Quote from: burning1 on July 21, 2010, 01:45:06 PMYou could probably recover a lot of your lost top end power by installing a X pipe ahead of the mufflers.

No, it won't. 


The welds cracked before the stair climbing.  The stairs just finished tearing it all off. 
There's more vibration than you think.  I had booger welds, also.  No - I'm not nitpicking.  It's a really nice look, and I hope it works out well for you.
Your silencers are more open than mine, so maybe you'll have better performance.  Screw with that needle, though, and you'll have problems.  I think I stuck with 145s or so, 2 washers, and 2.5 turns, with lunchbox.  Gave about the best midrange, which is what I wanted.  The midrange isnt actually the problem, it's the top end.  Could have gone all the way up to 155's I really believe, and MIGHT have hit redline.  But, the bottom end is extremely rich, then. 
Installed a 14t front, and literally could barely tell the difference from a 16t. 

Don't stop, though.  It was one of my favorite things I tried.  Teaches you a lot, while everyone else is talking out of their anus. 

Quote from: Homer on July 21, 2010, 02:22:48 PM

Quote from: burning1 on July 21, 2010, 01:45:06 PMYou could probably recover a lot of your lost top end power by installing a X pipe ahead of the mufflers.

No, it won't. 

Don't stop, though.  It was one of my favorite things I tried.  Teaches you a lot, while everyone else is talking out of their anus. 

Elaborate, please.

Quote from: burning1 on July 21, 2010, 01:45:06 PM
From what I understand, the expanded volume of the Y-Pipe in an exhaust system creates a negative pressure pulse that helps to suck exhaust out, and fresh air in during valve overlap. You could probably recover a lot of your lost top end power by installing a X pipe ahead of the mufflers.

Very very interesting idea, that I could do....Hell I had a X pipe on the 5.0 Stang...And I know I have tubing around that I could fish mouth into the area right before the headers bend under the front of the engine, wonder if this has merit?

As for the under tail exhaust, I wanted to, but thought/think it was out of my abilities, if this doesn't work and I cannot get a handle on jetting, then I may try that as an option.

So, not having the bike running, and not having the torn apart carbs handy to see what the current jettting set up is, throw some numbers at me...I know I drilled out some cap/cover on the carbs, like 10 years ago when I put the Dynojet kit in for the Hindle Exhaust but other than that I have no idea just what I did, and what Im running, so some jetting numbers and needle suggestions would help. I'll get the current set up and post what Im running.

Again Guys, you have no idea how helpful your comments and suggestions are, thank you so much.

The more I think about the X-pipe / H-Pipe mod, doesn't a H or X Pipe just equalize the exhaust pulses and flow, rather than creating a venturi effect there by pulling the gases out?

Homer, I had planned, and now will definitely, grind down the welds a bit, and go over them with another pass, I don't take offe3nse to your, or any others comments, I look at it as a huge favor, going at something blind, sucks, having a head start using the experience of others who already went down the same road, is invaluable. The cans will be rubber mounted (4 total), with a very robust mount that will come off of the rear round frame cross over section that mounts the linkage, we shall see how it holds up.

Is Buddah still a source for Jets or should I go straight to SUDUCO?

Please, keep the feedback coming, I really really appreciate it.

Fry, I've never designed an exhaust, so I'm speaking purely on my understanding of the theory. My understanding is that the length of the header to the collector, combined with the exhaust diameter, is one of the most critical tuning components of an exhaust system.

My thought was that an X-Pipe could effectively create a collector, and then split the pipe back out so that you could still use a pair of mufflers. Basically creating a mini 2 into 1 into 2 system. You may need more of a choke point than the X pipe supplies however.

Again, it's a thought. I'd suggest running it by someone with more exhaust design experience.

Quote from: burning1 on July 21, 2010, 04:11:48 PM
Fry, I've never designed an exhaust, so I'm speaking purely on my understanding of the theory. My understanding is that the length of the header to the collector, combined with the exhaust diameter, is one of the most critical tuning components of an exhaust system.

My thought was that an X-Pipe could effectively create a collector, and then split the pipe back out so that you could still use a pair of mufflers. Basically creating a mini 2 into 1 into 2 system. You may need more of a choke point than the X pipe supplies however.

Again, it's a thought. I'd suggest running it by someone with more exhaust design experience.

I don't know, your theory and explanation sounds pretty good to me....But why create a choke point or rather more of one? Simply for Back Pressure?

