New project: XS1100 endurance racer

[81xsproject]

The first exhaust we put on my buddies '77 KZ1000 was some one-off, 4-2-1 that we found on eBay. It combined #4-#1 and #3-#2 at the 4 to 2 y's. My buddy didn't like the looks of a black header with chrome muffler, so he dropped the change for a V&H 4-1. There was a noticeable drop in performance. I would LOVE to build a setup like that for my 11.

[Mathh]

Would you consider fabricating a 4-2-1 design? That would very much simplify your plight (as the right pair of pipes are aligned and touching, and the left pair of pipes are aligned and touching) if you cut another inch and a half or so from the ends (eliminate the outward bends) It appears that it should line up better, and then you could use some 2-1 Y-pipes, starting with inlets that are equal to your pipe's diameter, and an outlet slightly larger, then use a small length of pipe to connect the two sides together, with a slightly larger yet Y-pipe. I had thought of building a design like that for my XJ650, until I realized it would be too long. (My outlet going to my muffler would be farther back than the rear footpeg) But perhaps it would work for your application. Speaking of which, what are you planning on using for a muffler? Or do you plan on using any muffler at all?
See this stock CBR1000RR pipe here That is what I got, and cut up to make my pipes that I abandoned. (still have all the pieces though...)

Yeah, I'm considering that as i have a stainless 2009 Blade exhaust at home and some more primary and secondary extractors. Problem is exhaust fabrication is a science in itself. That same science says that with a good 4 -2-1 cylinders #4 and #1 and #2 and #3 should be combined for bikes with a 180 degree design (as our yam). In my case I am combining #1 and #2 and #3 and #4. However the Blade exhaust proves this science different.? This is a nice read : click.
I have to do some more research befor i make a decision. Great thinking Daveyg!

[daveyg]

Would you consider fabricating a 4-2-1 design? That would very much simplify your plight (as the right pair of pipes are aligned and touching, and the left pair of pipes are aligned and touching) if you cut another inch and a half or so from the ends (eliminate the outward bends) It appears that it should line up better, and then you could use some 2-1 Y-pipes, starting with inlets that are equal to your pipe's diameter, and an outlet slightly larger, then use a small length of pipe to connect the two sides together, with a slightly larger yet Y-pipe. I had thought of building a design like that for my XJ650, until I realized it would be too long. (My outlet going to my muffler would be farther back than the rear footpeg) But perhaps it would work for your application. Speaking of which, what are you planning on using for a muffler? Or do you plan on using any muffler at all?
See this stock CBR1000RR pipe here That is what I got, and cut up to make my pipes that I abandoned. (still have all the pieces though...)

[Mathh]

And another update:
I have some more grey hair now after last week... I shortened all downpipes 1.5 inch so the radius starts immediately after the flange. Because of that I had to widen the
exhaustrings and mounting holes. This Supertrapp collector was a piece of art and extremely accurately built, now a bit less accurate ... jeezz..



I tilted all four downpipes inwards, the outer ones a bit more than the inner ones..





It was a pain in the neck to get the pipes a bit symmetrical viewing from the front, have them run around and over the oil filter cover (must be removable with the exhaust on) ánd let them come together at the bottom (top in the pics).
That coming together did not work that well with pipe #1, that one needs another bend in order to use the old collector again...



Both my welding bottles are empty now, going to do that first now...

[Mathh]

I have been busy adapting the downpipes. That is a pain in the neck because there is no room to play with and the stainless is only 0.8mm thick. Will be very hard to weld and keep it clean....
Okay first thing is to hack up the Supertrapp collector,before:



after:



Shortened the downpipes on the cylinder side:



Exhaust side now with separate flanges:



test fitting, frame and engine upside down, oilfilter cover must be removable, even with the collector in place:



made the outer downpipe radius as tight as possible, but they still touch the framerails... :

So I am now thinking of modifying the frame after all or figure out if i can turn the outer 2 downpipes inwards without losing height (only one finger room between engine and collector box left) and without having to rebend the downpipes (that will be near impossible I guess).

Thanks to the owner of Sparks Trading here in holland I am now the happy owner of a Dymag magnesium cushdrive, 41 alu sprocket in 520....and yesterday I received my matching front wheel from France (brand new and boxed since 2003):



No weight problem there, less than 3 kilos:

[kta]

This build is AWESOME!

more more more!!!!

[Mathh]

Just called the shop. On a car, the engine will turn 6K RPM, and the Alternator is geared for 2 or 3 times engine speed. That says 12K or 18K RPM with no problem! Should work!

