Calan
DSM Wiseman
- 7,250
- 399
- Jan 16, 2007
-
OKC,
Oklahoma
Once I figured out what I wanted to do with the catch cans, everything else around the intake manifold started falling into place.
First up was modification of the PCV valve outlet on the VC. I've never liked the way it comes straight out and into the TPS, so I decided to modify it for a better angle towards the catch can. I also wanted to keep the snorkel to help eliminate as much oil from getting in the lines as possible, and after playing around a while I came up with something I like. A tech article that contains the steps involved can be found here.
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In the pics below you can see how the PCV valve is routed to the inlet on the catch can. The outlet of the can goes through a check valve and is routed back through the middle of the manifold, into the original PCV port which has been retapped for 1/8" NPT. With the fuel rail in place, the PCV return line is barely visible.
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Once the PCV was taken care of, it was time to turn my attention to the vacuum routing on the IM. Like the PCV valve, I think the location of the factory IM vac routing leaves a lot to be desired....so I changed it.
After a couple weeks of searching, I gave up on finding any off-the-shelf plugs that would fit the two small ports at the front of the IM. I believe they are BSPT threads, but I'm not sure on the size and I never found a source for BSPT fittings, even if I did know the size.
But what I do have a source for are the factory nipples. So I bought a couple of those for about $4 a piece from Mitsu, and cut/welded them to make my own plugs... problem solved. In the second pic below, you can see them underneath the PCV hose. Once they are painted black they'll blend in completely and dissappear.
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With the factory holes plugged, I needed new vac sources. I wanted them to come from the back of the IM and to not be noticable, so I fabricated a vacuum manifold that bolts to the IM next to the throttle cable bracket. It's made from 1/2" thick aluminum bar stock with a piece of 1" x 1/8" aluminum welded to it. 1/8" NPT nickel-plated barbs and a -4AN fitting from Summit Racing finish it out.
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The vac source for the new manifold comes from the original brake booster port (which was retapped for 1/8" NPT), and the manifold has outlets for the boost sensors and BOV. (The -4AN fitting is for the BOV line).
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For the brake booster, I drilled and tapped a new port next to the old one. Mitsu convienently added a boss to the IM in just the right place for this, so it was really simple. In the second pic below, you can see the line going from the original port on the right over to the vacuum manifold mentioned above (before it was painted.)
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I also made a new booster hose, by hacking the original booster line and using a check valve from US Plasics. It has almost exactly the same flow and crack pressure as the stock hose, so I think it will work nicely.
Note: Although I'm fairly confident that the new booster line will be safe and work properly, I am going to pressure test it and beat on it just to make sure. Worst case, I can use a stock one although it won't fit as well.
View attachment 1000
In the next part I'll get into the catch can lines, suspension, and other projects.
Stay tuned!
First up was modification of the PCV valve outlet on the VC. I've never liked the way it comes straight out and into the TPS, so I decided to modify it for a better angle towards the catch can. I also wanted to keep the snorkel to help eliminate as much oil from getting in the lines as possible, and after playing around a while I came up with something I like. A tech article that contains the steps involved can be found here.
View attachment 1016 View attachment 1007
View attachment 1017
In the pics below you can see how the PCV valve is routed to the inlet on the catch can. The outlet of the can goes through a check valve and is routed back through the middle of the manifold, into the original PCV port which has been retapped for 1/8" NPT. With the fuel rail in place, the PCV return line is barely visible.
View attachment 1003 View attachment 1008
Once the PCV was taken care of, it was time to turn my attention to the vacuum routing on the IM. Like the PCV valve, I think the location of the factory IM vac routing leaves a lot to be desired....so I changed it.
After a couple weeks of searching, I gave up on finding any off-the-shelf plugs that would fit the two small ports at the front of the IM. I believe they are BSPT threads, but I'm not sure on the size and I never found a source for BSPT fittings, even if I did know the size.
But what I do have a source for are the factory nipples. So I bought a couple of those for about $4 a piece from Mitsu, and cut/welded them to make my own plugs... problem solved. In the second pic below, you can see them underneath the PCV hose. Once they are painted black they'll blend in completely and dissappear.
View attachment 1001 View attachment 1002
With the factory holes plugged, I needed new vac sources. I wanted them to come from the back of the IM and to not be noticable, so I fabricated a vacuum manifold that bolts to the IM next to the throttle cable bracket. It's made from 1/2" thick aluminum bar stock with a piece of 1" x 1/8" aluminum welded to it. 1/8" NPT nickel-plated barbs and a -4AN fitting from Summit Racing finish it out.
View attachment 1009 View attachment 1010
The vac source for the new manifold comes from the original brake booster port (which was retapped for 1/8" NPT), and the manifold has outlets for the boost sensors and BOV. (The -4AN fitting is for the BOV line).
View attachment 1011 View attachment 1015
For the brake booster, I drilled and tapped a new port next to the old one. Mitsu convienently added a boss to the IM in just the right place for this, so it was really simple. In the second pic below, you can see the line going from the original port on the right over to the vacuum manifold mentioned above (before it was painted.)
View attachment 1004 View attachment 1005
I also made a new booster hose, by hacking the original booster line and using a check valve from US Plasics. It has almost exactly the same flow and crack pressure as the stock hose, so I think it will work nicely.
Note: Although I'm fairly confident that the new booster line will be safe and work properly, I am going to pressure test it and beat on it just to make sure. Worst case, I can use a stock one although it won't fit as well.
View attachment 1000
In the next part I'll get into the catch can lines, suspension, and other projects.
Stay tuned!