I thought the more you could do to increase flow and volume, the better, I thought creating big areas of restriction were bad? I do think the X-Pipe Idea has merit, they way I think about it, it's more surface/pipe length, that potential, at least in length, could mimic the Hindle/Stk. Header Y Collector.

Damm, now I have to go out to the garage and mock up, work on a H-Pipe Crossover Tube, Thanks Guys, LOL....And I thought all I had to do was the mount, Damm You, All of you....Pics to follow, perhaps tonight.

Me:  Crossover doesn't help, I had one.
Talking anus:  Did I say crossover?  I meant length.  
Me:  Well, why didn't you say that?
Anus:  I don't have design experience, I dunno.
Me:  Well, I do.  Why are you talking?
Anus:  Because I want to win the internet.  

Best way to simulate midpipe length for belly-slung exhaust:


Ask around for jets.  If they'll let you return them or not.  Most shops have them, just standard Mikuni's.  
Rinse them with isopropyl alcohol to get the gas smell off, and just let it evaporate.  They never know the difference.  

You'll have better luck than me.  I made my own mufflers.  Almost the same inner core design, except I used a perforated restrictor plate to simulate midpipe backpressure.  Didn't work so great.  Open flow will work better, just not sure how well.  You gonna need BIG jets.
Gonna be exciting to see it working.  Hopefully you'll post a video?  Should sound good.  

Stock header with H-pipe crossover.  Chopped at the collector and welded there. 
When the welds cracked, the restrictor plate effects were eliminated.  I gained maybe 5 HP from the 10 HP loss.  Tore it all off and went to straight open - no noticeable gain.
Swapped to vintage Yosh - immediate improvement (power, sound, etc).

However, it WAS one of my favorite alterations.  It'll probably be yours, as well. 

Fry: bad choice of words on my part. I'm wasn't thinking of a choke point, so much as an incredibly short mid-pipe. The idea being to make the headers resemble the OEM unit as much as possible, back to the midpipe. From there, split it back out so that you can use the epic double underbelly exhaust.

I have no idea if an automotive X-pipe would function similarly to a collector, given the differences in shape, but hey, it might work, and worst case, you just cut it off and weld the mufflers back up to the exhaust header. The other option would be to use a proper collector and a Y-pipe to split it back out.

Quote from: Homer on July 21, 2010, 04:56:10 PM
Me:  Crossover doesn't help, I had one.
Talking anus:  Did I say crossover?  I meant length.  
Me:  Well, why didn't you say that?
Anus:  I don't have design experience, I dunno.
Me:  Well, I do.  Why are you talking?
Anus:  Because I want to win the internet.  

Ask around for jets.  If they'll let you return them or not.  Most shops have them, just standard Mikuni's.  
Rinse them with isopropyl alcohol to get the gas smell off, and just let it evaporate.  They never know the difference.  

You'll have better luck than me.  I made my own mufflers.  Almost the same inner core design, except I used a perforated restrictor plate to simulate midpipe backpressure.  Didn't work so great.  Open flow will work better, just not sure how well.  You gonna need BIG jets.
Gonna be exciting to see it working.  Hopefully you'll post a video?  Should sound good.  

Homer, I have no idea who Talking Anus is? I pulled the silencers a little further back, about an inch or so, pretty much the maximum that I can, all in the effort to get Length. STill not welded to the header pipe, got finalize my rear mount 1st, which I worked on tonight. You had a restrictor plate, I will have a small, 1" round perforated core, which I think will create a good amount of back pressure, as the exhaust Inlet area is huge 2", and it is forced to go through the perforated round core and out the smallish 1" outlet. Who the hell knows if it will work. In that Pic, my Cross Over Pipe would be slightly wider, not by much though. I didn't have any 1 1/2" Stock lying around, so I lost steam on that until I can buy some, I do think I'll try making the crossover pipe, Who the hell knows if it will work.

I just unpacked all my jetting stuff...Will make another thread for that, with pics so people can explain to me, what I did 10+ years ago, LOL/

Quote from: burning1 on July 21, 2010, 05:41:34 PM
Fry: bad choice of words on my part. I'm wasn't thinking of a choke point, so much as an incredibly short mid-pipe. The idea being to make the headers resemble the OEM unit as much as possible, back to the midpipe. From there, split it back out so that you can use the epic double underbelly exhaust.

I have no idea if an automotive X-pipe would function similarly to a collector, given the differences in shape, but hey, it might work, and worst case, you just cut it off and weld the mufflers back up to the exhaust header. The other option would be to use a proper collector and a Y-pipe to split it back out.

I meant a simple crossover pipe, not the x-pipe design....I will try it.

