81 gs550 highway speed?

[Guest]

And winding it out properly will make a bigger difference.

So at what speeds are you changing gears on your 550? If I'm supposed to already be over 70 mph when I shift out of 4th gear, then maybe I am doing something wrong, but my tach never goes above 7k, no matter how hard I push it.

 

[tkent02]

Are you saying the tach won't work, or that the engine won't wind out properly?

Hope not, a 550 that won't wind out properly is a dog indeed. It's all they've got.

 

[Guest]

i have no idea what 'wind out properly' means. it's not exactly a scientific term. that's what i'm trying to extract from you. at what speeds are you actually shifting? i realize that it's going to vary from bike to bike, but you sound so passionate about this 'winding out' that i'd like to see if i can replicate it, yet you give no details that would help someone know if what they're trying to do is even on the same planet as what you're doing.

 

[GS1150Pilot]

I have been noticing the more I push the needle on the tach the better she runs. There's is just no information out there on how these old gems should be cared for.

There's a buttload of information on how these old gems should be cared for.

 

[tkent02]

i have no idea what 'wind out properly' means. it's not exactly a scientific term. that's what i'm trying to extract from you. at what speeds are you actually shifting? i realize that it's going to vary from bike to bike, but you sound so passionate about this 'winding out' that i'd like to see if i can replicate it, yet you give no details that would help someone know if what they're trying to do is even on the same planet as what you're doing.

What do you want me to say? Don't shift until 11,247 RPM? I'm not going to say that, and if you do that and something blows up don't blame me, but if I'm trying to get my 550 moving in a hurry I shift it somewhere in that vicinity. If it won't go past 7,000 there's something wrong with it, and if there's something wrong with it you shouldn't be whipping it hard until you get that fixed. At least shift it late enough that when it's in the next gear it is still high enough to be making a lot of power. 11,000 is more than it needs to do that, but my point is it hasn't seemed to have hurt anything. Have been doing so on many 550s, since I bought my first one in 1978. Have never had a problem riding them this way. The one I abused the most, when I was young and crazy and all of my friends had bigger motorcycles to keep up with, after 120,000 miles when we took it apart to fix leaky gaskets everywhere, all of the metal parts were still within service limits. Piston rings, cam chain, all of it looked fine. We bought nothing but gaskets, put it back together and whooped the **** out of it for many more thousands of miles. Sold it to my brother, he painted it a unique blue paint job, and years later sold it to some other guy, didn't even tell him the speedo had been around once, and about twenty years later we saw that same bike with that same paint job cruising down the road, still running just fine.

All engines are different, all bikes are different, all riders are different and all roads are different, but the 550s need to wind out a lot farther than any other GS to make the maximum power, due to the odd way Suzuki chose to set up the cam timing.

If you want to lug it around like an old lady in a Cadillac never having any idea of the full potential of this engine that's fine with me.

 

[fasteddie313]

A smaller engine usually has less torque than a larger engine, but the smaller engine also has less rotating mass than a larger engine.. Shorter stroke, lighter pistons etc..

Usually the limiting factor as far as how many RPM you can run is when your valves start to float and grenades your engine, or the head runs out of flow and more RPMs just cannot suck any more air..

By reading this thread it seems you don't have to worry about this engine grenading and can safely rev until the head just can't flow any more air no matter how fast you spin it..

This is how a smaller engine can make up on a bigger engine, by spinning faster, producing less torque but more often vs time, and HP is all about time.

HP = Torque x RPM ? 5252 so 10 ftlbs of torque at 2500 rpm = 4.75 HP, but 10 ftlbs of torque at 12,000 RPM = 22.85 HP

So if your engine can still flow air, the more air your can suck vs time the more fuel you can burn vs time therefore the more HP you can produce because HP is all about time and so is acceleration m/s[SUP]2[/SUP]..

The same reason why ittty bitty formula 1 engines can produce so much HP at 18,000 rpm even with very little torque.

Assuming 100% VE, every time your engine turns over twice, or 720 degrees (4 stroke) you suck 550ccs worth of air at 1 atmosphere of pressure/density.
If you can only do that once per minute or 2 rpm that's only 550cc worth of air per minute you can burn, but if you can do that at 10,000 RPM or 5,000 times per minute (4 stroke) then you are sucking and can burn 2,750,000 CCs of air per minute and produce a lot more power.

