Westtech turbo ZX-11

[ddahlgren]

A friend of mine has one of these with a blow through carb setup and I have never seen it just talked about it. Problem he is having is it blows the slides open on even verry low boost engine them goes fat asnd then lean as the bowls are now empty. West tech can't fix it from what i am told. I would think the carbs have to see boost everywhere float bowls etc. Does anyone know what carb mods would have to be in order to run this thing. It is a street bike with no big aspiration other than to run correctly. My thoughts were to supply boost to the bowls and the top of the slide chamber to keep the pressures equal along with the obvious boost comped fuel pump.
Dave

[k.h.]

The (now defunct) Aerocharger blow-thru systems came with Mikunis specifically set up for turbo duty.  Turbo Doc in Ogden, Utah might have an answer.  801/334-9140 is the number I have for them.

[StraightSix]

I know many people with blow-through carbs use a carb hat, so the carb sees boost pressure from all sides.  You can seal the carb too, but I suspect the fully enclosed method would be simpler.

[joea]

Dave, those generally end up with no carb mods,
they predominately end up running best with even
stock jetting..............and proper placement of float bowl
vents to manifold, in this case airbox I believe........

I know of a site that has a few folks on there successfully
running the Westech stuff.......I will try to find it and repost
here,   I even have a defunct turbo bike perodical that
has a an entire section of one issue dedicated to the Westech
turbo zx11 kit........how it is set up etc..........

I should be back in Rapid City tomorrow, will hunt for it,
and will also try to post here the website,  the Westech guy
should be able to be contacted as well........

Joe

[1212FBGS]

Ya gotta toss those vacuum carbs, you'll be beating yourself in the head. There junk for even an aspirated motor and useless with varying boost levels. Had the same problem with a GSXR1100 I bought. I installed a set of used Keihin flat slide carbs off of e-bay for $400 and never had a problem again. I got the stock Keihin GSXR jetting specs off of the Sudco web site, pulled the needle clip down to the bottom grove and kept throwing bigger main?s in it till she made a full throttle pass without rolling over. Then I started lowering the needle till it was drivable in the midrange. The new owner loves it. Toss those carbs!
Kent

[joea]

CV carbs can be the finest carbs for nearly any application

I know a few folks making 240-300 hp, blow through, and ending up NOT
changing mainjets...............

there is a reason even Yam on the R-1 went to a combination
CV section / fuel injetion section on one of their models....

Kent, you bet other carbs can work,  BUT he has a combination
that works very well when put together properly.........that is
how his kit is designed...........even flat slides wont work if
the rest of system is not set up properly.........

I remember when 33 smoothbores were so hot,  and have a drag strip
article that showed stock CV carbs off one of the newer at the time bikes
making better ET's than the aftermarket smoothbores on a built NA Suzuki
motor...........

Kent  ...........thanks for the bitchin clutch cover!!!!!

how are your projects coming??

Joe

[1212FBGS]

Hey Joe
My junks coming ?long. Shaken? the twin-engine liner down for B-ville. Popped a head gasket on the rear motor at the May meet and snapped a final drive chain last month. Should have it fixed/ ready for EM next weekend and all the bugs worked out. Hope to go over 300 this year. The P/P Busa will be ready as will Randy?s 500a/psbpg Honda. Dan may ride my ?57 Gilera 125 p/v. Got lots of stuff to take to the salt, just depends what?s ready and what?s blown up. Your welcome for the clutch cover should make maintenance easier for ya.
Yours in sport
Kent Riches

[firemanjim]

Dave,Aerocharger kit on my Buell came with either a stock CV or a Mikuni.Must run boost line to float bowl on Mikuni so fuel will feed at boost.Uses a smaller inlet valve/seat because it's now pressure fed.I have a set of CV carbs on my turbo FJ off of a Turbo Seca and they work well but are set to see boost pressure also.

[ddahlgren]

sounds to me like at a bare minimum he needs a electric fuel pump, bypassing regulator and boost comp lines going to the float bowls and regulator then. On the CV carbs does a boost comp line go to the top of the diaphram as well? or is that already vented into the main bore of the carb?
Dave

[joea]

damn near sure it vents to main bore.......
sorry, no carbs infront of me for a few days.......

like I said, I know many simply running one line/tube
to the plenum........takes care of float bowls and diaphragms......

like you have said before, I have been wrong before.........


Joe

[landracing]

and sometimes its just a pain in the ass..... blow thru carbs


jon

[RZ350]

Blow through carbs work very well when the float bowls are pressurized using a pitot tube, I use this setup on my ZRX1100, and have made 239HP with main jets one size larger than stock.

The rest of the carburetor circuits remain nearly stock also, so tuning is relatively easy....

I'm using the stock 36mm Keihins that came on the bike from the factory, the A/F curve is nearly perfect from idle to redline, and driveabilty is better than a stock ZRX.

Contact me if you want more information.

Troy