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RPM's

Started by JoDuc, June 02, 2008, 06:06:37 PM

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JoDuc

So, if I wanna 'get on it' and open her up....

I remember seeing somewhere that after 7,500 rpm's I begin to lose power. Is that the case on a S2R1K? How high should I rev my rpm's for max power? IE - best shifting points....  Do I even wanna be up near 8, 9 and 10k in rpm's?  I don't know anything about dyno charts, is that what they are for?

SolidSnake3035

I would think you'd shift just about at redline, but I'm not sure... and it most likely differs between gears.
Speed is always relative.

Slide Panda

Each bike power plant's a little different.  2v vs 4v - EFI vs. Carb.  A well tuned engine will be making peak power at 80-90% of their redline/rev limiter.  Yeah it'll start to drop off a bit after that point, but it's not something dramatic.

Dyno(mometer) charts are the result of running the bike on a device that can read the horsepower and torque being put out at  a given RPM, they will also sample the CO of the exhuast  to help the tech fine tume the Fuel/Air Mix.  Yeah a Dyno chart would give you a concrete number of where you hit max power, thus giving your a shift point.

An no, it won't vary from gear to gear.  Max power generated by the engine isn't directly effected by gearring

But, unless you're a racer and need to worry about keeping in the optimal power range.. you needent worry that much.  Just take it out, give it a few hard passes and see how it feels.. and just go ride!
-Throttle's on the right, so are the brakes.  Good luck.
- '00 M900S with all the farkles
- '08 KTM 690 StupidMoto
- '07 Triumph 675 Track bike.

johnster

#3
For me, rather than paying attention to dyno charts + the tach and whatnot, I find it easier to just say to myself "OK...The bike seems to pull harder when the engine's making that noise, versus this noise, where it falls off a little....let's upshift to get back to that sound....oooh, wait!!  than it picks up again when the engine hits this type sound!!!   ;D 

Wait hold on......what's that "ba-ba-ba-ba" sound??  Oh, my bad.....the rev limiter....No more sounds to listen for, better upshift again!!  ;)
2001 MS4; Full Termi w/airbox, ECU, SPS cams, CycleCat ClipOn Adapters, Apex clip-ons, CRG's, MW open clutch, Sargent Saddle, CF aplenty.. NOT RIDEABLE FOR A LONG TIME DUE TO MY STUPID LACK OF JUDGEMENT!!

slyfox

Quote from: yuu on June 02, 2008, 07:16:26 PM
But, unless you're a racer and need to worry about keeping in the optimal power range.. you needent worry that much.  Just take it out, .. and just go ride!
agreed

Big Troubled Bear

And remember to keep the rubber side on the tar [thumbsup]
Never attribute to malice that which can be adequately explained by stupidity.

AndrewNS

Ummmm.....if your S2R is stock, it'll never see 9 or 10k RPM  anyway. The rev limiter kicks in at somewhere around 8500. But I agree with everyone else - you don't need a tach to ride these bikes, the shift points are pretty obvious if you just go out and ride.

JoDuc

#7
Quote from: AndrewNS on June 03, 2008, 03:32:13 AM
Ummmm.....if your S2R is stock, it'll never see 9 or 10k RPM  anyway. The rev limiter kicks in at somewhere around 8500. But I agree with everyone else - you don't need a tach to ride these bikes, the shift points are pretty obvious if you just go out and ride.

Full Termi Sysem - The RPM's go up to 11k. There is no 'red zone' which I've had on every other car and bike. I was just concerned about getting them too high. Thanks for all the input, I'm just gonna open it up, see how far she goes and see what happens!!!!!  [evil]

Desmo Demon

My general rule-of-thumb is to rev it until you feel the power taper off and then change gears. It doesn't take much to notice that the power is starting to plateau. It's normally characterized by the bike not seeming to be accelerating as hard anymore. I know my ST2 with the mods that are done to it, it doesn't start tapering off until over the 9k factory redline, but the aftermarket eprom raised the rev limiter to about 10k.

Places I've been on two wheels:

IBA #32735

Kaveh

Butt-dyno FTW here [thumbsup]

Once I got used to the pull of my bike, the sound it makes at different RPMs, I just felt (and somewhat heard) when the power was backing off and shifted. 

No need to look at the Tach while bangin through gears on a straight.  Personally, I use the take when cruising (making sure I'm not lugging the motor or when I want throttle response, trying to keep it in the power band), making sure I am not running to high rpm's when hitting a turn in teh twisties.