Things you can do to increase HP are improve your VE with intake and exhaust mods making it suck more efficiently, adding a turbo for example crams 1100CCs of air into a 550 CC engine at 2 bar of boost, Nitrous just adds more oxygen density to your intake air allowing you to burn more fuel for every volume of suck like a turbo but chemically more oxygen per density instead of just more density of a turbo's pressurized air, and increasing RPM which makes it suck faster therefor more air..

 

[BurntKittyForge]

A smaller engine usually has less torque than a larger engine, but the smaller engine also has less rotating mass than a larger engine.. Shorter stroke, lighter pistons etc..

Usually the limiting factor as far as how many RPM you can run is when your valves start to float and grenades your engine, or the head runs out of flow and more RPMs just cannot suck any more air..

By reading this thread it seems you don't have to worry about this engine grenading and can safely rev until the head just can't flow any more air no matter how fast you spin it..

This is how a smaller engine can make up on a bigger engine, by spinning faster, producing less torque but more often vs time, and HP is all about time.

HP = Torque x RPM ? 5252 so 10 ftlbs of torque at 2500 rpm = 4.75 HP, but 10 ftlbs of torque at 12,000 RPM = 22.85 HP

So if your engine can still flow air, the more air your can suck vs time the more fuel you can burn vs time therefore the more HP you can produce because HP is all about time and so is acceleration m/s[SUP]2[/SUP]..

The same reason why ittty bitty formula 1 engines can produce so much HP at 18,000 rpm even with very little torque.

Assuming 100% VE, every time your engine turns over twice, or 720 degrees (4 stroke) you suck 550ccs worth of air at 1 atmosphere of pressure/density.
If you can only do that once per minute or 2 rpm that's only 550cc worth of air per minute you can burn, but if you can do that at 10,000 RPM or 5,000 times per minute (4 stroke) then you are sucking and can burn 2,750,000 CCs of air per minute and produce a lot more power.

Things you can do to increase HP are improve your VE with intake and exhaust mods making it suck more efficiently, adding a turbo for example crams 1100CCs of air into a 550 CC engine at 2 bar of boost, Nitrous just adds more oxygen density to your intake air allowing you to burn more fuel for every volume of suck like a turbo but chemically more oxygen per density instead of just more density of a turbo's pressurized air, and increasing RPM which makes it suck faster therefor more air..

That's all very interesting. Makes sense. Before I got my GSX1100G, a best buddy was offering to sell me his CBR600...They have the 1/4 mile time up near the top, but I was thinking that's for when one is "burning up" the motor...Not really my style riding.

This is all Making me more anxious to finally "click" with the powerband on mine. (still haven't) , RPM either seems too high to benefit , OR lugging a bit. I tend to go with the lugging. Either way NOT good...been thinking it'll be better once I get the carbs synched, tuned, new o-rings, gaskets and intake boot o-rings soon...
Don't know where the heck to get Mikuni RS o-rings (IF not I'd order from Basscliff link on it)...

IF that + some more riding doesn't click ("powerband") for me I'll just maybe over RPM all the time...get going too fast in traffic and the big 1100 won't really brake on the gears for me though, not even 1st ...

The other issue that used to bug me was my old water cooled bike felt so much cooler that the heat makes me worry still (hopefully excessively)...
I tend to stay about 2000 below redline (on whatever) so I'm finding this interesting , for when have another bike mostly (changing a gasket even would be a PITA for me, especially with just one MC)...

When I was young, before my brother had license , one time he put a 80cc carb on his moped and added a blow dryer w hose running to air intake...funny thing, he added a bicycle speedo calibrated to the 35 or so MPH one and it busted, flew apart at, he claimed 60MPH going down a steep hill...
Those little motors sometimes get a whippet whipped cream N02 from tire inflator, into intake for nitrous...

The really good one he also came up with was LOTS "octane boost" added to gas...I've used up to a whole bottle in tank on a chinese scooter and a tomos, didn't harm either, got around 10MPH more, BUT on idle the clutch will sometimes grab a little (centifugal clutch, higher rpm)...

