After reading some of the information on replacement vacuum lines I have decided to go with the Viton Rubber tubing from McMaster-Carr. The heat range -15 to 400 F sounded like it would do the job. Dose anybody know all the sizes that are needed for this replacement project.Also I thought I read that their is a reroute upgrade on the vacuum hoses for the 3rd gen. I just can't remember where I read it. Any info on this will be great.

 

http://www.scuderiaciriani.com/rx7/v...placement.html

http://www.rx7turboturbo.com/robrobinette/hoses.htm

As for the other part of your question, I believe you are referring to the "vacuum hose simplification". I believe the simplification removes some emissions functionality so if you are keeping your air pump and all the rest of that part of the emissions, just keep the hoses stock.

 

Look here for diagram of simplifcation. http://www.rx7turboturbo.com/robrobi...simplified.jpg

Very nice simples system, but as Mahjik said, you lose all of the emission related stuff, so if you need it, don't simplify them. Otherwise, it makes it a lot easier to diagnose a boost leak.

Why rubber and not silicon btw?

 

Thanks for the help you guy's are great. I called McMaster-Carr and oredered the hoses yesterday at 9:00am. When I came home to day at 3:30pm they were already here. Talk about service it dosen't get any bettter than that. If any one is leary about ordering from some place McMaster-Car is the place to go.

Just need the wire ties and in to the labortory I will go.

Brian

 

Just curious, how much did you pay for all that Viton?

 

Cirian's site shows a second set of diagrams showing an "empty pipe". Is that the nipple I'm seeing underneath my UIM that has no hose attached? That "empty pipe" is not shown in the other two diagrams on Ciran's site?

 

Well, without seeing the nipple you are talking about it's hard to say. But there is a nipple down there that is for AT's only. So on manuals, it will be left open.

 

Here's Cirian's site http://www.scuderiaciriani.com/rx7/v...placement.html Scroll down to the second diagram. The nipple with no hose is labeled "empty pipe". This must be the one all MT FDs have that has no hose attached, right?

 

I have a full set of VITON from McMaster-Carr that I purchased but then decided not to use. The wall thickness was just too thin to resist kinking in some of the locations under the manifold. the tubing looks great as far as the resistance to oil and fule but the walls are just not thick enough to be comfortable with considering the amount of time and effort to install it and the resulting PITA it would be to troubleshoot the turbo controls if it were kinking and restricting. I went with quality thick walled silicone and am hoping for the best. After talking with people who had been running silicone for a few years on their cars nobody had issues with gas/oil problems but more with cuts and nicks during installation or maintance around the hose. if anybody wants the Viton hose set I'm open to trades or purchase. I will have to see what I paid for it.

 

The viton tubing you ordered was likely the wrong kind. Under the McMasters viton page, you will see both english and metric sized tubing. Under the english units, there are two wall thickness options. You have to go with the thicker of these two for an FD application. The sidewall for the metric-sized tubing is 1/2 of the thickness for the fatter english unit tubing and is inadequate, as you discovered.