EGR passage question.
Thread Starter
Race Director
Joined: Jun 2004
Posts: 13,963
Likes: 709
From: WI
EGR passage question.
I have EGR block off plates on the intake in the back where the pipe comes on, and on the EGR valve. I notice on the intake manifold one side has a small square passage by the square air openings into the head, and one side does not. Can this be blocked off, and any ideas how? I notice that air can go through that passage, up to by the EGR valve and into the small round pipe on the runners, into the plenum.
Race Director
Joined: Aug 2000
Posts: 14,130
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Cruise-In II Veteran
Ignore it.Its not going to do anything.Unless you have a working egr that draws vaccum its not going to affect anything.
That opening in the had area looks to be more of a heat riser passage,than egr.
That opening in the had area looks to be more of a heat riser passage,than egr.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Not to hijack, but I have a question.
Ive seen a few members here that lately have disconnected/tuned their EGR off. The biggest complaint they have is knocking when initially giving it gas regardless of rpm. The purpose of the EGR is to draw hot gases out of the combustion chamber (and reburn) reducing this risk, right? So if the gases have nowhere to go and they get that knocking, whats the advantage?
Ive seen a few members here that lately have disconnected/tuned their EGR off. The biggest complaint they have is knocking when initially giving it gas regardless of rpm. The purpose of the EGR is to draw hot gases out of the combustion chamber (and reburn) reducing this risk, right? So if the gases have nowhere to go and they get that knocking, whats the advantage?
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Pre '88 intakes had the IAC air going directly to the ports whereas later models vents IAC air in behind the TB.
All manifolds (same casting #) have the holes whether they were used or not.
On later "non cold start" versions the runner flange is cast to cover the hole at the manifold and the IAC air tube is missing,ie one small tube for EGR instead of one per side on earlier.
"they have is knocking when initially giving it gas "
I beleive the ECM only operates the EGR in cruise condition ,I can not see any connection between EGR delete and knocking.
Have had mine removed for 5 years , made no difference to accel
All manifolds (same casting #) have the holes whether they were used or not.
On later "non cold start" versions the runner flange is cast to cover the hole at the manifold and the IAC air tube is missing,ie one small tube for EGR instead of one per side on earlier.
"they have is knocking when initially giving it gas "
I beleive the ECM only operates the EGR in cruise condition ,I can not see any connection between EGR delete and knocking.
Have had mine removed for 5 years , made no difference to accel
Thread Starter
Race Director
Joined: Jun 2004
Posts: 13,963
Likes: 709
From: WI
Alright, thanks! I got a used intake and it's all black sooted up. They had an EGR block off on the small tube in back that is from the exhaust tube, and the EGR valve was still on. I don't know if it was working or not. The whole intake is badly sooted though. I'd like for that to not happen again, that's why I was wondering if carbon gas was flowing by the IAC into the TB.
