You'd have to fit it with a colostomy bag to pass the emission test at certification
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You'd have to fit it with a colostomy bag to pass the emission test at certification
Originally Posted by FlangMaster
L-Plate Rider
This is me first post on here; I've enjoyed this forum from afar for too long.
Steve Rothwell here, I am the other half of TSS-The Two-Stroke Shop. I'm the ugly one, and your very own Wayne 'Wobbly' Wright (Yes, he of the BSL500 fame) is the clever and good-looking one.
I don't want to come across as being preachy or self-serving - it's just that there is much talk on here about two-strokes being peaky and having no torque. A lot of ill-informed four-stroke biased claptrap.
I fail to see why there seems to be such a hold on the collective consciousness of motorcyclists today, especially stroker fans on this forum, to hold sway with the four-stroke status quo.
Just what exactly is to be achieved by giving the same old, same old the nod - just because it's there, and conventional wisdom upholds the four-stroke motor as the vanguard. But why? Because the engine is there, and lots of them are sold, because there are no other choices available? Where's the fun in that?
Yes two-strokes can be peaky, especially the old-school non-reed-valve motors, and also because they are very small motors. But you know you're alive when riding them! Unlike riding a current-model ZX-10R for instance, with its flat boring torque curve and stepless acceleration. If I wanted linear power, I would get myself an electric milk float!
But regardless of engine sizes, the 2T ALWAYS pumps out more torque, all the way from idle, than a four-stroke of the same cc. In fact here's a fine practical example.
Check it out: Here we have a screen shot of two comparo dyno runs of the slowest of all the RZ350 YPVS variants, the Brazilian-made RD350R with its measly 5:1 compression ratio, against a Suzuki Bandit 400 - a more modern engine platform than the venerable RD, and with a 50cc capacity advantage.
Notice these things:
1) The boring as batshit four-stroke power/torque curve
2) The dead exciting mountainous torque curve of the RD350R
3) The RD's marked increase in torque - even at the bottom end.
There is nowhere on the rev scale where the four-stroke defeats the two-stroke on torque output - unless of course if you want to be unfair and follow the Bandit's wheezing journey to ridiculously high revs, and compare that with the RD which has signed off several thousand revs before. But that same RD has already grabbed another gear, and has overtaken the Bandit.
And the Bandit will never be able to attain the same performance/top speed/acceleration as the RD, even though it has a virtually identical peak horsepower figure. It's all about the torque. Check it out:
http://www.twostrokeshop.com/curveRDR4CE6.jpg
The RD350R would only 'feel' flat down low because there is so much more oomph higher up; so you ignore what urge is down low in favour of zing up high. But the real message is that the RD350R, even when below the powerband, will still out-grunt the Bandit 400, and the RD's engine and total bike weight is considerably less than the Bandit's.
And our 1100cc two-stroke triple will produce just shy of double the torque of the ZX-10R motor. See, the thing is, there has never been any serious attempt to face off a modern two-stroke of equal capacity to today's four-stroke litrebikes, and so a lot of people are going around with memories of 250cc ring-a-dings that were minted 25 years ago.
We will all find, and happily so, that with the benefit of like-for-like cubic capacity and modern engineering technologies, that the two-stroke litrebike will trounce its four-stroke counterpart.
And again; since the engine will run modern power-valve technology designed by New Zealand's own Wayne 'Wobbly' Wright (Wayne designed the BSL500 engine, about which there is a thread on this site), it will be tractable and devastatingly torquey even from very low revs.
In short, it will piss all over four-stroke 1000s, Hayabusas, come what may.
And I repeat: not even at 1500rpm will the ZX-10R engine live with the TSS1100GP for horsepower or torque. Sure, the 4T will rev higher in order to make its lesser offering of power and torque; but then again it will have to rev high because it's dragging valve gear around, and dragging pistons over two idle strokes every firing event.
The reason two-strokes have got a reputation for not being able to pull the skin off a rice pudding below the power-band is simple: said two-strokes were tiny in capacity, old metal from at least 25 years ago. And of course, they have animated power/torque curves, which means mucho excitement.
I do hope I have not offended the thin-skinned and I apologise in advance to the many people who read this and think I am trying to tell them how to suck eggs. I just feel the two-stroke deserves a right of reply. Obviously Wayne and I are immensely passionate about the two-stroke engine and we feel it has a lot to offer. If it's given a fighting chance. And hopefully we will in future years be able to bring to market a new generation of 'clean' direct-injected two-strokes - and let's be dead honest here ... the motorcycle is predominantly a single-person vehicle, whose dynamic performance improves in all respects when it is made lighter and with more power and torque.
Therefore, you will see from TSS new bikes like the WR500SM - a Yamaha WR450 Supermoto freed of its four-stroke single, and fitted with our 112hp TSS500GP motor.
Yes, we believe the world deserves bikes that are Light AND Fast.
