Topic: yoshi exhaust

[kos]

I bought a new 4-1 from Mark at M3. He assured me it was an exact copy (only better engineered) of the genuine Yoshimura pipe that he owns. Isn't this the case Mark? (Phil Clark, Woodbridge, UK).

Phil...Yes, You have a very well engineered exact copy of the hand bent Pops' pipe. Yours is much better in it's finish and fit than my real Pop's pipe.


Mk@m3

[kos]

it looks to me the reason there aren't more decent exhausts and other parts for our bikes is that there aren't enough of em left to make it worthwhile to the manufacturers. they love the harley/cruiser crowd and the plastic sport bike crowd too because theres so damn many of em.

Your exactly correct in your assumption RE: not enough customers out there that want well designed, Hi-perf pipes for Hon SOHC's. Talked with Lang Hindle, from up in Canada, once at Daytona and asked him to build me some pipes.  His reply...threw out all the jigs he had, because they take up too much room in his facility and unless I order a thousand...was not worth his efforts.

He made a great pipe for CB750's.

KOS

[paddy paul]

Phil, How much was the M3 pipe? cheaper than the yamiha?

[wannabridin]

i highly doubt that.  he doesn't even advertise them on his site, probably a limited run or one off.  i'd reckon $1000+, i'll be VERY surprised and interested otherwise, haha!

[Rod]

I think there are two concerns about striving for the 'Prize' of a Yoshi exhaust. Firstly, as others have mentioned from time to time on this site, things have moved on from Pops day: he did not have access to the materials and computerised design/diagnostics available to engineers today, and exhaust design is one area that has benefited especially in this regard.

Secondly and more importantly (I'm sure Pops would have agreed), performance exhausts should never be considered another 'bolt on' part in the tuning project. There is no such thing as a generic 'race' exhaust, i.e. one that simply makes all tuned engines of a given type go faster, thats a myth that sustains the lucrative aftermarket for street-jockeys. When Pops designed his exhausts, he will have done so taking account of all the detailed Yoshi tuning, mods and wizardy that had been done to the internals, plus carbs and setup etc. Which means if you have a complete Pops engine and setup then the Yoshi exhaust is made for the job, if you dont............

An interesting website put it much more succinctly; when it comes to exhausts, don't think Parts, think Package       http://www.rbracing-rsr.com/exhausttech.htm

Hope I'm not being too controversial here.
Rod

[MRieck]

it looks to me the reason there aren't more decent exhausts and other parts for our bikes is that there aren't enough of em left to make it worthwhile to the manufacturers. they love the harley/cruiser crowd and the plastic sport bike crowd too because theres so damn many of em.

Your exactly correct in your assumption RE: not enough customers out there that want well designed, Hi-perf pipes for Hon SOHC's. Talked with Lang Hindle, from up in Canada, once at Daytona and asked him to build me some pipes.  His reply...threw out all the jigs he had, because they take up too much room in his facility and unless I order a thousand...was not worth his efforts.

He made a great pipe for CB750's.

KOS

You actually told me this story years ago during a phone conversationas I told you I was running a Hindle on my CB

[paddy paul]

No matter what exhaust I end up using, I understand that it's part of the overall "package",carbs, proper head work, Cam, pistons, etc, But I think one of the keys to the SOHC'S is the fuel/air issue, more fuel,more air, more HP..

[Don R]

Maybe a california member could roll by Performance Welding Racing Headers, they are in Foresthill. Not sure where that is but they build an awesome stainless drag race header. I got a set of 2 1/4 x 2 3/8 stepped, stainless, polished with merge collectors for $1100 for my dragster, thats for two, twice as big as honda pipe. Most shops get $2600 for a similar pipe. Just a thought.

[Phil]

RE: my 4-1 from M3 Racing. It is very well made and finished. It fits at the cylinder head perfectly. It certainly looks like a Yoshimura product but doesn't have those flowing bends of the hand-built Yoshimura pipes. I don't think the production Yoshimura pipes had the sweeping bends either. I haven't run an engine with this pipe yet. Cost? Not unreasonable! There would be no problem, I'm sure, of precisely replicating a hand-built Yoshimura pipe. There are more who can do this work than Rob North! (Not to belittle Rob North's amazing work but I know a guy who built the original factory Rob North frames for BSA/ Triumph. He told me they didn't have a jig back then (everyone was slightly different) and they bent the tubes around a tree outside the workshop! He still builds the RN replica frames and now uses a proper jig and says they are much better!) There is a firm in South Wales (I think) that builds exhausts for race cars including F1, WTC cars etc. Some of these are truly amazing pieces of engineering and a Yoshi pipe would be well within their capability if they had one to copy. Remember, Pops bent them by hand!

[kos]

A guy who built the original Rob North frames?


Rob North built all of the original Rob North frames. The only thing he did not do correctly was to stamp sequential serial number them... as to differentiate form those who came after him. Everything after Robs originals are just replicas.



KOS

[754]

If Pops hand bent the pipes, then there is probably no standard, they are probably all a bit different.

[turboguzzi]

small trivia question.....

Who was first out there with a race 4-1?

The first production bike was the CB400 Four me thinks, but who actually tried it first at the track and when, yoshi?

not that i know the answer, just curious

TG

[voxonda]

Well I think it actually was Yoshimura who first raced with the 4 into 1, was a controversy between him and Honda who used the 4 megga's, the Yoshi's were faster. Not always more reliable but faster.