Been wondering about a "blower" to airbox since running rich anyway...I don't shift fast enough to keep up and my shaft drive gears limit top speed to 140MPH , so no use and unwanted wear...heck the jetted Mikuni carb has me feeling like it's going to bust something (gear-teeth, driveshaft stuff, definately the rear tire anyway, had couple unintentional wheelies even).
Thanks
Just rambling, might get a long ride today, headed out, gotta sort couple things...

EDIT: (Moment later) :been Suspecting my Tach might be off sometimes...going by feel. maybe I'll check it soon (somehow)...(really gotta run, precious warm daylight these days...Urgh!)

 

[tkent02]

A smaller engine usually has less torque than a larger engine, but the smaller engine also has less rotating mass than a larger engine.. Shorter stroke, lighter pistons etc..

Usually the limiting factor as far as how many RPM you can run is when your valves start to float and grenades your engine, or the head runs out of flow and more RPMs just cannot suck any more air..

By reading this thread it seems you don't have to worry about this engine grenading and can safely rev until the head just can't flow any more air no matter how fast you spin it..

This is how a smaller engine can make up on a bigger engine, by spinning faster, producing less torque but more often vs time, and HP is all about time.

HP = Torque x RPM ? 5252 so 10 ftlbs of torque at 2500 rpm = 4.75 HP, but 10 ftlbs of torque at 12,000 RPM = 22.85 HP

So if your engine can still flow air, the more air your can suck vs time the more fuel you can burn vs time therefore the more HP you can produce because HP is all about time and so is acceleration m/s[SUP]2[/SUP]..

The same reason why ittty bitty formula 1 engines can produce so much HP at 18,000 rpm even with very little torque.

Assuming 100% VE, every time your engine turns over twice, or 720 degrees (4 stroke) you suck 550ccs worth of air at 1 atmosphere of pressure/density.
If you can only do that once per minute or 2 rpm that's only 550cc worth of air per minute you can burn, but if you can do that at 10,000 RPM or 5,000 times per minute (4 stroke) then you are sucking and can burn 2,750,000 CCs of air per minute and produce a lot more power.

Things you can do to increase HP are improve your VE with intake and exhaust mods making it suck more efficiently, adding a turbo for example crams 1100CCs of air into a 550 CC engine at 2 bar of boost, Nitrous just adds more oxygen density to your intake air allowing you to burn more fuel for every volume of suck like a turbo but chemically more oxygen per density instead of just more density of a turbo's pressurized air, and increasing RPM which makes it suck faster therefor more air..

I think Suzuki figured out the only way to make the 550 go fast at all was by setting it up to use the highest RPM you speak of, they put the cam timing a lot different than the rest of the GSes to do just that. Changing cams is a lot easier than redesigning everything in the combustion chambers, intakes, exhausts, all of it to flow more air. Pop in a high RPM cam, those who choose to explore the upper RPM get a hot rod, those who never go there don't.

I put 650 cams in my 550 and that entire high RPM kick was gone, you can ride it like a normal motorcycle and still accelerate fairly well. Open the throttle in sixth and it will accelerate, eventually all the way up. Power comes on strong in a mid RPM, continues to build as it winds up, but it doesn't get that big torque surge at 8,000 RPM anymore.
The double top speed thing is gone. A lot easier to ride around in the more normal speeds, a lot less fun to ride as fast as it goes, and it's certainly not as fast overall.

 

[Guest]

HP = Torque x RPM ? 5252 so 10 ftlbs of torque at 2500 rpm = 4.75 HP, but 10 ftlbs of torque at 12,000 RPM = 22.85 HP

yes, wandering off a little here, but all very interesting....

so (theoretically) double the rpm and you double the horsepower,
in real world there are pumping and frictional losses, but it is still the simplest way to increase horse power is to increase rpm.

btw, the "magic" 5252 rpm the point at which the torque and hp curves always cross. Below 5252 torque is always more than hp. Above 5252, hp always more than torque......no exceptions!

to the op , if that bike of yours won't pull over 7k in any of the gears you have a sick engine, you need to sort that out asap.

 

[GSCafe]

I'm a little slow off the line, but I managed 72mph in second today and it was still pulling when I shifted. I'm piped and jetted with pods, so it is very peaky. I might go back to a 15T front, lol. The sound and feel for the bike changes when you enter the powerband. It is still screaming but it feels smooth again.