Topic: Lets talk custom exhausts

[Terry in Australia]

Is Jardine still in the business? Their quality was tops, chrome and heavy metal, good seals. They just weren't the best-performing pipes back then, but at 55 MPH no one noticed.

Yeah, or at least, they were when I bought the new pipe in late 2009 Mark. I also added a Power Commander and K&N filter, and picked up a handy 22 BHP and 30 foot pounds or torque, at the back wheel.

The baffle was a "competition" model and it used to set off car alarms as I rode past, so I bought the optional "Street" baffles which quieted it down significantly, there's nothing worse than riding with one eye on your mirrors for cops...............  

[RRRToolSolutions]

Oh Darn, I had a set of those turnouts I took off my bike. They came on the bike and I figured they would perform about as good as my bike looked when I bought it -

This is my $112 eBay K4 in Boss Maroon.....those pipes got trashed...

Gordon

[Retro Rocket]

G'Day Mark, that makes sense, Jardine still makes nice pipes, I've got one of their "Big Boss" systems on my Triumph Rocket III. I probably didn't ride my 750 over 65 when I had the turnouts (mine are probably Jardines as well as they're pretty old) on my K1, but they felt pretty good. Cheers, Terry.

Rafi, the collectors are designed to slide straight over the OEM headers in their original positions.

Is Jardine still in the business? Their quality was tops, chrome and heavy metal, good seals. They just weren't the best-performing pipes back then, but at 55 MPH no one noticed.

Never a truer word spoken and goes for several companies at the time trying to eek out a living on the back of the best selling bikes on the market. Sorry boys, but most of the aftermarket pipes available were #$%*. They were simply replacement exhausts offered to owners not willing to look after the original pipes. There were barely any dyno's then and only the bike magazines could afford to test pipes. (except Mark said he had the opportunity) I remember reading there were maybe three pipes that made any power over stock.

I couldn't agree more Brent...

[Lostboy Steve]

I was thinking of the old "turnout" exhaust that was quite popular "back in the day", the OEM headers were quite good quality and a nice bend, but the mufflers were crap and would rot out faster than an English sports car. You could buy the turn out "4 into 2" mufflers and just hack the rusted out OEM mufflers off, and shove the OEM headers into the mufflers, and voila! A decent looking exhaust system again.

I found one on eBay a few years ago and installed it on my K1, it worked fine on the (then) stock engine except it was way too loud, and I couldn't work out how to install some baffles into each "muffler", or I probably would have kept them on the bike. Cheers, Terry.

http://www.ebay.com.au/itm/Honda-CB750-K-Custom-Performance-Exhaust-Mufflers-Turnout-Chrome-/151091928662   

I have those on my 550. It had them when I got it. I jut had them blasted and hi-temp coated.

[Lostboy Steve]

G'Day Steve, the most common issue that keeps coming up with them is noise, probably because they are chromed after the baffle is installed and the pipe is welded up, so they can't add fibreglass packing. I quite liked the turnout pipe look on my K1, but the noise pissed me off and I couldn't come up with a solution to repack the baffles without cutting and welding them, which would have ruined the chrome.   

Mine sound really nice, and when riding with a variety of different bikes, its still the most quiet out of the bunch. I will say that my left one has a rattle that i need to fix from the baffle weld breaking inside. Like you sid there is no way to remove them with that 90degree end.

[Terry in Australia]

Never a truer word spoken and goes for several companies at the time trying to eek out a living on the back of the best selling bikes on the market. Sorry boys, but most of the aftermarket pipes available were #$%*. They were simply replacement exhausts offered to owners not willing to look after the original pipes. There were barely any dyno's then and only the bike magazines could afford to test pipes. (except Mark said he had the opportunity) I remember reading there were maybe three pipes that made any power over stock.

