Madant26x

Can someone tell me the function of the part I have circled. I'm planning on redoing my vaccum lines and the updated diagram I have doesn't included this. Just wanted to know what the hell it is.

PorscheDoc

You have an 89 951, so it doesnt have the venturi tube crap, which that circled thing is a part of.

Madant26x

Nice, thanks Karl.

Another question, will I have to take my intake manifold off to remove the cycling valve? If so, can I reuse the intake manifold gaskets, or should I get new ones?

hosrom_951

Get new gaskets

PorscheDoc

Yea get new gaskets, you will rack up all of about an 8 dollar bill. The intake is pretty simple to remove, follow the instructions on clarks-garage.com and it will walk you through it. Plus then you can get a look at the lines under the intake to see if they need to be replaced.

ibkevin

Karl, Do the 87's have that?

PorscheDoc

Yea 87's have all that junk under there. Porsche got smart in either late 88 or for the 89 models and upgraded to using just 3 hoses. I have since updated my 86, and it is so much nicer not having that octopus of hoses under the intake.

PorscheDoc

all those parts circled are just t's errrrr y's i guess you would call them for connection the various vacuum hoses together.

Oddjob

You "can" get the cycling valve out and reinstalled w/o taking the manifold off, but it is a pain. Much easier to break the nipples off removing the hoses when the intake is still on. If you havent taken one off before, probably less swearing involved if you remove the intake. I would use new gaskets.

ibkevin

Doc, Where can I find additional info? I'm about to replace my 26/6 and while the intake is off it sounds like an EXCELENT plumbing project!!

TIA, Kevin

PorscheDoc

Well, here is the write up i did for the venturi delete. Keep in mind i ditched the cycling valve completely and plumbed a line from the wastegate to a manual boost controller to the intercooler pipe. The intake removal is spelled out pretty clearly over at www.clarks-garage.com in his shop manual.

Vacuum Line Writeup

It is about a meg Word file.

PorscheDoc

Oh kevin, while you have the turbo off, make sure you replace the 2 rubber o rings for the oil air seperator (oil fill tube). You pretty much have to remove the turbo to replace them if they ever leak (if they are not already), and they are all of about 6 bucks each, and an extra 10-15 minutes of work. Also check the rear balance shaft cover while the turbo and stuff are out of the way.

Darwantae951

Will my early 88 951S have the new or old system?

PorscheDoc

Not sure about the S, but we did Ben wornall's 88 951 and it had the venturi tube. You should be able to see one of the front silver metal pipes of the venturi tube if you look right behind the intercooler pipe at the front of the intake manifold.