I am about to start porting my Crossfire Injection manifold. My question concerns the huge EGR passage in the manifold. The standard practice is to disable the EGR and chop this passage out of the manifold. I want to keep my EGR. Before you flame me for this I'll let you know that this EGR battle has come up before and I side with JPrevost and the others who think it doesn't hurt performance. So back to my question, I want cut the passage out of my manifold for flow, but then run I small hardline in its place to keep the EGR working. In pics with the passage removed I think I see a small hole where the exhaust would flow in, I want to tap this hole and run like a piece a brake or fuel line to the center of the plenum. I think this should work ( don't vortecs use external EGR with hardlines to the exhaust manifold ? ). Oh, if someone has close up pics of a Crossfire manifold with the EGR passage removed please post them. Thanks

 

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I have a pic of a manifold, look on http://www.crossfire.webhop.net/twinnie

There is a pic somewhere. I'll try to add it here but chances are the url is incorrect
(it doesn't turn up now when I'm typing this, server is offline again)

In that pic BOTH holes are opened, both the passage coming from the EGR valve (right one) and the feed coming from the head (left one), don't open up the left one.

Your idea would work but you'd have to make sure the mouth of your pipe is in the center of the manifold.

If I would do it I'd remove the EGR completely (all the volume taken by the EGR gasses can't be occupied by air/fuel -> performance loss!)

Marck

 

If anyone thinks that introducing an incombustible gas into the combustion chamber (along with fuel and air) does not hurt total performance, they are fooling themselves.

EGR helps with emissions and can raise mileage, if done correctly. also, if inactivated at higher rpms and/or higher engine load, no harm done to performance. Keep it if you like. Just be sure to tune around/with it.

 

Wow that pic is a mess! I have never seen that hole on the left side! But all of the pics I have seen show a small round hole left after the passage is cut away, is this pic just cut back more? My EGR tube will follow the shape of the original passage, just much smaller. It was a PITA to find this manifold so I am trying to find out as much info as I can so I don't screw up.

 

The hole on the left is the exhaust passage to the egr. This passage should not have been exposed. The right hole is the egr to the intake passage. The one you will need to deal with.

If you haven't been there. The Crossfire Forum has a lot of good info on intake porting as well as other stuff. http://www.crossfire.webhop.net/cfforum

 

If this car is for highway use then legally you have to keep it.

But, I would wonder how much removing the tunnel would effect the EGR distribution.

If you sit down and look at it yu'll see the reasons for removing the tunnel. Hint: measure the plenum volume. You could of course built up the sides of the lid to raise it say 1/4" and that would help.

BTW, 4 years ago ran mid 13s with a 350 cross fire.
But, did alot of tinkering to do that

 

I finally decided to chop out the passage and leave the EGR on but block it off. That way the computer will think it still has EGR. Here in Texas they don't test for NOx emissions and even if they start I'll just build another plate that lets exhaust gas in for the sniffer test, might mess up the exhaust gas distribution but oh well.