[cb750k77]

i've got an idea why not find some cheep old Kerker 4-1 headers and put this carbon fiber muffler on it

[Phil]

Dave Degens (of Dresda) claims to have made the first 4-1. He told me he did it simply to improve the ground clearance and them discovered it improved mid-range power. Whether frames or exhausts, most genuine race parts were hand-bent in those days and no two were ever likely to be identical.

[MCRider]

I think there are two concerns about striving for the 'Prize' of a Yoshi exhaust. Firstly, as others have mentioned from time to time on this site, things have moved on from Pops day: he did not have access to the materials and computerised design/diagnostics available to engineers today, and exhaust design is one area that has benefited especially in this regard.

Secondly and more importantly (I'm sure Pops would have agreed), performance exhausts should never be considered another 'bolt on' part in the tuning project. There is no such thing as a generic 'race' exhaust, i.e. one that simply makes all tuned engines of a given type go faster, thats a myth that sustains the lucrative aftermarket for street-jockeys. When Pops designed his exhausts, he will have done so taking account of all the detailed Yoshi tuning, mods and wizardy that had been done to the internals, plus carbs and setup etc. Which means if you have a complete Pops engine and setup then the Yoshi exhaust is made for the job, if you dont............

An interesting website put it much more succinctly; when it comes to exhausts, don't think Parts, think Package       http://www.rbracing-rsr.com/exhausttech.htm

Hope I'm not being too controversial here.
Rod

More on RB Racing here. http://www.rbracing-rsr.com/aboutrb.htm
He (Rob Banes IIRC) actually did other stuff before Harley. I have a hand made CB750 pipe of his that is supposedly a knock off of Honda's B'ol D'or pipe. Used it on my roadracer and later on my 888 street bike. Seemed to work really well on both. I was able to tune out all popping and flat spots, which is hard to do often. It is not a monument to beautiful bends but rather a series of stratights and bends all welded together. No compromise for street, couldn't use the centerstand and had to remove it to change the oil. It had total ground clearance though couldn't scrape it even if you fell down. Hope to use it on my cafe racer project.

[turboguzzi]

Dave Degens (of Dresda) claims to have made the first 4-1. He told me he did it simply to improve the ground clearance and them discovered it improved mid-range power. Whether frames or exhausts, most genuine race parts were hand-bent in those days and no two were ever likely to be identical.

Cool but when did it happen? Trying to figure out also when was the system seen first.

BTW, Honda's very own 1975 CB500R endurance racer already sports a 4-1, so the time window must be between, 1972 and 1975. Dont remember ever seeing a race CB750 sporting a 4 -1 before 1972, but i might be wrong.

TG

[Jerry Rxman Griffin aka MuthaF'er]

it looks to me the reason there aren't more decent exhausts and other parts for our bikes is that there aren't enough of em left to make it worthwhile to the manufacturers. they love the harley/cruiser crowd and the plastic sport bike crowd too because theres so damn many of em.

Your exactly correct in your assumption RE: not enough customers out there that want well designed, Hi-perf pipes for Hon SOHC's. Talked with Lang Hindle, from up in Canada, once at Daytona and asked him to build me some pipes.  His reply...threw out all the jigs he had, because they take up too much room in his facility and unless I order a thousand...was not worth his efforts.

He made a great pipe for CB750's.

KOS

Perhaps you boys have seen the NOS Hindle 4 into 1 on EBay?!

[turboguzzi]

from yoshi's site....

"1971     The first prototype 4-1 exhaust system was introduced by Pop and tried on CB750 in Ontario 250."


can anyone confirm?

TG

[754]

I am thinking Russ Collins was building 4-1s by 70 or 71.., not 100 % sure on that..

By the end of 72, there was at least, 6 or 8, if not more manufacturers.

[MCRider]

I am thinking Russ Collins was building 4-1s by 70 or 71.., not 100 % sure on that..

By the end of 72, there was at least, 6 or 8, if not more manufacturers.

I had the TripleA in my avatar no later than Oct 71. It wasn't the first available. Yosh may have been first but not by much.

[754]

Looks like RC was making them in 70 or earlier..

 Got to be the most made, by the most makers, part for any Honda..

[kos]

Pop's probably was the first, but George Kerker always claimed he was first, but so did Russ Collins of RC Engineering. Also Jim Dickerson on of Action fours was talking like he did it first. Here is a picture of Gary Fisher's bike at Sears Point, Ca 1971...lookes to me like a hand bent, four into one!

I'm pretty sure Dave Degen's was not the first. They did not even sell CB750's in Europe until 1971.



Also, look at the craftsmanship of the bike...NOT!  Look at those welds! Can you say, arc welder!!! Yikes, I can't believe it made it thru tech?


KS

[kos]

Well I think it actually was Yoshimura who first raced with the 4 into 1, was a controversy between him and Honda who used the 4 megga's, the Yoshi's were faster. Not always more reliable but faster.

No Honda did not make a four into one until early 1973 at their comeback effort at Daytona on Sumiya, Riemann & McLaughlin works bikes.

There is a bit of a story to tell here....Jim Dickerson an ex-American Honda employee and the guy who caused a fit over the four individual carb cables in Ko's sticking and causing the first recall in motorcycle history to be issued. He went off and started Action Fours in Southern California and kept challenging Honda guys to a drag race with their Works 1973 bikes with four individual megaphones on them against his Action Fours street bike with four into one. Guess who won....the Action fours bikes, by a wide margin! Honda immediately built up some four into ones for Daytona event.

Trouble is, Jim never told Honda that his bikes were "BIG" 836-900cc's or something like that.


KOS

[kos]

Also, it is general agreed that Triumph made the first collector exhaust for motocycles on their fabulous 750 Triples. 3 into one.


KOS