custom fab'd pipes and performance

[Tech7]

I meant everyone elses 650's. MY bike is wicked fast! Hey Scott, I'm thinking 1-1/2" for my GS450 as well. Whadya think?

 

[oldbiker]

hi guys on my 1976 xs650 yam . i,m running mikesxs 38 kits with etra jets in carbs along with 45mm stainless pipes and tracker mufflers,, twins on each side ,, its nice and clear ,,, although it does bark above 4000 nice and crisp,, i don,t do that in town .. i,ve never had trouble,, regards oldbiker

 

[jay760]

Thanks GS at last someone has put some figures down, is that 1 1/2" inner or outside diameter. I used to measure and cut my Triumph pipes all the time, from memory I think they were 1 3/4 and 36" long might be wrong with the length though

 

[gggGary]

Cyclone M2,
Talk about trying to get horsepower out of a turnip????

I shouldn't even comment cause my "need for speed" is almost gone.
Had a lot of fun last year on an FZ1 but no matter how fast, great handling. excellent braking, etc. it is, a toaster is just another appliance. Yawn.

What about the benefits??? of 2 into 1 or a cross connect pipe like the old headers had? Should improve scavenging? Do you think that is where your 3HP is coming from GS?

 

[gordonscott]

Cyclone M2,
Talk about trying to get horsepower out of a turnip????

I shouldn't even comment cause my "need for speed" is almost gone.
Had a lot of fun last year on an FZ1 but no matter how fast, great handling. excellent braking, etc. it is, a toaster is just another appliance. Yawn.

What about the benefits??? of 2 into 1 or a cross connect pipe like the old headers had? Should improve scavenging? Do you think that is where your 3HP is coming from GS?

M2 1200 Cyclone: 103hp 85ft lbs of torque, weight 436lbs. XS650: 42hp 42.8 ft lbs of torque weight 426lbs. I would hardly call the Cyclone a turnip Is it stupid fast, no! But it does great for what it was made to do. I have it because it is not like an appliance, it has soul and personality, it's like driving a "70" LS6 Chevelle that handles, total rumble I know what you mean about "appliance" my v-strom is just that the M2 is anything but! By the way Gary it's not taken personaly, you just don't know what you're talking about Ok the pipes, on all the old dyno tests they did not see any added HP with a crosspipe? I know, I thought they would have too? But they say don't bother My 2into1 was a total surprize to me and Roy Fisk ( torque at low rpm), he predicted my glasspack hi-pipes would do better and I aggreed, we were both wrong, go figure? I made some replica pipes of the ones they were testing back in the 70's (exact spec) and the resulting dyno testing was the same as theres.

 

[gordonscott]

Thanks GS at last someone has put some figures down, is that 1 1/2" inner or outside diameter. I used to measure and cut my Triumph pipes all the time, from memory I think they were 1 3/4 and 36" long might be wrong with the length though

Hi Jay, thats 1.5od 16ga tube.

 

[gordonscott]

I meant everyone elses 650's. MY bike is wicked fast! Hey Scott, I'm thinking 1-1/2" for my GS450 as well. Whadya think?

I would'nt have the faintest idea? I would see what size the aftermarket header companies where using back then and start there. P.S. I have the slowest xs650 in captivity, but it will climb tree's

 

[drgonzo]

While written by and for CB350 racers/tuners there is good exhaust info here:
http://www.eurospares.com/pipes.htm

 

[XSLeo]

His length formula doesn't work. 204,000/.85 X redline. 204,000/.85=240,000. 240,000 X 7500 = 1,800,000,000 That's a long header.
Maybe thats divided by rpm not x. That would be 240,000/7500 = 32. 32 inches sounds better.
Leo

 

[drgonzo]

that would be:
204,000/(.85)8000)
204000/6800=30 inches from valve face to exit.
I say it stands.

 

[XSive Force]

Hello to all.

Finally found the bike and decided that it was time to join the group.

I intend to build a Bobber of sorts. The goal is to have something to carve the roads through canyons on the way to the lake.