Wow! that is good news. Thanks a lot!

[DiverRay]

Just called the shop. On a car, the engine will turn 6K RPM, and the Alternator is geared for 2 or 3 times engine speed. That says 12K or 18K RPM with no problem! Should work!

[Mathh]

I'll check with my local shop Monday. The part number is a STANDARD one, and I know they can look up the specs for the alternator. You may still be able to use it, just let me know how fast you want to spin the alt.

Thanks! It would be nice if it could reach approx 9-10000 rpm (Yam max crank speed). That way I can calculate optimal pully sizes in order to get an early charge (as early as possible) without overrevving it. I know there are race alternators that already charge at idle but usually they start at higher Amps (100+ Amps). Would be nice if you could look into that as well. I picked this alt because of its size.

[DiverRay]

I'll check with my local shop Monday. The part number is a STANDARD one, and I know they can look up the specs for the alternator. You may still be able to use it, just let me know how fast you want to spin the alt.

[Mathh]

Tod,
Look at the picture with the cap off. Do you see at the back of the breather there is a drain from one side to the other? That will take care of the liquid, and a quick bit of work with a dremmel will take some material off the bar between the two chambers for the vapor.
If Mathh drills the holes a little deeper, he could put in 5mm longer screws. That will hold a LOT of weight. Don't forget, he has a tab on the other side of the engine for that mount, as well as the front and bottom mounts.
Great built!

I was thinking about pulling the right side crank cover, and putting a pully on the crank instead of the alt that Yamaha used. If you did something like that, you would charge all the time.

That is correct of course PLUS I can bumpstart or use the kickstart when the battery is empty if I use a normal alternator with pully drive. That is not possible with a piggy back alternator because they are designed differently. But I already used a crankdrive system on the turbocharged bike. I want this bike completely different. Also i want to shorten the crank for more ground clearance, and maybe convert the stump for use with a portable starting system. That may however come later, top priority is getting the bike running around june - july for our next international meeting in Germany...
Another plus with the separate alternator is the built in regulator and rectifier. That simplifies wiring a bit.

@Trbig: I was referring to the lateral movement and using tensil strength. As Diverray says, there are six solid engine mounts in total.

I just received an email from the seller of this unit click
that he has no clue on max allowed revs... that's a shame..

[DiverRay]

Tod,
Look at the picture with the cap off. Do you see at the back of the breather there is a drain from one side to the other? That will take care of the liquid, and a quick bit of work with a dremmel will take some material off the bar between the two chambers for the vapor.
If Mathh drills the holes a little deeper, he could put in 5mm longer screws. That will hold a LOT of weight. Don't forget, he has a tab on the other side of the engine for that mount, as well as the front and bottom mounts.
Great built! I was thinking about pulling the right side crank cover, and putting a pully on the crank instead of the alt that Yamaha used. If you did something like that, you would charge all the time.

[trbig]

So you'll only be generating when the back wheel is spinning?

Also.. the original cap over this vent is cup shaped. It allowed gasses from the crankcase on one side and the middle drive vent to have one hose. By capping that flat like you have, you'll block off the crancase/ blowby pressure, and you'll need to either drill out a hole in the divider there under that cap, or make two different vent holes.

And one other thing.. those screws on a rotor are stopping lateral movement and using their tensil strength. That application is going to test the aluminum threads in an up and down pressure. Just another of my 2 cents.. lol.

Tod

[Mathh]

yes, with the welding I referred to the aluminum plate..

You're asking a lot from those 4 little allen screws. Under that cover is one of the 10mm bolts that connect the two case halves. One more hole in the center of that and a longer bolt would give you a little more strength there?? You could also drill it and tap it for a larger bolt to give it even more strength.
Tod

I am not afraid of those 4 little screws. Honda for instance bolts their stock Fireblade rotors with 6 of those tiny M6 screws. The forces on those poor discs while braking are way bigger.
But your remark about the bigger 10mm is excellent, great, I did not see that possibility!

The alternator/ generator will be driven from the front sprocket just like in these pics:





Still thinking about pulley sizes and which alternator to use though. The bike in the pics has a 1:1 pully drive and starts charging at a speed of around 30 mph. That's great for a track bike, but I want to run mine on the street as well. Maybe one from a race car like this one, but I am waiting for a reply on max revs...

[Mashermoto]

I'm still recovering from hacking up a perfectly good stainless steel SuperTrapp header...but I digress