Best regards,
Stephen Rothwell
The Two-Stroke Shop
www.twostrokeshop.com
9 Compass Close, Edge Hill
Cairns, Queensland 4870
Australia
Tel. (In Australia): 0427 774 285
Tel. (Outside Australia): +61 427 774 285
Forum whore
Fantastic post mate! It's always a priviledge to hear from the one's who are actually DOING the work and research!
Hey, even if you come across as slightly biased towards 2-strokes, I can't see anyone here complaining about that, either.
If the RS250 wasn't so high maintenance, I'd love one in addition to my cruiser - heck, I'd love one anyway if I could convince the Missus a top-end rebuild every 18,000km was good value... and that a 250 that was as fast as my 600 and a race-bike for the road was a good thing for a Grandpa to have...
As for older bikes, there are many fans here of the 2-strokes from the '70's. I loved my old T500 and dearly wanted an RD350 and that short-lived Kwaka 400 which took over from their 350, (it handled!).
Power? Well I found my '89 GSX600F to have plenty for the road and felt the latest Bandit 1250S to have far too much torque! But of course, by the time I gave it back I was getting almost as hooked on it as the M109R.
I do hope you and Wayne can achieve your goals, if the bike performs in the real world, you should be viable at least - very successful at best.
Keep us up to date, eh?
You don't get to be an old dog without learning a few tricks.
Shorai Powersports batteries are very trick!
Last of a dying breed
If there was a decent big CC 2-stroke I would have it tomorrow (as long as I could afford the baby).
Not even close to the same as your stuff, but I have grabbed a few old Suzuki 100 - 185cc dirt bikes, resurrected them, and had some serious fun with them. I also have had/still have old 250 and 500 cc dirt bikes, and the small 2-strokers always are lighter, faster and throw up more dirt.
And the 2-strokers are so much simpler to work on! (Then again we are talking about air cooled 10 - 20 year old bikes here)
But what does interest me is what is the fuel usage for your motors?
And thanks for your input. Don't be a stranger!
Forum whore
My '70 Holden Premier with its 308V8, (5 litre), put out 240hp and I could get 24mpg with light throttle. Kinda puts 250hp into perspective a bit when you can exceed that figure in a vehicle weighing less than the V8 engine!
250hp drinks fuel, ask any 'Busa owner with only 190hp. I would be interested in the comparison, though. Direct-Fuel-injection should make a difference.
You don't get to be an old dog without learning a few tricks.
Shorai Powersports batteries are very trick!
Long Haired Yobbo
Awesome to see you guys making bikes that are REALLY COOL!
Heinz Varieties
Valiant Man
I Suppose somebody has to make the Kawasaki's go faster cos Kawasaki can'tI like the two strokes nice sound nice smell.
Lorenzo World Champ
HellSpawn
Now we need a Two Stroke Performance Tuning thread
for all us fanatics
the art of diplomacy is saying nice doggie,
until you find a big rock
Forum whore
Preach preach! Steve and Wayne have definitely got the magic stick!
Here to make everything METAL
Aaaaaaaaaaaaaaawesome.
Terrifying, no doubt, and rather expensive to maintain, but awesome nonetheless.
What you have in your heart will be revealed through what you have in your life.
If things are going badly in our circumstances, the answer to what is happening to us outwardly is more often than not found in the mirror.
Hardcore Biker
Ooo Cairns....I'll be there in July, if I bring a carton of ice cold VB, can I have a look....
Forum whore
Just watch the mozzies right now, Dengy, (sp?) fever is a problem there at the mo.Ooo Cairns....I'll be there in July, if I bring a carton of ice cold VB, can I have a look....
You don't get to be an old dog without learning a few tricks.
Shorai Powersports batteries are very trick!
Forum whore
I agree with what you have written, and sure, it is totally feasable to have such an engine, but I can't help but wonder what sort of effort is going to be required (as far as traction control etc) to make such a machine rideable.
The MotoGP teams have spent so much time and effort in achieving just that (OK, granted 4T engines have issues that are not such a problem for set up like a 2T, ), but what sort of systems do you have planned to put all that power to the ground?
I am not knocking the idea, I just have a genuine interest in this aspect!
Homo Sapiens Vulgaris
Now that sounds like fun! ...if somewhat lethal. A somersault on wheels pretty much.
It is preferential to refrain from the utilisation of grandiose verbiage in the circumstance that your intellectualisation can be expressed using comparatively simplistic lexicological entities. (...such as the word fuck.)
Remember your humanity, and forget the rest. - Joseph Rotblat
The instructions are simple...
Quite possibly.
Torque = acceleration...HP = top speed. Right?
My only experience with 2 strokes is a TS125 and a T500. Narrow (relatively) powerband and absolutely no zing outside of it. And I do tend to associate torque with engine-braking.
Apologies to those I've upset
Do you realise how many holes there could be if people would just take the time to take the dirt out of them?
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