Scored a 4-1 for my 79sf...

[Shuriken]

The current pipes on my 79sf are nothing but headers to which someone has fitted some kind of kawasaki road bike mufflers to. They are leaky and not even welded, and the baffles sound nonexistent. Of course the crossover pipe is gone, too.

I wonder what I can expect out of what will be the new 4-1 setup. I haven't ever used a 4-1 on the yammy. Didn't get this set of pipes with performance in mind - just saw a good price. Seems exhausts are hard to find - intact.

So I guess we'll see.

Ben

[MartyA]

Original 2-1 are tough to find. "Performance" exhausts are still available, in chrome and black. Last I looked, Motorcycle Accessory Warehouse was selling black 4-1 for about $350 ish, I forget if that was with a megaphone exhaust or not. Chrome was $450 ish.

Standard fare for the 4-1 is less power at the lower RPMs, more power at higher RPMs. Also generally recommended is upping the jets a size or two. Add some indy intake filters to match the increased and freed up exhaust flow and up the jets again. There are tips in the tips section and several discussions about this.

I have a ceramic coated 4-1, I purchased my XS with them, so I have nothing to compare it to. I am somewhat sure the PO did not change the jets. I also have 4 K&N indy filters, which also were on there when I bought it. I have never ridden anyone else's XS, so mine might be a fine bike or a slug. Plugs get bit black by the end of the summer, not 'fouled' exactly, and clean easily with a wire brush. But I have been known to short shift (as in following TC through a corner, he's in second and I'm in 4th). It runs great, gets me where I want to go.

[Dan Hodges]

How Hard does V-Max pull

Ben aka Ae7f ask how hard does Mr. Max pull. The only thing I can think of that comes close is when my first wife pulled my bank account and left, now that's pull.

[Shuriken]

I have searched for 4-1 info on the board. It is a bit scattered, and I'm not the best with the XS11.com search engine....

What might be helpful for a common thread like this would be to archive a bunch of messages and place them in a common file.

When I first got an xs11 4 or 5 years ago, I archived everything that had personal relevance to the problems my bike exhibited - and used that information to fix the problems.

Perhaps I should start archiving exhaust threads.

I wonder why 4-1 = "less" hp at low rpm and more at high. Ah well, I'm one who likes to rev the bike anyway. The "lug" is nice with my '80g around town and when pulling the lady.

I have only ridden 4-2 pipe setups, so I will be able to chime back with what I perceive to be the differences.

Ben

p.s., you're right, Dan, that IS pull. I rode a V-Max once that pulled only slightly more than the XS. I think it was a messed up Max or I would have come back with the ear-to-ear smiley.

[MartyA]

"... wonder why 4-1 = "less" hp at low rpm and more at high."

As I mentioned, I can't even compare my ride to another, let alone my 4-1 to any 2-1 setup. I suppose the exact method would be a dyno run before and after. I don't recall ever actually seeing that, so I would say the statement is mostly 'feel' on the part of the owners who did change from 2-1 to 4-1.

Upping the jets seems to be the standard thinking, until recently someone posted that they went down a jet size to make his bike run better.

Denny Zander has some good info here on jets


Certainly let us know how it 'feels' after the change.

[grifff]

...

Ben,

Hello again. I couldn't tell you about the difference in the pipes, or why 4-1 perform better. I posted a thread awhile ago about this. I still dont understand why and how the 4-1 are better, whether at low RPM's or high. Be nice to get a detailed answer about how it all works. My bikes about all painted except for that darn left cover still can't find. I'm getting a new 4-1 exhaust prob a Mac system. They claim you dont have to take the pipes off to get to the oil filter. I have the oil cooler on my bike. It makes the filter sit a little lower towards the pipes. Anyways i do have the old set of 4-1 laying around. Headers are in very bad looking shape(no chrome). They look like the pipes under my RX-7. Dennis Kirk has the chrome 4-1 Mac pipes for around 350. Hey come by this weekend. You'll have to check out my Green Bay tank, it looks good. 646w 1350s in RockingHorse subdivision. I always have beer by the way

[Shuriken]

I certainly will add my feedback after I evaluate the 4-1.

Griff, I will definitely come by. I have to see that tank.

Ben

[Jerry]

Several books have been published on exhaust system design that go into depth on why 4 into 1 system perform better at some RPMs and not as well at others when compared to a stock 4 into 2 system.

Mostly it has to do with the timing/tuning of exhaust pulses. A well tuned system will use the exhaust pulses to draw more air/fuel mixture into the engine, thus the need (often) for re-jetting the carbs.

Advantage is more power, but often through a narrower power band. 4-into-1 system are lighter than the 4 into 2 systems as you loose the weight of the 2nd muffler. Combined with a different and exhaust note and looks, many people prefer the 4 into 1 set-ups.

I went the other way, went with a 4 into 2 system (Jardine) as I like the "classic" look of the twin muffler set-up. I use my XJ for comuting and towing a small trailer. Low-end torque is usually better with the 4 into 2, and that is important to me. (The crossover pipe, common on 4 into 2 systems, is normally associated with improved lower-end performance.)

In short, the difference in performance you feel will depend somewhat on your riding style. If you are replacing a crappy system with a good quality one, either a 4 into 1 or 4 into 2, you are likely to see quite a bit of improvement. Make sure you replace the exhaust system gaskets when installing the replacement pipes.

[grifff]

...

