Riccardo

I can't understand what you mean?
What do you intend for "similar torque charateristics"?
It doesn't seems to me that stock curve ad "my" curve are so different.
Shape it's the same, whit a major gain above 7000 rpm (better flow?).
I have to state that i used "DIN" correction for my graphs, in honour of our german friends ,whereas you, as real american patriots , use "SAE" correction that gives around 2 hp less. That could explain why my numbers seems higher than your standards.
I guess I'll engage to use only SAE hp in further discussions!
Bye!

PS. Consider that english is not my mother language!

RCVTR

I always have difficulty with the curves presented in magazines. The vertical scale is always exaggerated. I have not been doing any conversions, just observing torque characteristics. The increased flow is surprising to me, but as I stated earlier, the ports are much smaller on the VTR than the RC51 and torque comparisons are similar to what you have presented. The VTR heads are a big part of what makes it such a fantastic street bike. I didn't like the modiifed RC51 I rode as much as I liked my VTR on the street. The RC51 is far better on a race track.

Don't get me started on the US system of measurements!
I mean, what better way to measure power than to compare it to the rate at which a standardized beast of burden can pull furrows in a standardized plot of soil, using a standardized farm implement.

I htink we just like the way it rolls off the tongue. It's not "power", it's "horsepower". Much better. "Torque" doesn't need modification. It's a good word by itself.
"Torque". I love that word.

Does anyone here have a foot long foot?

At least we don't measure weight by the number of stones it takes to tip the balance, like the brits.

And by the way your English is far better than my Italian. Or my Russian. I go to a restaurant and point and grunt. Then see what I get. And say "spesiba".

I get to go home today, then leave for Jackson Hole Wyoming, where men are men. Women, too.

Riccardo

It was surprising also for me when I saw dyno results!!!!

I've compared stock SH curve with my VTR and RC51 (SP1 and SP2 in EU) with WinPEP7. The shape is similar for all of them but, obviously, RC51 curve is higher than the stoc VTR one over 7000 rpm. Above those revs, my VTR pushes harder than stock and it tryes to catch the RC51 curve!!!

It's for this reason that I didn't upset heads. I've done a (good?) blueprinting work, trying to get rid of the imperfections of a massproduction engine!

I've rode an SP1, few years ago and I DID NOT like it, nor for the engine, nor for the handling. The engine it's too peaky but it didn't pushes so hard as I believed. The bike handles like a truck!

Well.....we have to admit that anglosaxon measurement system is......funny

That's true!!
Curiously, here in Italy, but I guess also in all Europe, the horsepower is the only brit unit commonly used. Cal it "HorsePower", "Cavallo Vapore". "Pferde Stärke" or whatever, but it sounds much better than KWatt!!!!

but I hate your "lbsfoot". It's greek for me!!!!!!!

I hope that my english is understandable.
I have some (big) problems with idiomatic phrases and terms, but I've been able to survive for 14 day in the USA!!!!!

Wow, very near to Yellowstone!!!!
I have to visit the park. I donì't know when...but I have to!!!!!!!!!!



Bye

RCVTR

Don't miss Grand Teton National Park, if you go. Take a hike and it will be a grand wildlife tour.

Regarding the RC51: A well sorted chassis is highly capable. Bob Hayashida's SP1 was the fastest in these parts. For a laptime comparison, I checked the laptimes in last year's AFM Formula Pacific (basically 1000CC superbike) class. Ken Hill won the last race of the season with a lap time of 1:51.9 on a Hayashida built '05 Fireblade. Jeff tigert had a best lap time of 1:50.7. Ken was turning 1:51s on Bob's SP1 in 2001. Rich Thorwaldsen won the Open Twins chamionship by running 1:53s. Bob turned a highly respectable best lap of 1:55.7. Not bad for a working guy.

In comparison, the best lap time in 600 Superbike last year was 1:53.6. 650 twins were running right at 2:00.

Mine will be well sorted, but If I can get down 2:05, I'll be very happy. Mostly, I'm going to have fun trying. Riding smooth and not ptiching the thing away.


I still have to question your dyno results. It's not about my porting is better than your porting. 120 HP was the output achieved by Moriwaki and the like with Stage 1 cams, oversized valves, decked and ported heads and full, tuned exhaust system. These things all have a cumulative effect to obtain that output. That my heads got that close with stock pistons and a 2 Bros exhaust tells me I wasn't too far off. I would expect very moderate gains with more polishing.

Something is missing. Have you overbored your block? (As we say in America, there's no replacement for displacement).

RCVTR

I forgot to mention that Ken Hill told Bob that the RC51 is still his favorite chassis among all the GSXRS and CBRs he's raced.

I'm going insane not having a bike to work on!!

Riccardo

RC 51 (SP1-2) is a very good base for a racer, but there is a lot of work to do on it to let it fast as a Ducati or a Japanese 4c literbike!

In regard to my bike, I really don't know what to add, except that it's not overbored nor a stroker.
Probably I've been very lucky!
I guess that we have to read my results from another point of view.
Do not consider the aboslute value of 119-120 hp, but lets point our attention on the gain Vs stock or light tuned curves. Is a gain of 14 Hp possible or "beliavable"?
Bye

RCVTR

Yes, and I need to apologize. I do not mean to sound like I am discrediting your work. I'm sure you have done a beautiful job and you are justifiably proud of it. A built VTR engine gets close to 70 ft-lbs (9.7 kgf-M). Your numbes are not unreasonable.

I enjoy the conversation. So much of what I do is in a vacuum. Not many enthusiasts in my neighborhood. Lots in Reno, but I don't get down there much. When I did my engines, I had to do the work with minimum impact on my home life. I went to Bob's to cut valve seats on a perfect powder day, because he had set aside the time to show me the technique. I'm pretty sure I have not heard the end of that at my house!

So, Cheers to a fellow enthusiast! And all the others on the sidelines. Hopefully, our conversation has added to the knowledge base out there. I'm sure there are others with more experience than me, that aren't sharing what they know. I just like to talk about it. And lately have been on standby, in a far-off country with nothing else to do.

Not so now. Skiing backcountry powder in the Tetons this week!!! Staying in little log cabin on the edge of the national park.

Oh and the RC51. I'm trying to cut some weight, and move the center of mass down and forward. The stock bike has too much rear weight bias. Steepening the head angle should lighten up the steering. I'm going to learn a lot from the development.

cheers,
Rand

RCVTR

One other thing - my comment about the torque characteristics being not similar. I had looked at the RUMI chart, not realizing yours was different. Sorry about that.

8541Hawk

Well in Ca the supplier for PVM is right here
http://www.ema-usa.com/wheels/wheels_PVM.shtml