Kawi2strokes.com Forum

As I have said before I helped a new friend by rebuilding his H2 last winter and we have been able to ride together a number of times, and we have swapped bikes back and forth. I have found this to be enlightening comparing one to another. As my H2 experience is very limited.

His H2 has Factory pipes and UNI filters and mine has Spec II pipes and UNIs with my patented velocity stacks. His has correct as possible jetting and mine has an Ivan's jet kit.

When you compare, his is quite a bit faster, the front end is coming up in the lower gears anytime you give it a reason to and mine though quick is not so wheelie happy.

They both move down the road good at highway speeds but mine takes more throttle to speed up between 4500 and 6000.

Mine pulls way harder in the 2500 to 3500 speeds.

His is faster, it is obvious from the butt dyno.



Until we ran them off ......., mine pulled his 4-5 bike lengths when we kept them on the boil.

Obviously his has more mid-range and mine has more top end, by quite a bit.

But as the saying goes "there is no free lunch" the top end comes with the expense of mid-range.

If it ever cools down we will trade pipes and verify the difference is the pipes.

I also have a set of stock pipes out in the shed and I will try those somewhere down the road.

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Using a poorly conceived idea along with bad mechanical practice is not an upgrade but rather a recipe for disaster.

Very good stuff and just a thought. I would venture that if you did this same test on an RD 400 with the brand SpecII and Factory pipes that you would get very similar results. Your experience appears to be in the "nature" of the designs.

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There are 3 kinds of people in this world. The kind that can count and the kind that can't.

I like this post Joe - keep it coming with comparisons.

bb

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This is true. Where I grew up the hills were so steep and long, when your ball rolled down the hill you just said "screw it"...

FPP are top end pipes, especially with any kind of porting. And rev to the moon.

One of my oldest reed stories is my buddy Ron (holysmoke) had a ported 750 with FPP pipes. (he bought that way) There was a decent "hill" to get out of his sunken driveway, and he couldn't get the bike up the grade without smoking up the clutch and reving the hell out of the motor.

Ron called me and asked if my reed conversion would help. And I said it "should". So I did the conversion for him and he then could "ride" out of his driveway. Ron also eventually went to Spec II pipes also, as he liked to rev out the motor and with the FPPs would go past 11,000 too quick.

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Twist the throttle, tilt the horizon, and have a great time. What triples are all about...........

Odd that you say his is quite a bit faster and pulls the front wheel more easily yet yours beats it in a drag race; not sure how to read that

I can offer that my H2 with pods was much weaker in the bottom end with FPP's compared to Denco's
I agree with John that the FPP's also reved more freely but I did not feel that they were superior in any way other than in a pure WFO throttle condition; they've been hanging in the garage ever since the Denco's were found

The FPP's are considerably quieter presumably due to their clamp on silencer
Daren told me to keep them as he felt they worked much better with reeds than the Denco's would

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There are only two types of motor sport racing:
Nitro and everything else
(Sometimes referred to as fast and slow)

I think the deal is that the belly on the FPPs are longer and they plainly have more between 4K and 6K, at 6K the Spec IIs make the H2 come "on" sort of on the lines of a typical H1.

Notice when I said how much faster mine is, was when we kept them on the boil. My Spec IIs on my H1A are quite a bit like the H2 as far as powerband; soft aprox. 4K-6K and then all hell breaks loose.

I have seen dyno curves for Spec IIs and they will pull 15 more HP than a stock H2 but loose nearly that much at 5K.

I think because of the noticeably longer belly section the FPP have more in the middle, so far the pipiest pipes I have ridden on an H2 are the Spec IIs.

Now if you keep it above 6K they are very fast.

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Using a poorly conceived idea along with bad mechanical practice is not an upgrade but rather a recipe for disaster.

I always keep it above 6K, that's where the fun is!

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We don't need no stinkin' Cams!

I find these results interesting.

I would have thought that the SpecII's would have had better midrange than the FPP's, as I always thought that they were a "knock-off" of Denco's.


I look forward to seeing the results after you swap pipes.

My H2 with 34s and FPPS and a relatively mild port job ( basically a clean up and intakes port matched for the 34s+ heads corrected and cylinders decked) pulls like a tractor down low and will wheelie hard in the 1st 2 gears. With the Haase piloting, will pick it up in 3rd. It will however I am sure, rev till it blows. I had Spec IIs on it before and I like the FPPS much better overall. Just my .02 cents. A lot of you have ridden it. It may be a combination of tuning, light weight (408 wet) and the 16 inch rear wheel, though the gearing is very close to stock. At any rate for me FPPS are the pipe I like the best.

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I Love the Smell of Blue Marble in the Morning!!!
Tim Steele in Front Royal, VA
Home of the Phoenix Project
Stay in it when it comes on the pipe, no need to be scared...

We just got home from 2400+ mile Valkyire ride..

I made some stainless exhaust spigots that are 1.00" longer than the Spec IIs to see if added header length would boost the mid-range, the answer is minimal. As they say "Busted!"

I did lean the pilot and the main, she runs a lot snappier, but I am right on the verge of ping city.

It has been a very busy summer and maybe next month I will be able to do some pipe swapping. Remember there is a lot more summer in September than June.

I learned that the better a pipe works "on the pipe" the worse it works "off the pipe"

The Spec IIs really pull hard "on the pipe" but the mid-range is indicative of the above truth.

Adding an inch to the header isn't enough.

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Using a poorly conceived idea along with bad mechanical practice is not an upgrade but rather a recipe for disaster.