So I’m building up a track MC28 using all the various go fast goodies I’ve collected over the eons. I’m thinking of running a jha ram air system but wondered if I should use an MC21 card manifold with the boost bottles, or the mc28 one without. My thinking is the 28 had boost bottle, but attached to the std airbox which is no longer there. Any thoughts?
Hi Tom I have a few with bunged inlets and the Castrol bike has no boost bottles I don’t think they rely on them for performance enhancement,
Jonmac _________________ John
I think the Theory of "boost bottles" was the charge would have somewhere to go when the reeds are closed and not loose inertia, Was a big craze in the 80's but they diisappeared from bikes as quiclky as they appeared so you would guess they probably did next f**K all!
The strange thing with the Nsr is on the 28 they disappeared from the inlet manifold between the carbs and reeds and appeared behind the carb on the airbox intakes???? Very strange and know doubt still achieved F all!
Couldn't have put it better Paul, I remember back in the 80's, they were all the rage on trials bikes, and when you took them off there was no difference, I never bothered with them on my track 21. _________________ Proud Father of , 05 ktm 400exc supermoto 2018 honda crf rx supermoto
I think you'll find they are inlet resonators, and tuned to work at a quite specific RPM (or RPM range) to iron out certain harmonics. They're all but irrelevant for full-power WOT applications.
You will find similar resonators on all kinds of sports cars too. _________________ Andy.
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It was part of the 80's craze for gizmos and acronyms, Yamaha were big into boost bottles and called them YEIS if I remember correctly Yamaha energy induction system.
As I say, it's a roadbike (road car) thing. The car guys generally junk them because many sound better with it removed (more intake growl... then again, they're moving a lot more air), we junk them as they serve little to no purpose at the kind of throttle openings and RPM used on track.
I'm sure Yamaha and Honda, and Mazda, Toyota/Subaru, BMW, and Porsche, and many others, could produce a whole slew of technical information advocating their presence. (They're just the manufacturers that spring to my mind.) _________________ Andy.
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I'm sad enough to find this interesting, being that at least a relatively basic understanding [I'm no phD, after all!] of fluid dynamics is useful designing in hydraulics. I'd always been curious about the effects on the NSRs, but I doubt it's something even particularly measurable on the dyno, and we never had time to try it. (One of the few things on the NSR I don't have first hand results/graphs of, unfortunately.)
I am sure there's a reason why Honda moved it to the airbox/behind the carbs on the MC28. Maybe because the shorter carbs dictated it, maybe they found adding several cm to the inlet length worked better given the lower 40HP limit and the rev range the standard bike was predicted to run in. No idea... but I'd really like to know! _________________ Andy.
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paul g wrote:
It was part of the 80's craze for gizmos and acronyms, Yamaha were big into boost bottles and called them YEIS if I remember correctly Yamaha energy induction system.
Like this, you mean?!
_________________ Andy.
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paul g wrote:
It was part of the 80's craze for gizmos and acronyms, Yamaha were big into boost bottles and called them YEIS if I remember correctly Yamaha energy induction system.
Like this, you mean?!
Exactly like that, an acronym for evrything . My favourite was on the 1985 Yz range called BASS brake activated suspension system. The back brake had a spring attached to the Shock that changed the damping under braking to stop the back chopping about under braking. Most people disconnected it after the first ride and it was discretely dropped the following year
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. My favourite was on the 1985 Yz range called BASS brake activated suspension system. The back brake had a spring attached to the Shock that changed the damping under braking to stop the back chopping about under braking. Most people disconnected it after the first ride and it was discretely dropped the following year