Top speed with chaindrive.

[mro]

While 10/20 HP make a noticeable difference on a bike, the problem with racing with a drive shaft is leaving it on the ground when you take off or thump in to 2nd. (twisted out a few in my cougar gt back in the mussel car days)

Also can't readily change gearing which would be fun to play with on the XS. Turbo & chain on an XS would be really Xsive!


mro

[pggg]

Hey Hawk, the said individual just enjoys being controversial methinks! Fair enough, good luck to them. One thing with all those weighty steel peices removed from the rear, the bike is straight away noticibly lighter to push. You know how it is with the good ole XS11 when wheeling it around. Take a deep breath, brace yourself, and HEAVE on the handlebars to get her rolling.

[pggg]

MRO, you've gone and done it now. Been thinking nitrous for the last 24 hours. Have decided yeah, why the hell not? Have the forged pistons. Have the fat tyre. Have the good gearing. A bottle gives a couple of minutes boost, and on a street bike you're only gonna use a 3 or 4 second burst occasionally just for the hell of it. Your bike would be 'loaded for bear' always! How does 40-50 extra horsepower at the push of a button sound? Sounds damn fine to me. Project starts as of now!

The local A.P.E. agent down here has bolt-on kits, but, being a cheap bastard, a home made unit appeals better. I have an old fire-extinguisher bottle, and rigging it to a steel braided brake hose shoved into the air box should do the trick. Solenoids, valves and relays rigged between boost button, bottle and throttle would be the trickiest part. Anyone tried it? Should be easy enough. Will report on what happens.

[Pat Kelly]

I think with NOS there is also added fuel with the added oxygen (NOS). Otherwise the combustion chamber becomes overly lean.

[mro]

hey pggg

know the road before you press the button!!!!!

4/5th should go past red line with your set up. One bad bump while your maxed out and who am I going to chat with down under

Also might want to check with other XS drag racers about how the tranny holds up with so much torque.

But been thinking about turbo/chain/nitrous for months now too.

neat thing about nitrous is you can hide it.
Let a bugger get a length ahead, push button and HYPER DRIVE right on by em!!!
Jimmy crotch rockets beware!

mro

[DiverRay]

Hey mro;
check the local craigslist. I found TWO xs1100's, one free, and one $100.!!
I just don't have room, and I do have my winter project already.
Ray

[motoman]

Interesting reading all this, so may as well add my 2cents. With that kinda gearing it should hit the 150. Even being 2-valved and a few minor mods from stock! Have to 'feel' the handleing heading towards those speeds as you know what happens fast. On one ocassion here recently I put my stock 81H factory hardbagger up against my Honda ST11 and stayed with the ST up to 125mph when the ST started pulling away as the XS just hit redline in fourth(maybe a little above redline). Got that speed after the fact from the ST's speedo. Wouldn't wanna push the XS above that, even though still had one more gear, wind changes and such with the large fairing and windshield could spell disaster in a split-second. Even at that the XS was stable(had adjusted spring rate and dampening stiffer and had 20psi in forks). Could tell it didn't have the quite the stability of my ST, as I have hit the 135-138mph on it tucked down behind windshield with elbow on tank resting my chin on palm. The only real advantage I see on a bike like that is frame design, fork rake, and of course the underside spoiler which you can feel just suck that bike down to the road above a 100mph. Power wise, there's not a whole lot of difference, as it makes just a hair over a 100hp. and is 60lbs. heavier. So I'm gonna have to say the XS even being a 2 valve engine still makes power enough to overcome wind resistance and such to hit the 150 mark just with gearing mods to match. Carb intake mods, different cam profiles and such is B.S. It has enough horses and torque stock, and if it can easily redline in 3rd or fourth.....it'll do it in fifth and hit the 150 mark. Above that it may start loosing any gains without some fire built into it. Guess I'm just pregudice, familiar with the ole' XS's capabilities from it conception. Not stepping on any toes, just givin' somethin' to chew on a bit.

[mro]

driverray



Hey mro;
check the local craigslist. I found TWO xs1100's, one free, and one $100.!!
I just don't have room, and I do have my winter project already.
Ray


On my way to craigslist


thanks


mro

[mro]

Thanks DriverRay

got his number and will call tomorrow
(2 listings were same guy/same bike)



mro

[pggg]

Hey Moto, 135mph is light years away from 150mph. Believe me mate, for each single mph increase, you need BIG BIG horsepower increases to smash thru that wind wall on an XS11 - no matter what the gearing is. If a bike redlines in 5th with stock gearing, it certainly don't mean it'll do the same with a taller gear ratio. Repeat - that wind wall is SOLID! There's a HUGE difference between 125mph and 140mph. Above 130 it get's hard to breathe. Each tiny gain is a huge mission. When we're talking XS11's and the like, we're talking the most unaerodynamic vehicles you can get! By nature a motorcycle with rider is extremely wind catching. Your common family car is way more wind efficient. On paper, figures may say this and say that, but the ACTUAL top speed run is a completely different story.

[motoman]

That's interesting pggg as I figured since your most likely close to sea level compared to my 5,000ft. elev. that being a definite advantage relative to h.p. output. Thought since my ST will make the 135-138mph in stock form at my 5,000ft. elev., and get there in less than a mile run, figured surely your XS with the mods. and advantagious low elev. would hit the 150 mark, plus being kinda down-under going down hill(sorry, couldn't resist that, that's what I'm all about, havin fun here). Anyway, be careful, cause above 50mph s*#t happens quickly! Can attest to that as well as others here over the years could attest to also.

[xs650mike]

Wind drag factor

pggg's absolutely right about this, wind drag increases exponentially with speed. It takes really big HP to get to 150 mph, even with a faired bike. Also don't think just because your speedo reads 135 that you're going that fast. IIRC magazine road tests of early XS11s had top speeds around 128-130 mph. Just to illustrate the power difference as speed increases it only takes about 16 or 17 HP to reach 70 mph. That doesn't mean that 34 HP will get you 140, you'll be lucky to get 100 mph lying down on the tank with your feet straight out the back like Rollie Free.

[motoman]

Thanks for all that Mike. Myself and my 81H like it at 70mph. Thats where it's 'comfort' rpm zone seems to be, although fuel consumption would be a little less than the 36mpg at a slower 60mph cruise speed. My 92 ST likes anything up to 85mph, after which the 50mpg starts dropping with 2-up on it. Have to watch it on it as being so quiet and not 'feeling' sensation of speed it'll creep into the triple diget with 2-up without realizing it. The throttle lock helps, and gives my wrist a break on those long interstate runs too. Also wanna wish you and everyone here a SAFE and happy Holidays. And if your still riding as I am, ride and drive for all the unconscious ones, specially those with cell phones stuck to there ear while driving.(won't go there, as you can guess)

[pggg]

Moto, John says motorbikes down here run backwards. Maybe he meant the owner Air's thicker at sea level so more wind resistance? Negating the oxygen advantage? Nitrous at 5000 ft could be fun

[GNEPIG]

.. hello pggg, any up dates on your pending nitrous adventure?