[Diy_efi] Venturi effect crankcase breather

[Matt Porritt]

On 10/7/03 7:05 PM Adam Wade wrote

> --- Matt Porritt <porrittm at anet.co.nz> wrote:
> 
>>>> Not quite magic, but a vacuum gauge easily shows
>>>> there is vacuum.
> 
>>> I suggest you test this teory at some point.
> 
>> Like me to start one of the many vehicles here and
>> photograph the vacuum shown on gauge?
> 
> Between the atmosphere and the throttle?  Yes, I'd be
> delighted, although I am sure you will be saddened by
> the performance of such a vehicle.

Hold on here. Vacuum at plenum you said, not you've brought in
'throttle-atmo' obviously not vacuum (not measurable on any gauge I have
here anyway)

> 
>>> Since a PCV line has to connect to the intake
>>> BEFORE the throttle, no, it will eseentially be
>>> indistinguishable from atmospheric.
> 
>> Hang on a second.. 1 minute you're taking about no
>> vacuum at the plenum, now PCV before the throttle?
> 
> There is no PCV at the throttle.  IT always happens
> before the throttle.

I'll post pics of PCV line AFTER throttle if the site will take them.

> 
>> Does it not matter which side the throttle is on the
>> plenum?
> 
> Matters to the plenum, and to throttle response.
> Doesn't matter with a PCV connection, since they are
> always upstream of the throttle.

No always upstream of the throttle (refer to above pic offer)
I won't make a statement on throttle position in relation to plenum, just an
opinion that on a multi throttle 2l turbo engine, moving the TB to pre
plenum does nothing as far as drivability goes other than to give a smoother
vacuum reference for tuning.

> 
>> Hmm.. I'm looking at a PCV line that connects AFTER
>> the throttle here at the moment.
> 
> That would essentially create a vacuum leak.  What
> vehicles have such a setup?  I've never seen one
> before.  Without a way to measure the content and rate
> of flow into the engine from such a port, there's no
> way you could accurately fuel the engine.

On a NA car yes, but on a turbocharged car (I'm stirring the shit now ;)



> 
>> Read what you wrote that I replied to.
> 
> I have.  It's not terribly coherent.

Exactly what you wrote. ;)

> 
>> I spend 10hours + a day under the hood of
>> performance vehicles.
> 
> Maybe you should learn how to work on the, so you
> don't have to spend so much time on them.
 
My time under them is spent extracting power, putting them in chassis that
they wern't designed for and forced induction.


_______________________________________________
Diy_efi mailing list
Diy_efi at diy-efi.org
http://www.diy-efi.org/mailman/listinfo/diy_efi