to say! LOL
 

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Discussion Starter #7
im running a sparks tt. so i figure i will wait until i need a bore and have you do some more porting neil. So its easier for you. i might just go ahead and buy that dome from you.
By the way what do you guys recommend for a pipe. i believe i have a pretty good combo
 

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im running a sparks tt. so i figure i will wait until i need a bore and have you do some more porting neil. So its easier for you. i might just go ahead and buy that dome from you.
By the way what do you guys recommend for a pipe. i believe i have a pretty good combo

Lets try something just as a test.

I know this test will change how the engine runs but, lets see if its as much as what your wanting.

Go to an auto performance shop & buy a roll of the high temp exhaust wrap, 1 1/2" or 2" wide will do & it dont need to be the higest priced either.
Get some safty wire as well to hold the wraping on.
Now, take the high temp wrap & start wraping it around the pipe.
Start wraping it on the pipe where it comes out of the frame in the front where you can get to it easy & keep on wrapping it till you get to the place where the stinger welds on to the tail end of the cone part.
No need to wrap the stinger pipe cause it wont change anything.
You can, just wrap a short piece of the pipe say 8"s or so, go try the bike out, come back & wrap some more & see what that changes.
For the test to work right though, engine & pipe & all need to be up to operating temps or else you wont be able to tell anything.
This is a simple test to see if a different pipe is what your needing.
Long built pipes are for bottom end pull engines & real short pipes are for high rpm pull.


Hey, I dont have no magic carpet or can do tricks like you see on tv, but ol big daddys been around a good while I took notes of everything he seen worked. :p
Neil
 

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Discussion Starter #10
should this difference be an improvement? say i like how the pipe feels and pulls when tape is around it, how do you know what pipe to go with.... im sure you have tricks for this too.

neil what pipes do you have the most success with on this type of motor
 

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should this difference be an improvement? say i like how the pipe feels and pulls when tape is around it, how do you know what pipe to go with.... im sure you have tricks for this too.

neil what pipes do you have the most success with on this type of motor
When you wrap just a small section of the pipe, pay close attention to how the bike feels, how it pulls in the upper gears. Take a notice at, as its pulling through the rpms where it feels like the power is dropping off.
It will take your feelings, of the bike & then your ears hearing what the engine is doing to be able to figure out the test & then tell if its changing anything.
I bet you didnt know you was fixxin to go to school with this testing. In the end, I'll find out how good a rider you are or level.
Realy its not that big a deal, you can handle it.
Neil
 

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that would be an awesome cyl.....and i know some things about what you are trying to say! LOL
Whuee boy, guess what I found out about a oval port cylinder today, MIGHT JUST BE ABLE TO GET ONE, :D :p & aint many people that can do that.
Neil
 

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If you are wanting a little more top end, you ought to try the ESR trx5 standard or Center mount. The center mount is better for big bores. I've heard that the CPI big bore pipe is really good. You could also try the CT powervalve pipe.
 

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well Neil ported my powervalve cylinder awhile back & I can honestly say it had noticeable diference & is still smooth as always just better bottom to mid performance yet still pulls on top ,& the Cr ignition obviously helped the all around performance I would say the cylinder has great type power
 

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Discussion Starter #15
any of you guys running a smaller dome on your pv or big bore? i think i will notice quite a difference going from 180psi to 215, especially if i get a little more porting done up top.
 

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I also increased my comp. from 180 to 210 but haven't tried it yet cause of weather.
 

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any of you guys running a smaller dome on your pv or big bore? i think i will notice quite a difference going from 180psi to 215, especially if i get a little more porting done up top.
"smaller dome " ??? ..do you mean the race gas dome ?
 
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