Blow thru turbo info

[Booster]

Found this on other sites and figured it may be a help to anyone looking to blowthru carbs in std position.
Pressurize Carburetor

To get your vacuum carburetors to work with Turbo you need to pressurize them

You need to pressurize above and below the diaphragms

You also need to pressurize the flout bowls

This instruction is for the R1, but the principle is the same on all vacuum carburetors

My carburetor setup is stock except Needle down one clip (leaner)


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Pressurize diaphragms

Above the diaphragms

On the R1 you have two holes in the slide that will pressurize the top of the diaphragms.




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Pressurize diaphragms

Below the diaphragms

Static pressure

To get pressure below the diaphragms you need to connect a tube to the vacuum air vent for the diaphragms

You need two tubes, one for carburetor 1 and 2, and the second for carburetor 3 and 4

Connect this tubes to the plenum camber




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Pressurize Flout Bowls

Dynamic pressure

The tubes should be mounted to the air ventilation for the flout bowls (The thin tube in the picture)

You need two tubes here also one between carburetor 1 and 2 and the second between carburetor 3 and 4

Connect this tubes to the pitot pipe on the plenum camber

The pitot pipe creates the Dynamic pressure




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Connect to Plenum camber

To pressurize your carburetors connect them to the plenum camber



New picture, click to enlarge

The small hole in the pitot pipe that's goes through the big pipe is 4,5 mm
The small pipe is 8.mm inside 10 mm out side
The big pipe is 45 mm inside

The small hole in the pitot pipe has to be in the middle of the big hole

[Booster]

And anothers experiance after doing as posted above.

i have the same pilot hole set up as the r1 carb set up that is on this site,
the fuel reg is tied in the same line as the float bowl,
i have checked the fuel pressure and the flaot bowl pressure,
7psi boost , 11psi float bowl air pressure, fuel pressure 15psi.
under load and with 7psi boost the a/f ratio is 12.2 to 1.
idle and cruise is good .

now for the problem! when taking of from a standstill the mixture will
drop to 10 to 1, the bike will run like poop, i believe this to be from
the pilot system starting to pressurise the float bowls and richening
the fuel ratio. i have vented the float bowl line to atmo and the take off problem goes away. (carb set as follows 120 main jet, needle set
to lowest position, otherwise std carb for fzr1000).

And his fix.

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fixed the carb problem.
seems the float bowls were being over pressurised.
adjusting float bowl pressure by the way of a brass t peice in
each foat bowl line and a 0.9mm restrictor i have bleed some
pressure back to the plenum.
hole size was set to bring idle back to pre turbo mixture
idle a/f is now 15-1
cruise a/f is 14.2
full throttle is 12.2 at 7psi
quick throttle operning see's the mixture drop to 11.8 then come back
to 12.2 -1 under boost.
Was getting mild detonation around 6000rpm
set up a water injection system, hobbs pressure switch , fuel shut
solenoid and winscreen washer bottle. This is triggered at 3psi boost
and injects water at the turbo inlet thru a .020'' hole. no more detonation!

[Deano]

so where are the pics?

what is the link to the site that the first comment came from

i just read the second commeent on OSS

[Booster]

[:I] Sorry forgot the pics wouldn't cut and paste
http://www.turbo-bike.net/.