03/04 Cobra Vacuum Lines Documented

[mwolson]

I have been apalled by the lack of documentation regarding the vacuum and boost lines for the 03/04 Cobra. I am collecting parts for a Teksid Terminator motor I am slowly building for my 96 Cobra, so I have most of the lines and parts in my collection.

A friend asked me to help with getting his 96 Cobra 03 conversion working, including helping him to debug a screwed up vacuum system. As a result, I decided to document the stock 03/04 Cobra vacuum/Boost Line setup.

I have created a 9 page pdf document here: https://accutach-public.sharepoint.com/Pages/TerminatorEngineHarnessSwapR1-4.pdf

EDIT: I have attached the pdf to this post. MWO 5/1/17

Please take a look at it, and tell me if I have made any mistakes. Also, there is a capped Y fitting where the harness plugs into the intake pipe. I have seen pictures on the internet of a black line that goes to the capped fitting, but I have no idea where it goes in the car. If anyone can tell me, please do.

Thanks for looking at this and for your feedback.

 

[mosconiac]

About 5 years ago I ripped all the plastic tubing out & replaced it with Earl's stuff, so I have some (dusty) knowledge of where everything goes. If you get a chance, compare your pdf to my files HERE. I drew everything out in MS Paint. LOL

 

[03cobra#694]

Goodstuff, saved for future reference.

 

[mwolson]

About 5 years ago I ripped all the plastic tubing out & replaced it with Earl's stuff, so I have some (dusty) knowledge of where everything goes. If you get a chance, compare your pdf to my files HERE. I drew everything out in MS Paint. LOL

Nice artwork. I drew mine with MS Visio.

I think you are missing the supercharger vacuum reservior and check valve that ensures there is always vacuum so the PCM can actuate the boost bypass valve any time it wants to. The way yours is hooked up, if the PCM tries to dump the boost when there is no vacuum, the boost bypass valve will not work. I suspect this just causes a slight delay when you drop off full throttle for some vacuum to build, so your bypass may open a little slower than stock.

I am not sure it is a big issue though. If you read this thread on how to eliminate boost drop-off, http://www.svtperformance.com/forum...-boost-drop-off-eliminate-boost-solenoid.html, you can see that they eliminate the vacuum reserviour and boost dump solenoid entirely.

Everything else you did is consistent with my drawing. And you have pictures of the Evap System under the fender. Very helpful. Thanks!

 

[kmadona]

Good info. SAVED

 

[mwolson]

Thanks to Mosconiac, I was able to add more detail about the Evap system in the fender, so I updated the document to Revision 2. Download it here: https://accutach.com/Documents/VacuumHarnessSchematicR2.pdf

 

[mmustangsrus]

thanks bro :rockon:

they should sticky this in the terminator section !!!!!


OOPS !!!!! it is in the terminator section LOL

 

[jrgoffin]

Great info, thanks!!!

 

[exdeath]

What's with the T in the PCV going to the lower intake manifold vs the diagram that shows a oil separator and "IPS"? WTF is IPS?

 

[timspony]

Very good info!!! ...Thanks

 

[SVTkel]

A good thread.thanks

 

[Evil Bender]

Great info! Thank's for taking the time to do this .

 

[mwolson]

What's with the T in the PCV going to the lower intake manifold vs the diagram that shows a oil separator and "IPS"? WTF is IPS?

I figured out that the "IPS" is the Intake Pressure Sensor" integral to the IAT2 sensor.

Regarding the T and the oil separator, here is my theory: When the engine is at idle or part throttle, there is about 22" of vacuum in front of and behind the blower (upper and lower intake), so air is flowing from the air intake pipe, into the passenger side valve cover, down through the crankcase (where it picks up oil vapor), up through the PCV valve in the driver's side valve cover, and through both sides of the T into the upper and lower intakes.

The way an oil separator works is that the oil separator is a wide spot in the PCV hose. When the air goes from the narrow hose to the relatively wide oil separator, the air pressure drops (from the Ideal Gas Law). When the pressure drops, vapors start to condense into drops and the oil drops fall into the separator. This is that same reason we see rain in low pressure atmospheric conditions.

The intake manifold represents a really wide spot in the PCV system, so when the oily vapor hits the manifold (upper and lower), the relative pressure drops and the oil vapor condenses out and falls to the bottom of the intake manifold like rain. Gravity will take that liquid oil back down into the elbow in the bottom of the lower intake.

The thing I don't understand is where the liquid oil goes from there. There is no where for it to drain to...

 

[Quicktime_GT]

Awesome..

Here are some pics / drawings that might help someone out as well.

This is my KB and this routing is for a EGR delete / Bypass valve solenoid delete setup:

Here is one that helped me. ( thanks torqjunky)

He also supplied this one:

 

[mwolson]

Neil, thanks for the add. I am planning on dropping a KB on top of my Teksid Terminator build (currently on the back burner behind many projects.)

I am still curious as to what happens to the oil that condenses into the bottom of the lower intake manifold...

 

[exdeath]

I figured out that the "IPS" is the Intake Pressure Sensor" integral to the IAT2 sensor.

Yeah I realized that a while ago, it deceptively appears like it's branching off at the end of the PCV piping on the diagram, but really, it is it's own thing anywhere on the lower manifold and has nothing to do with PCV.

 

[mwolson]

Regarding where the oil goes from the oil separator, the consensus from the other forums is that, when you go into boost, the oil that has collected in the bottom of the lower intake is blown through the T back up into the upper intake and then most of it goes into the engine to be burned.

Pictures of badly oil fouled intercooler heat exchangers seem to support this idea.

Pretty messy way to handle oil vapors from the crankcase, I think. Anyone who doesn't run an oil separator is making a mess of his intake.