Fry, talking anus was supposed to be me. 

Quote from: burning1 on July 21, 2010, 06:25:14 PM
Fry, talking anus was supposed to be me. 

LOL....

And I see in the pic, that the Curvy Pipes will mimic the length of a stk system?

I suspect the curves are there to permit the exhaust system to have long headers, and still be packaged in the space available on that bike. If you check the Fiche for a Kawasaki Ninja 650 (which is either that bike, or very similar) I notice that it still has a collector ahead of the exhaust canister.

So... I re-read the previous comments and realized that I'm an idiot. It sounds like a big part of homer's problem was that the bottom end was way too rich, and nothing I've suggested would help with that.

I feel like an idiot everyday with this project, but I don't let that stop me, LOL....Keep up the advice, the more I have to sift through, the easier my life.

Quote from: Fry on July 21, 2010, 06:18:12 PMI will have a small, 1" round perforated core

Same here.
1" galvanized tubing, cut with v-slots bent into scoops toward the airflow and drilled.  2.5" outer body.  
Dissolved the galvanizing with hydrochloric acid, and boogerwelded it.  
Bracket welded onto outerbody.  Vibration tore it to pieces - rust in the stock collector ruined the welds, I think.  

Yes, the bottom end was way too rich.  Compensated with 6* timing advance (too scared to run further).  Still had troubles leaning out at 8500 RPM. 
Not to say you WON"T be able to.  It's possible.  I just didn't wanna ask anyone how.  I'm too hardheaded. 

Hopefully you don't think I'm trying to compete with you, here.  Yours will run better, because you're lacking restrictor plates.  That's all I meant to say.
The Kawasaki design incorporates more length, yes.  That's what I was trying to show you.  Their muffler upgrades have the same core design you're using, just a little larger to compensate for both cylinders being run through the same core.  Single out, with the muffler inlet acting as the collector.  But, that's with fuel injection/variable timing.  
The backpressure everyone talks about is ultimately a ratio of the volume of air behind the valves compared to before them.  At a certain ratio, it gives sort of a self-regulating Bernoulli effect.  Chop the ratio, and you've gotta make up for it with jetting/timing magic.  IMO, anyway.  I'm just an uncreative, bitter, immature jack@ss.  

Homer,

What I've read about exhaust design suggests that most of the critical tuning parameters revolve around the timing of a low pressure waive that's reflected back at the exhaust port. I presume that a muffler is designed to more or less trap and absorb any pressure waive that enters. So, wouldn't running a straight header directly into a muffler kill that pressure waive?

Quote from: Homer on July 21, 2010, 07:27:49 PM

Quote from: Fry on July 21, 2010, 06:18:12 PMI will have a small, 1" round perforated core

Yes, the bottom end was way too rich.  Compensated with 6* timing advance (too scared to run further).   

Hopefully you don't think I'm trying to compete with you, here.  

Dude, seriously, I feel your being nothing but extremely helpful, seriously...Learning by someone elses experiences is a great thing, your going to get me in the ball park, if at all possible. Without yours and others feedback, I'd be going at this totally blind and investing a S-Load more time.

Please, keep the feedback and suggestions coming.

Any special tools or parts for advancing the timing? Any pictorials?

Rat-tail file and a ruler.  Dremel takes too much material, too fast.
The how-to's around here somewhere.  I think it's like 3mm or so you need to take off.  Gives you like 6*, which is about all you want to run on the street. 
That's not valve timing, mind you.  It's ignition timing.  A world of arguments in itself.
Varying valve timing (modified cam lobes) works with the exhaust pressure modulation Burning is talking about, but only as a side effect.  See what I mean, though?  It gets complicated really fast. 

That's where all the magic happens.  Lots of fun to play with. 

The low pressure wave is relative to the contained volume that can contend with wave dissipation.  Sort of a Doppler effect, the high pressure/low volume coming out of the port versus spent lower pressure/high volume still in the pipe downstream.  When (and where) they combine and resonate is dependent on the volume held in the pipe.  That's why length and diameter matters, and where the choke point comes into play. 
The power advantage is in delaying the venturi effect.  As the high-pressure gasses exit, if you slow them just enough - they'll help drive the piston and complete combustion.  That's the "low-pressure wave".  But, the faster it exits, the venturi effect draws in incoming air by itself.  (Like siphoning gas)  (That's how the carbs pull fuel in, by the way.)
Get it just right, and the engine doesn't have to "pump" the air as much.  It just kinda does it itself, with an ignition point in between.