This leads to the first of what I'm sure will be many questions. I've looked at the Lo Brow hardtail kits and I'm wondering what stretch and height I should be considering. I'm a big guy so I think some length is called for. I don't want to sacrafise handling but readily admit that I am no knee dragged and would probably never find the bike's limit.

Is there a rule of thumb? A common path?

Any help is appreciated and I look forward to your remarks.

My name is John

PS I see I've already screwed the pooch!

 

[grizld1]

You want a canyon-carver, and you're going to hardtail the thing?! You're probably not gonna hear it, so you'll have to feel it. Try this before you take a Sawzall to your frame. Cut a pair of solid struts from heavy bar stock, throw that scoot into a corner, and see what happens. Just be sure you have plenty of runoff room and wear all the gear you own.

 

[XSive Force]

Hello Griz.

Thank you for you candid response. Perhaps a re-evaluation is appropriate. Had a friend that had a rigid Harley that seemed quite capable and able to keep up on the turns. (Please note my comment about not having the desire to drag knees.)

If my choice comes to a bar hopper instead, is there a best stretch and drop that at least considers handling?

Also, now that you have me at least considering keeping a suspension, are you aware of a modern aluminum swingarm swap?

Thank you again for your quick and respected response.

John

 

[grizld1]

John, the issue with hardtail conversions isn't just the stretch and the drop; it's the fact that the shocks keep the tires hooked up to the pavement. Some guys are going to tell you that a big, fat tire run at low pressure will fix that. That's BS. Nothing besides a pair of premium shocks is going to deliver decent damping, which is what keeps the rubber on the road, and a big fat tire will make the machine handle like a truck. As far as drop is concerned, the XS650 is already challenged when it comes to clearance. I flat don't see the point of a bike that "looks badass" and makes the rider corner like Granny in her minivan--all the vulnerability of a motorcycle, with the agility of a Supermarket Special.

You have to thrash one of these machines pretty hard before actual swingarm flex becomes an issue. There's quite a bit written on switching to modern box-section swingarms. Most are steel. Aluminum has to be pretty thick for use in a swingarm, and the few I've weighed out against the stock unit didn't justify the mod. You can eliminate much unsprung weight with duraluminum spacers in the wheels (mine came out of a KTM dirt bike and were cut down to size), plastic chain guard, 520 chain and sprockets, and so on. 5twins uses a TX750 swingarm for more rigidity; weighs around 2 lbs. more than the original. Dwayne Burge notes that once you've made the swingarm more rigid, frame flex at the swingarm pivots can become an issue; he recommends welding a piece of bar stock across the pressed steel elements that house the pivot points to eliminate the chronic problem of the threaded end of the swingarm pivot bolt snapping off.

Hope this helps. My advice still stands--get your bike going, ride it a bit, then cut yourself some struts and bolt them on and see if you can live with that. Then make an informed choice, before you've done anything irreversible. Bottom line? You either want sharp steering and flickability or you want the look that's been marketed on TV by OCC, Jesse James, and the rest. I didn't think much of chewing up a bike for the sake of image back in the 60's, and I don't think any more of it now.

Before you guys jump on me for being a "purist," I can tell you right now that I've carried out more mods where you can't see 'em than you have with your Sawzalls and welders.

 

[Jack]

You "Purist Protesters Suck" Oh!Hey Griz

 

[retiredgentleman]

Now you've done it grizld1!

The "hardtail" gang will be using social media to round up a posse. They'll be coming for you................probably tar and feather you

 

[grizld1]

They'll have to catch me first, RG, and this ain't the flatland part of Illinois. Hey Jack, are you going to make it to Townsend this year? You need to see what that head work of yours does with a pair of Mikuni 4-stroke pumpers hanging off the intakes.

 

[hotrdd]

I have homemade exhaust and intake and so far on the Dyno they seem fine. Though it hasn't seen any road work yet.

Right Pipe = 29" Standard pipe + 13" of 2" ID
Left Pipe = 36" Standard pipe + 13" of 2" ID

Intake is K&N cone filter single split to feed both carbs.

Max Power 41.40HP & 39.22 Torque

 

[englishrose]

So is it a necessity to run inner tubing in the exhaust pipes?

 

[jamesgs4]

no, just tune your carbs to your pipes, not the other way around.