Manifold/throttle bodys-ED:-)

[Stuart Baly]

>Does anyone know what would happen if you joined all the chokes 
>together on the down-stream side of each throttle, kind of like 
>forming a mini-plenum for improving balance robustness at low throttle 
>openings, but still allowing the correct runner design and plenum 
>volume up-stream of the blades for WOT performance?


Yamaha also had another version of this apart from YDIS - I can't remember 
it's name but its used on the Yamaha V-Max. The engine is a 1200 V-4 with 
four downdraught carbs in the V. At high revs two butterflies open to join 
the intakes in pairs across the V. The idea is that the cylinders in each 
pair are drawing in air at separate times, so each cylinder can use two 
carbs rather than one. I don't know if it made that much difference to 
power, but a 145hp from a 1.2L engine is alright.


Stuart


P.S. All this talk of knock reminds me...

One Sunday night recently I went for a ride in a Daihatsu Charade with a 
friend of mine. She said "Hey, listen to this!" and accelerated out of a 
25mph corner at full throttle in top gear, knocking like a dog (the car, 
not the driver) all the way to about 50mph. She was laughing all the way, 
and said "It sounds like a truck!". I asked her how long she'd been doing 
that, and she said "Oh, most of the week."! These Daihatsus are tough 
little cars.


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             Stuart Baly (S.Baly at BoM.gov.au)
'71 Datrat 1600, '89 Kawasaki GPz900R, '81 Yamaha RD350LC
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