mortymower

can someone explain to me the venturi's purpose, what it is, where it is, and the best way to remove, if that is even neccesary. Thanks

35thSLP

The venturi is there to create vacuum when you are on boost. It is also a great place to get a vacuum leak when the o-ring inside get hard. It is located underneath the intake manifold. Best way to remove it is to take the intake Manifold off and replace old vacuum lines while you are doing it. You also might consider installing a mannual boost controller (MBC) while you are at it so you can also delete the cycling valve.

jturbo

What does the Cycling Valve do?

TRACKIN951

The cycling valve is basically a boost controller. The computer tells it when to open and close. And from there the wastegate either is open or closed. I dont know how else to describe it so hopefully that makes sense.

jacklet

ditch both of them will make the p-gods and your car happy

xtaC

Any chance of some pics of the Venturi, as well as the cycling valve, as well as a step by step for deleting them both?

I have the Intake Manifold off at the moment, and am keen to clean some house

jacklet

do a search, get a vac. line kit updated idle stab hoses the aos hose you can get from napa somewhere i have a list of stuff and part#'s the vac. line kit is nothing more than some brass tee's and a bunch of vac line i used thicker walled silicone hose for that, the search will get you the info on the cycling valve delete and venturi. if your man. is off let me know i'll tell you what to do it's really simple and usually the car runs a lot better

2bridges

WOW - evrybody is so quick to remove Cycling Valve for no reason.....

here are a few considerations regarding deleting CV

CV is what facilitates 1.2bar 'limp mode' to "SAVE" your engine in the event of fault code. This is your safety net if boost/knock conditions get out of range. If you are not aware, preignition (knock) under boost especially will severely damage combustion chamber components(pistons,valves,head surfaces, etc) in very short order.

simply elimintaing CV without another means of knock protetion IS FOOLISH (to put it nicely)
Even more rediculous is to remove CV,then increase boost with MBC - I cannot think of a faster way to cause a meltdown in any turbo car

Increasing boost in any fashion requires full consideration of engine management changes,increasing fuel needs, carefull tuning and Air/Fuel status checking.

Dal Heger

I agree with 2bridges.

The CV/KLR system works well, and it IS the only safety net you have in the engine if you have a problem. I've seen first hand what happens with a manual boost controller equipped car (on a newly rebuilt engine no less) that had a lean knock condition in one cylinder. With no indication of being in safe mode (1.2 bar boost absolute) the owner found out he had a problem when the car started smoking badly. Turned out that the knock (under boost) was bad enough that he burned a hole through the cylinder wall. Basically destroyed a block.

no, you can't hear knock when the engine is boosting, the engine management is the only thing that will be able to save your engine when that happens. The ONLY indication that you get that something is wrong is when you get put into "safe mode". The ONLY indication you are in safe mode is that the KLR - via the CV (boost control) limits you to only 1.2 bar absolute.

Remember, these cars have no "check engine" lights.

I still stand by my statement that removing the CV and using a manual controller is akin to playing with fire. You might be lucky, but sooner or later, you'll get burnt.

Dal.