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Re: 30 bhp whats it feel like
Posted: Fri Mar 20, 2009 10:39 pm
by Juan
I'd not say GPS is totally accurate. A mate of mine got a reading of 90 mph on his boned down Malossi 166 running on 200 gearing, by my reckoning he'd have to have pulled around 11.5 - 12,000 rpm for that to be true. I think he must've been pointing it at the BMW 5 series in the fast lane.

Re: 30 bhp whats it feel like
Posted: Fri Mar 20, 2009 10:48 pm
by teamv
Ive had my rb250 over 80, but i dont think it would do it on a fixed mile ,well not with me on it as i am to heavy ,but it may do with someone lighter ,

Re: 30 bhp whats it feel like
Posted: Sat Mar 21, 2009 10:44 am
by Special X
Looking at the graphs in the small block shootout there's more area under the curve in the Imola than the RB20. It looks as though the RB will seem more impressive due to a peaky powerband but . . . with the right gearing . . . I believe that the Imola that was tested will beat the RB20 tested on top speed and will cruise more reliably due to lower revs. I've followed 2 Imola's on my X9 with a GPS corrected digital readout, and both managed very close to 80 mph (79+) on the flat for long stretches.
One was Corrado's orange GP and the other Davy's S2. Davy had only 1 front hub nut on when we stopped . . Scary!!!!
Re: 30 bhp whats it feel like
Posted: Sat Mar 21, 2009 9:36 pm
by jonny snatchsniffer
ok then so what power delivery do you all like then ? i think id like the leary kick up the arse type
Re: 30 bhp whats it feel like
Posted: Sat Mar 21, 2009 9:54 pm
by cezeta
jonny snatchsniffer wrote:ok then so what power delivery do you all like then ? i think id like the leary kick up the arse type
4 stroke enduro bike style power any day, power everywhere.
cant see the need for a power band, i have always seen it as a flaw rather than a benafit hence the developments in power valves and injection to fill the gap in the power.
just my view though
Re: 30 bhp whats it feel like
Posted: Sun Mar 22, 2009 12:28 am
by tony
Injection? Do you mean the Bimota V Due with the 1500rpm powerband? Or do you mean the piaggio 50cc injected motors?
The power band isnt there for 'the need of a powerband' . Its a product of getting the motor to work in sync. The exhaust powervalve widens the band by lowering or raising the ex timing as you probably know. But its there to improve the torque and keep the motor pumping efficiently. This powerband is a trait of the two stroke engine. I think you really want a 4 stroke engine. I'm sure Frank does a conversion along these lines.
Re: 30 bhp whats it feel like
Posted: Sun Mar 22, 2009 10:45 am
by jonny snatchsniffer
mmm 4 stroke, i think the grin factor of the two stroke (pound for pound) is much more fun, take for example gsxr1100 or rg500 i know what id rather have, the powerband is fun its what makes me grin
Re: 30 bhp whats it feel like
Posted: Sun Mar 22, 2009 11:46 am
by cezeta
tony wrote:Injection? Do you mean the Bimota V Due with the 1500rpm powerband? Or do you mean the piaggio 50cc injected motors?
The power band isnt there for 'the need of a powerband' . Its a product of getting the motor to work in sync. The exhaust powervalve widens the band by lowering or raising the ex timing as you probably know. But its there to improve the torque and keep the motor pumping efficiently. This powerband is a trait of the two stroke engine. I think you really want a 4 stroke engine. I'm sure Frank does a conversion along these lines.
I think the aprilia bimota and piaggio are using the same australian injection system? scooters aside its a really interesting time for the two stroke as honda have an injected enduro bike now lotus are developing one and the bloody twist and goes are super fast now as a result.
there are so many two stroke technologies out there that dont end up on an old scooter. look up a wordill for example it uses a piston inside a piston to counter the dead spot before the power band.
i used to race enduro (edit: let that read dabble....no winneybago and support team.....transit from work and a can of tyre weld more like)when i had hair and so remember the power valve and lc introduction. massive change in engine and power delivery. the 4 strokes took over though as they were just so much faster in practice. i had kdx s but would be on a drz or wr400 now given a choice.
the power band is a design option, its not mandatory just look at an enduro bike v a mx bike. same bike with differant uses and differsant power delivery. the enduro bike has less of a power band as its not desired.
but yes, a husaberg lammy would be nice
talking to john at jb on friday he asked me to come down and ride his ts1 as he believes he has got that 4 stroke grunt and power delivery i am looking for, we ll see.
Re: 30 bhp whats it feel like
Posted: Mon Mar 23, 2009 12:10 am
by tony
The enduro two stroke bike has a power band nick. Its just tuned to deliver it low down. I think want you want is a low revving motor that delivers its torque without the hi revs we all seem to love. Thats possible. A reed motor will help. But its all done with the correct timings pipe and areas. Maybe speak to Ralph95 on here. Ralph has been tuning torque monster lambretta motors for years as he is the sidecar champion. They design their motors with low transfer timing but big areas I would imagine. He would be able to help I'm sure.
Re: 30 bhp whats it feel like
Posted: Mon Mar 23, 2009 8:42 pm
by cezeta
cheers tony, i wasnt denying the existence of the power band just the need for such an on off one for some uses or personal tastes. my tastes have changed, my ts1 used to run a kegra race pipe like on the drag racing vid that someone put up. like on the vid the first gear needed the clutch to get it to pull away then WOW

it would spin the rear in the wet on bends which i was never quite sure if i liked or not but i would still try to do it
I then rode vfr 750s (v4) and triumph 955 daytonas (tripples) and just loved the very easy power of super grunt, cant beet it. there is still a "power band" on the 4 strokes as they rev but that slow revving grunt makes a fast bike which is why the race version of the vfr dominated the superbikes for so long untill other grunt monster like the 916 came along. All else there after was a bit lacking

(to be fair my scooter has 100 bhp less than my road bikes so no suprise there)
Im not discrediting those that like the kick of a tuned 2 stroke but the question was "ok then so what power delivery do you all like then ? " and so the best way to describe my preference of tune is like a four stroke.
I also accept that on a small capacity machine then tuning rather than ccs gets the results but take a standard et3, there is no detectable power band but given 3x the cc s it would go like the clappers. If you look at the p2 exhaust test, i would describe the standard p2 as four stroke style power and any power band is negligible.
http://vintagescooters.free.fr/tuning/p ... xhaust.htm
I did speak to frank about doing a series 1 (my favourite) with a vfr400 v4 engine. he said he could do it but work over the past 6 months has been a bit iffy and my pool of dosh has dwindled so im struggling to justify it.
just to make a comparison here is a dynoed kdx200
http://justkdx.dirtrider.net/dynotesting.html
and a klx300 which is the 4 stroke version
http://www.motorcycle.com/shoot-outs/qu ... 87985.html
forgeting the numbers for a moment, the shapes are very similar. the kdx is a very easy bike to ride. ironicaly the wr which is a 4 stroke has a power band, the 400 is quite a kneck wrencher in fact......i prefer the 250....i have soft hands
