KDX 220: Rev vs Torque Pipe. A case study

[2001kdx]

Like mike said, there's no need for an aftermarket silencer. The only reason I have one is because it was there when I bought it.

[220trailrider]

honestly i do have all new gaskets inside my engine and a wiseco piston, but, ur saying i can keep the stock silencer and it will be alright? Also, how much are we talking about for carb mods, i have heard a lot of great things about them.

[220trailrider]

is there any altercation i can do to the stocker?? i have a good friend that welds

[scheckaet]

keep the stock silencer stock. Runs good.
Carb mod: http://www.rb-designs.com/

[UFS207]

Sorry to dig this thread up but was any more testing done to compare the PCII to the Gnarly Rev pipe? I've got a rev pipe on my mostly stock (motor-wise) 220, was there when I bought the bike in late '04. The description of the PCII's type of power has me really curious is to how my 220 would react.

I'm real close to performing a $200-$250 experiment. If so I'll see if any of the local shops with dynos will run bikes and get some real numbers for others. Somebody talk me out of it and tell me what a POS the PCII is.

[2001kdx]

I believe the PC2 is more of a torque & bottom end pipe.

They way I've always senn it, the fmf pipes went like this:

FMF Rev = 85% Upper Mid and High gains, 15% lower rpm gains. The opposite for the woods pipe.

Then My impressions of the Pro Circuit equivalents were closer to 50/50 I.E the PC2 being more like 70% Low-mid and 30% mid-high.

PC's have always been more of an overall power gain.

[hart125]

the big deal here is comparing the pc2 to the fmf. the pc2 is the new tech pipe and the platinum 1 is not made anymore. pc did their homework and the pc platinum2 is the answer! I have had the fmf woods, desert, platinum and platinum2. the platinum has a little better top end but the platinum2 is the best balance!

[2001kdx]

An old thread... Got a PC2 now :)

[the trail rider]

personally for me I have not tried a pcII but the rev pipe on my 220 woke it right up. as someone said before without the carb adjusted fairly perfect it does not perform as well on the bottom end. with the pipe you lose some low end response but the power is still there and everything thing above a extreme low end has good power. I am running the stock motor stock carb, I have a vfIII with rev pipe and turbine core II silencer my bike feels like it has 150% the power it did over stock. It will be interesting to see what rb carb mod and head mod does to the 220 along with these mods since ron is just right across the river from me I can take it directly to him and he can put in a dek needle and do the head and carb at the same time. and I will finally put in the weisco piston as I have not yet and I know that I need to. good thread guys. and It is good to be back!

[Jeb]

personally for me I have not tried a pcII but the rev pipe on my 220 woke it right up. as someone said before without the carb adjusted fairly perfect it does not perform as well on the bottom end. with the pipe you lose some low end response but the power is still there and everything thing above a extreme low end has good power. I am running the stock motor stock carb, I have a vfIII with rev pipe and turbine core II silencer my bike feels like it has 150% the power it did over stock. It will be interesting to see what rb carb mod and head mod does to the 220 along with these mods since ron is just right across the river from me I can take it directly to him and he can put in a dek needle and do the head and carb at the same time. and I will finally put in the weisco piston as I have not yet and I know that I need to. good thread guys. and It is good to be back!

If you liked what the rev pipe did for you, you're gonna enjoy the benefits of Ron's modifications to your 220. I went even a little further and had an extra head I picked up on ebay modified for race gas. All told, it's a different motor . . . and it's all good!!

[bmase]

Since I have run three different pipes on my 03 stock 220, I think I can reinforce what I am seeing written about the PC pipe. However, I found a Pro Circuit Works pipe ($45 bucks to boot brand new), so I can't compare it to the PCII. I understand the PC Works pipe runs more like a hybrid of the rev pipe and the PCII. When comparing it to the FMF rev pipe, I can do more with the PC pipe. It's just a blast to ride with that pipe. However hard I twist the throttle is exactly what it produces. The FMF pipe makes a lot of noise, and I can wring out the gears, but I don't find the bike rips any more with it all around. Also, it also does not seem to hook up as well. Plus, it seemed to spooge excessively with the FMF pipe. I rode today with Amsoil in the tank for the first time, and between that and the Works pipe, it was a little scary. I could go up a hill as slow as I wanted, or just blast off the top like a KX250. I'm second guessing if I need to be RB'd. How fast is fast enough, and it pushes the KDX's suspension to the limit. As far as the stock pipe, either pipe is an improvement in jetting and performance over stock. I found it unpredictable. However, it ran much better with the jetting on the lean side. I run that same jetting now, CEK 2nd from top, 142/40. Pick up an older PC pipe if you can find one left at a dealer or on e-bay. Just don't look for my pipe to be listed there, that's for sure. The FMF pipe with a total of one hour will most likely be sold as the loser of this test. My only negative about the PC Works pipe is that I have to short shift alot. Any recommendations for gearing changes to solve that problem?