I don't disagree either Brent, though back in the day it wasn't a case of "not looking after your original pipes", the original pipes were horrible, as I said earlier, my mate Davey replaced the OEM pipes on his K2 twice before he gave up and fitted some aftermarket pipes, the OEM's just rotted from within. Davey was most meticulous in his maintenance regime, and that's probably why he got over 100,000 miles out of his bike. 

Same for the pipes on my KZ900, you couldn't stop those things from rusting, OEM replacements cost twice what I paid for a better 4 into 2 system. The pipe on my F0 with it's bulbous muffler reduced the lean angle to the point where I fell off going around a slow right hander when the muffler grabbed the road.

I guess what I'm saying is that there were lots more reasons for us installing aftermarket pipes on our bikes, apart from perceived performance benefits. I binned the POS OEM F0 pipe and replaced it with a black RC 4 into 1 pipe, and with bigger main jets and K&N pods, it "felt" faster, but in the end it was more about the look, the sound, and not crashing the bike whenever I threw it into a tight right hander.

I think the main reason that most of the aftermarket exhaust manufacturers flourished back then was because the quality of the OEM products were so poor. Nowadays folks replace their OEM pipes for better performance, or the look, or the sound, but rarely because the complete exhaust system rotted out a year after the warranty expired, as was common "back in the day"..........

[bwaller]

Terry, maybe it was unfair to blame 750 owners for not looking after their pipes. I have the original set from my K3 hanging in my shop. They are perfect except the chrome is nearly worn off and yellowed. I replaced them a few years ago. I always removed them to clean, plus kept the drain holes clear. They didn't need to rust away.

Likely their biggest enemy though was condensation build up from short rides and not getting hot enough to burn that off.

Someday I'll find a chromer who's about to empty his tank and isn't worried about carbon and re-do these pipes of mine.

[Terry in Australia]

I wonder if you could chemically flush them Brent? I had a chrome 4 into exhaust that was pretty tarnished so I took it to my chrome plater and he de-chromed it for me (so I could paint it) and he didn't seem too fussed about messing up his tank, I think he cleaned it first in his "pickling" tank? Cheers, Terry.  

[edwardmorris]

Lets get back to the topic for a bit here

Anyone have input on collectors? I'll admit I haven't done my due diligence with googling, but if anyone has any interesting articles/links or info, please share. We can limit it to a 4-2 collector design for now.

[seanbarney41]

Really not all that much collecting going on with a 4-2....4-1 gets a little more interesting

[Retro Rocket]

Really not all that much collecting going on with a 4-2....4-1 gets a little more interesting

Agreed, Look at cone engineerings site, they have some nice off the shelf collectors....not too sure about 4 into 2 though...

[Grinnin]

I'd say make it easy to open, change, and reassemble.  Don't expect to get it perfect the first time.

My CB750K5 came with a loud 4-1 and ran very lean.  I have had a lot of trouble finding quiet exhausts for this bike and for others, so I have built innards for different muffler shells.  This bike now has 750A headers with Emgo muffler shells and my own internal baffles.

I have cut open several mufflers to see what works OK.  I prefer baffles over packing so this may not apply directly to what you're doing.

Although my baffles are near-copies of others, I still needed to adjust the sizes of openings or passages inside.  That was much easier since I could easily get the internals out, modify them, and get them back in for the next test.  After a few tries of drilling out a passage or welding one smaller, I made new internals without patches.

For a different bike, a thumper, the USFS spark arrestor is the final restriction.  Adjusting the size of the arrestor makes a huge difference in sound and tune.  I'm sure it's not how you'll adjust your performance exhaust, but it is one possibility if you get the tune near-right and need something quieter.

There are lots of great posts in this thread with lots of theory that seems to be backed by practice.  After all that, I suspect you'll still get better results by going beyond what you assemble first.

Good luck and HAVE FUN!

[edwardmorris]

Thanks Grinnin, do you have any pix of your custom stuff to share?

My original design has undergone a major overhaul now. Cones are wider and larger, baffles are no longer one contiguous inner pipe, and there is an actual collector now. Will post up some prototype pix soon.