KDXRIDER.NET

ok, sorry to burst everyone's bubble with my bit cracked out ideas...but i learned some intesting facts. Ok, first off, has anbody ever dynoed their KDX with a FMF or pro circuit exaust system on it...? Because all the hyp may be for absolutly nothin...why? Because unless the motor has been ported and polished...your not doing that much...heres why:

Even tho an exaust system helps the motor breath better, the small casting residue left in the intake and exaust ports are just big ehough to cause a fuss in the process that it renders the new pipe ineffective...Not totally but it does do a number on the negitive side...think of it like those dudes in their honda civics with their fancy fart mufflers...

yea they sounds good, but if u dont Port N Polish the engine to allow the flow of air and fuel to go evevn faster, then you arent getting the full basket'n'robbins...so all im saying is, next time u do a head job, think of polishin you prots and getting ridd of the over cast...this helpsa bunch FROM WHAT I HEAR....

i will definatly try it and see what happens...i could be dead wrong, but ive herd a good Port n Polish goes farther then a new exaust system when compared...any comments on this???

Polish=BAD!

Cleaning up the casting is fine and watch for flow but never polish the intake side! You need turbulance to mix the fuel and air to get a good burn... or all your going to have is a spoo factory.

Flow is important and that's why the proper reeds help out. There are 3 reed types for the KDX that help. The DFII and DFIII and the Boysen power reeds (607's).

Seat of the pants will tell you different on you pipe theory. Regardless of how restricted it is stock... the FMF pipes make a huge difference from stock.

Re: Have you ever...

Yep.

Not me personally, but Ron and Dan have lots of hours on Ron's dyno and Dan's KDX.

Re: Any comments?

Yeah. DON'T DO IT!! (the polish part)

Inda has it right, is correct, and otherwise is of the required (right and correct) thinking.

Listen to the man.


In other words, 'What a cracked out idea!!'

BTW...the 'port and polish' idea has been around for a brazillion years. It was wrong when it began and it's wrong now. It takes a person knowing what they're doing to port anything...4 or 2-stroke. Give a maroon an angle grinder and some sandpaper and he'll ruin most anything.

BTW#2...another way to pronounce 'pah-lish' is 'poe-lish'.

Get it?

Of course you do!

You're going to have to try a bit harder to burst this bubble.

I "tested" my rev pipe that I received for my newly acquired 220 (I say tested because I need to replace the stock piston first but I couldn't wait). There's absolutely no hype when I say that it perked the 220 up big time - all around, but most noticeably it would seem that I have some top end now. Don't know about the polishing, Inda and CC seem like they do, but I have to disagree with the "pipe is hype" comment.

'Seem' like?

Truth is...it's the truth!

ANYone that uses the term 'port and polish' to mean anything other than what you should never do I'm afraid is someone that has a very wrong idea.

I still wonder what would happen if I were to take off QuailChaser's PC Plat II torque pipe and trade it with a suitable rev pipe on my R-B'ed 2003 220R.

As is known, either a torque pipe or a rev pipe are recommended to replace the stocker in the 200, while the 220 doesn't benefit much from a torque pipe but is lit on fire by a rev pipe (edited to correct my forgetfulness).

I wonder if it'd be worth the $200+ to get a new rev pipe?

Of course, I'd love to see dyno data for proof. Anyone want to send me a loaner rev pipe so I can have it dynoed?

Then I'll port and polish it.

Rick

Well, don't ask ME.

I run a rev (-30) on my 200, so I'm obviously out of the loop.

..or I AM looped.

Sumthin' like that.

Maybe I just didn't realize what is known.

AZRickD wrote:

I wonder if it'd be worth the $200+ to get a new rev pipe?

Worth every penny

I suppose I could sell my torque pipe.

I sure wish I could see some dyno data. How much low-end would I gain if I removed the torque pipe? Does anyone know how much upper end I would gain (torque, hp, revs) when comparing the torque pipe to the rev pipe?

Rick

I've got dyno run charts.

I wonder if it would be worth $200+ to see them....

Well...I HAD them. I'll see if the data is still readable.

OSs have changed since then...

Re: 'How much low-end would I gain if I removed the torque pipe?'

Huh? Do you mean how much would you LOSE?

It's not the numbers that matter anyway. The general consensus (has been for years) is the -30 won't lose you anything noticeable vs: stock on the bottom and greatly improve the top. Comparing it to a -35? You will lose bottom end pull.

It's all a matter of what you want. The 220 is strong on the bottom anyway. It generally isn't considered to need help there. That's why the general consensus from 220 riders is to use the -30.

If bottom end is what you want, the -35 is the pipe to use.

Put the -35 together with with porting of the 220 and you are going to have a top-end anemic ride.

If top-end is what you want AND you want a KDX, you should'a bought a 200.

Does the top-end of a KDX200 match a punkin 200? No.

It's all relative.

If it'll make you happy to see a little squiggly line track a bit different than some other little squiggly line...I'll post the KDX dyno info if I can get it off the media.

Yep! What a guy! I'll even do it in ADVANCE of receiving $200! + even!!

When was the last time top end got you to the top a a snotty hill??
Look for gains in USABLE POWER. Low & Mids are what you will use most of the time. The -30 on a 220 makes a noticable difference as well as the addition of a DF3 & RB Head & Carb Mods. So is it worth the $200....YES

Oh yeah all of this talk about getting head jobs & getting your ports polished is causing me to think of other activities... So STOP, I'm at work still

When was the last time bottom end kept you ahead of a 250??

GH... if your thinkin' of getting your PORT polished... you must live an Massachusetts!

I've not ridden my 220 enough with the new -30 pipe to give a detailed analysis. But I don't notice bottom end loss; rather, I picked up power all the way 'round . And I notice a whole lot more from midrange to top end. Maybe one difference is that's it's colder now and since my jetting was on the rich side the bike runs stronger under a leaner condition (?).

To quantify the top end I seemed to have picked up, it doesn't sing like a 125 or anything but where I was shifting before, it's still pulling, and pulling nicely!

The rev pipe was a terrific investment, and the only other mod I've made was some holes drilled into the airbox lid.

Oh, BTW: I've heard that there's supposed to be a stamp next to the upper tang with "K30" or "K35", but I've looked all around and there is no such thing on this pipe. Did they stop stamping them? I know!! Maybe I have a rare pipe with no stamp, worth thousands on Ebay!!!

Think that's something... I have one stamped wrong! You know those Calf folks smoke lots of weed!

Indawoods wrote:GH... if your thinkin' of getting your PORT polished... you must live an Massachusetts!

Suishhhhhhhhhhhh
Don't tell anyone

Indawoods wrote:Think that's something... I have one stamped wrong! You know those Calf folks smoke lots of weed!

Come to think of it, my pipe just might've had a slight odor to it - 'wonder how they "test" the pipes? Redefines the whole "dyno" thing, huh

Motorhead....You're thinking 4-stroke. To think 2-stroke complete your doctorate in physics w/ an undergrad in mechanical engineering. Then go smoke some reefer w/ the FMF guys to put it all to good use.

so dont DONT prot and polish the INTAKE side, Clean the cast sure, but no polish...But can i clean and polish the hell outta the exaust port? that woud help breathing no?

CC,

I look forward to your charts comparing a rev pipe with a torque pipe. All the comparisons I've seen have been with a stock pipe.

Rick