[plb]

«Come on now, keeping that rev will teach you clutch control and make you better.»

Yes, I agree.

I rode 2 years my 220 with a Woods pipe in heavy section at low speed (rocks, trees, woods, hard hills to climb) and since I have my Rev, it's hard to ride so easily (the Woods is like an autoclutch... you never stall, the motor never dead, is always alive).

BUT, I have so much Top End and so much punch with the Rev, I have to be a better rider in slow-speed with the Rev, BUT I have an upgrade (top rev) that I NEVER have with the Woods.

KDX220 FMF =
Beginner and intermediate rider = Woods/Torque
Intermediate an pro rider = Desert/Rev

For Pro Circuit, I don't know... never try. A friend saids it gives a little of everything (bottom, mid-range and top).

[bmase]

Yep, it is all about where you ride, but I have a feeling the PC Works pipe

is a little different than the FMF Woods pipe or PCII. I love the throttle

control I have, and it seems to be the best of both worlds. Like I said,

the only drawback is that it produces power so quickly, that I run out of

gear before I am ready to shift. I don't have the skill to shift when I am

trying to keep my butt from hitting the ground. In fact, I never saw my

fender in front of my face nearly as much with the rev pipe. This thing

pulls the front end like a MX bike. It's got that much zip and pull. Trust

me, find one of these PCI or Works pipes and give it a try, you won't be

disappointed. I have read very few threads of anyone using a Works

pipe. In fact, it's the only one I have seen in a bike shop, and it does not

hurt that I only paid $45 for a new one. For that price, I could not resist

giving it a try, glad I did. For the record, it fits my power core II better

than the rev pipe did.[/img]

[Wudscrasher]

I'll throw a curveball to y'all:

What's your final drive ratio?

It does have an affect on your impressions of 'boost', 'top speed', 'awakening', etc., so, how many teeth do you have. What y'all have said means zilch to me, as I am probably running a ratio unlike any of you, especially you open, desert guys.

For instance, '00 220R, VFIII, FMF 'Woods' pipe, FMF TCII 'Q' (for repacking/quiet purposes) on mine. 13T front, 51T rear sprocket (stock is 47). Do I have torque? , but I can also run super-tight, rocky, Colorado singletrack in 3rd & 4th gear, using 2nd rarely and 1st only to get a boost up ledges. Top speed? Try 65 mph WFO in 6th. I'll never NEED 65 miles an hour where I ride. If you should ever attempt the Red Trail or 5 Miles of Hell in Utah with your 'top-end' pipe and stock gearing, you'll burn your clutch up. The open sand washes were a dream to cruise in 6th at 45-50 mph, too! I tested for awhile to find the setup that works for ME. There's not one combination of mods/pipe/drive ratio that fits everybody. My suggestion, look at what you intend on riding, and set up accordingly. My apologies to Jeff Fredette, but I am not him, therefore, I'll stick with my Woody on my 220, because I am pleased with my setup, and I think it's perfect. YMMV, and that's OK.

-- C.J.

BTW, a louder pipe doesn't mean it's better. Keep quiet, guys. I want my kids to be able to ride in the woods someday.

[bmase]

Thanks for the info Wudscrasher, I will take any advice on this subject. I feel like I have a handle on making changes to the motor as far as changing it for different weather, etc.

However, I have not tackled any changes in the drive ratio. I ride mostly hilly, rocky terrain in Missouri. Wintertime is pretty muddy. Summer is hot with a lot of hard stuff.

Like I said, I find myself shortshifting with the PC Works pipe vs. the rev pipe. It's perfect in everyother way, except this can be annoying. If I knew what each change in the sprocket made, I'm sure I could dial it in like I have with the motor and carb. My mind seems to reason well when it comes to anything mechanical. I obviously don't want to go out and buy five different combos to gain something I'm not sure I will gain.

[Jeb]

. . . My mind seems to reason well when it comes to anything mechanical. I obviously don't want to go out and buy five different combos to gain something I'm not sure I will gain . . .

You mentioned you wanted to gear differently to eliminate short-shifting . . .