Jerry,

Hmmm, i was looking to get the 4-1 Mac pipes($350). They are cheaper than the Jardine($425). Mac claims you can get to the oil filter cover off without taking the pipes off. I have a oil cooler, do you know if you can get the oil filter off with either the Mac or the Jardine without taking the pipes off? And do you know if there is much difference in performance between the Mac or the Jardine, or is it just the name? You got me thinking about 4-2, ahh i don't know. Taking the pipes off to get to the oil filter kinda pisses me off though.

Griff

[TopCatGr58]

Hey there Griff,

Haven't done much research on this, but the Mac's 4-1 state they provide clearance for changing Oil/filter and Centerstand use! The Jardines don't say anything about it in the DK catalog. and the pictures of the headers looked like they are bunched together down the middle/ in front of the engine near the oil/filter chamber. I also remember a few folks mentioning that they had the Jardines, and that they had to remove them to change Oil/filter.

Now, if it's a 4-2 system, then I would "think" that each pair of headers would be swept towards the outside, allowing room for access to the oil/filter, but stranger things have happened!!

My old 4-1 were JCW's(not sold anymore), same ones as on Marty A's. It has a W-I-D-E power band, from 3.5k thru 8.5 K, I really can't tell if it's lost anything below 3.5K since it was so long since I rode it with stock pipes!? But was out today after a wash, to fill the tires up, and was tootling along at 20mph in 1st, and decided to crack it, pulled the front wheel up nicely, a good foot or so before I let off of it!! Y P(erformance) M V

[MartyA]

I never knew what mine were, no name or logo on them. They have a ceramic coating, and yeah they are starting to pit. I thought mine were Mac's, but what ever they are, yes, you can have your center stand and change the filter without removing the header. On the other hand, the oil drains on the pipes. Usually I fold a piece of aluminum foil over the pipes, but if I miss a bit it wipes right off. And the center stand sits about 1/2 - 1" lower in the up position. I do recall some Jardines don't have the filter clearance. Those spaghetti looking criss-cross Jardines have the clearance, if I recall.

In the upper gears mine does pretty well at about 3 grand or so, right up to 7,000. I have never been above 7,000, don't even know what it sounds like. Guess I will have to ride closer to TC...

As far as the difference between MAC and Jardine, once each cylinder's exhaust pipe length is established, they can take on almost any appearance. I think it was Mark Stanton with his shiny criss-cross 4-1 Jardines in WV? They should be identical in performance to my MAC wannabee JCW 4-1. The principle of headers like these is to get each exhaust pulse entering the collector just in front of the next one, and just behind the one in front of it. So some of the header pipes have a different length, and they all meet at the collector. That's what gives you the good scavenging effect, better than a stock 2-1. No pulses should collide at the collector, or you would be creating back pressure. 2-1 headers are made so that each set of 2 header pipes takes the pulses from 2 of the cylinders out to the back in good order. But the scavenging effect is lessened, due to the fact that the 2 pulses are further apart than the 4 pulses of a 4-1.

Something like this:
2-1 ___/\___/\___/\___/\__

4-1 /\_/\_/\_/\_/\_/\

Each pulse pulls and pushes, but with the 2-1 each pulse pulls and pushes more gap than nearby pulse - less scavenge. Depending upon the design of the 2-1 exhaust, there might be some unacceptable or unpleasant resonance from those gaps at certain RPM, so a cross over pipe (or in the case of my Venture, a big honkin' cross over chamber) is added to sort of break up the pulses a bit. That is why Harley Dave's straight through no cross over dual exhaust set off Deena's voice actuated radio when she was following him, and why TC's 4-1 exhaust has a pleasant 'buzz.' (Well, OK, BUZZ!)

There's lots more to it, bends, diameter, length to collector, collector design, muffler type and length, and whether it matches up with the necessary back pressure, carbs tuned for less or more back pressure, cam timing and lift and dwell, and on and on.

Well, that's about all I remember from my muscle car days of 35 years ago.

[grifff]

...

Nice, between Jerry, TC, and Marty i think we got a good understanding going on. Seems to be a little more complicated than it seems. My old pipes have no markings on them. I think i will go with the economical Mac 4-1. TC, it would be nice to take your bike for a spin. Sounds like you have a rocket.

By the way special covers wont work on a standard. They have a diff shape. Still looking for a 80G left side cover that mounts with holes on top. Ben came over other day thought about stealing his hehe.

Griff

[Jerry]

Most in-line 4s have the same firing order, 1-2-4-3. I think the XS/XJ is the same. The Jardine systems criss-cross not so much for cosmetic reasons, but to even the exhaust pulses out of each side. Stock system has 2 quick pulses (1-2 or 3-4) then a gap while the other cylinders fire and exhaust out the other side. (#1 left, #2 left, #4 right, #3 right)

Since the Jardines tie 1 - 4 to the left and 2 - 4 to the right, you get alternating pulses (more evenly spaced) from side to side. Theoretically this should improve scavenging. (#1 left, #2 right, #4 left, #3 right.)

Some folks don't like the 'busy" look of the Jardine cross-over, but they seem to work well. FWIW, on my XJ's Jardine 4 into 2, oil chage is no problem. I did have to notch the engine guards on both sides, though, as the pipes are either slightly larger in diameter or swing out to the outside edges of the engine a bit more.

[Jerry]

Correction

Sorry, Jardines tie 1 - 4 to the left, 2 - 3 to the right, not 2 - 4 to the right as I stated.

[Robert Haller]

I have the Jardine 4-1 on my bike and I can remove the oil filter without removing the pipes and use the centerstand. From past posts it seems that the main difference between Jardine headers and MAC headers is that the Jardine's may be finished a little nicer. That's why I chose Jardine. Motorcycle Accessory Warehouse had them for around $300 when I got mine a couple of years ago.