Why not start out with a 14-tooth C/S? Even for an expensive unit you're talking less than $20, half that if you go with a cheaper brand. You can change things based on what you perceive your gain was/wasn't and minimize your cost and time (meaning that you change your rear sprocket one time as well, but you'll have an idea what to get). 'Shouldn't take five different combos since you're mechanically inclined. I'm not mechanically-inclined, but after changing to a 12t sprocket (I wanted to gear shorter like Woodscrasher) I decided to get a 45-tooth rear based on saddle time and Indawoods' handy-dandy ratio chart. (Look under Drive Ratio forum, self-explanatory).

[motorhed220]

im definatly in wudzcrushers sitch....Ive goit 52 rear and 13 front...stock pipe for now....My top speed is horrid now...its like i dont have 5 and 6th gears for top end no more...mind you my torque is over the top, and the bike rules the holeshot nooooo problem what so ever.

Anyhow...i was wpondering, if i put a Gnarly rev on, and mabye a powercoreII, would taht bring my top end up to what it was before the 52 tooth reaer sprocket? And thus would i keep the bottom end???

If thats the case then ill have a tractor for a bike!!! lol
And on top of all this....how much of a loud and sound change does the pipe give the bike...i want it to sound like a 2 stroke MX bike...not an ACTUAL tractor...

Thanx ya'll!

[NoBs]

Somebody probably put an extra magnet on your rotor.

89 mph is certainly possible on the KDX... find a long steep mountain, kick it in neutral and tuck.. other than that, not so much..

[Chuck78]

Somebody probably put an extra magnet on your rotor.

89 mph is certainly possible on the KDX... find a long steep mountain, kick it in neutral and tuck.. other than that, not so much..

...18 years later,
an old thread is unearthed!

With stock gearing, my KDX220 stock + Gnarly Desert pipe topped out at 87mph according to the Trail Tech computer.

On a 220, the Gnarly Woods torque pipe beats out the Gnarly Desert rev pipe in the woods for smoothness and torque all around, if the 220 has an RB'd head or similar, & an RB 36mm PWK 35, but the Gnarly Desert is the faster pipe in the wide open and non-technical trails still.

The Pro Circuit Platinum 2 pipe, contrary to what someone said in 2007 on this thread, is a Torque AND Rev pipe. It beats both pipes FMF produces, but it does give a SIGNIFICANT mid-range surge that neither of the FMF pipes can match, making it a bit touchy due to the substantially powerful mid-range it produces. It makes useable power up to about 300 RPM short of where the Gnarly Desert drops off,
***As tthe Gnarly Desert rev pipe is quite a mismatch for the 220's porting**** Yes, the Desert rev pipe WILL "rev out" way higher by 800 RPM or so, BUT... It does so well beyond the point where you should have shifted to stay in the peak power - as the gearbox ratio spread is designed to do so.

I own two 220's with PWK, Lectron 34mm, Lectron Billetron Pro Series, RB heads, Fredette head, stock heads, soon to be KDX220SR heads, 4 Pro Circuit Platinum 2 pipes, 2 FMF Gnarly Desert pipes, & one FMF Gnarly Woods pipe.
I've got two friends with 220's with Gnarly Woods pipes - 1 is Fredette ported / Fredette head shaved / Fredette bored carb, the other is cleaned up DIY basic porting with an RB head and RB carb. They both are very powerful, but the RB'd engine absolutely screams....

There is definitely higher power to be had on a 220 with the Pro Circuit Platinum 2 and Gnarly Desert rev pipes vs the Gnarly Woods torque pipe, but the Gnarly Woods torque pipe still is highly beneficial for technical terrain and tighter woods riding, making a very smooth torquey power curve and being a nearly unstallable tractor, that's not hurting for power.

The fully RB'd Gnarly Woods pipe 220 has a wall full of trophies to prove it, and videos of pulling holeshots against modern 450's woods racing...

The Gnarly Desert is somewhat smooth, but lacks in torque, and even with the 220's torquey porting, the 220 + Gnarly Desert pipe makes "just enough" low end torque while making more peak power and being able to rev almost to the moon but as I said, at that point you should have shifted 1000rpm prior.



Unfortunately, the Pro Circuit Platinum 2 only gets produced in batches of 50 every several years when enough people request them for backorder. I really feel the PC Platinum 2 is the best match by a longshot, for the KDX220... I be trying out a slightly modified KDX220SR head (tighter squish like an RB, & a very wide squish band for more torque) with the Pro Circuit Platinum 2 next season. I may end up dialing back the wide squish closer to an RB head spec but still wider, but I'm eager to see the results. I'm pretty certain they will be great, and with luck, filling in the power below the strong mid-range surge of the Pro Circuit Platinum 2 pipe