ok, what would I need to do to remove the EGR setup ??, I have 87-up heads... and a TBI, I'm going to buy a new intake manifold SO, i'm open to suggestions... If I remove the EGR, will it effect the TBI, or computer, ????? would I JUST need to purchase a NON EGR manifold, or what ???? what is it needed for my idea?
thanks guys... by the way.. I pay for a sticker (so I don't need to pass emisions)
:hail: :hail: :hail:

 

you need a new chip with the egr removed.

 

Here's something I found about the EGR. It is not a bad thing. It does good stuff.

The only time the EGR doesn't work is at WOT, which is when you don't want it to work anyway. ANY OTHER TIME you want it working.

 

You won't gain any performance from removing it. You will however prevent the engine from being coated with carbon buildup.

 

Care to explain that??

That's right up there with "leaving a battery on a concrete floor causes it to drain faster", isn't it?

 

OK, go take your intake manifold off and look inside. It will be covered will soot. You won't find that in an engine without egr.

 

Not true. I've had many carbed intakes without EGR that had soot in them. It's mainly caused from intake charge reversion.

As you know, every cam has overlap. If the cam is running below it's peak torque, and the throttle is barely open (like ~1700 RPM on the highway like my car), then the overlap in the cam can cause the intake charge to be pushed back up into the intake manifold, as well as some exhaust fumes.

It's caused from the negative pressure differential in the plenum of the intake being lower than any one cylinder's pressure differential at certain valve timing, mainly right as the intake valve is opening. You can see this if you look at the cam card of any cam. The intake valve opens Before Top Dead Center (BTDC)**.

As you'll see, the piston is actually still on it's way UP when the intake valve begins to open. It will push exhaust back into the fresh air/fuel charge in the intake manifold before the piston starts its downward travel. This is what causes the soot; the unburt fuel.

Ever notice how the tail pipe(s) builds up soot around it? That's from running too rich, whether it be at start-up or wide open throttle. THAT is what causes soot, not the EGR valve.

The neat thing is the LS1 engines (or possibly the LT1) do NOT use EGR valves because the intake reversion and valve overlap is high enough at cruise RPMs to do what the EGR valve does. I'm not 100% sure which engine it is though. It may be both.


** As usual... there are some acceptions to this. Some cams don't open the intake valve until After Top Dead Center. This is rather rare though.

 

Actually my 2000 LS1 does have EGR and I just recently removed the stock LS1 manifold to find soot coated inside the manifold. This is definitely caused by the egr because the design of the LS1 manifold doesnt allow for carbon to form from overlap like on carb manifolds. I understand what causes carbon buildup in the exhaust, but this is completely different from the intake manifold. If you look closely, I bet you will find more buildup around the valve than any other part of the intake manifold. This is obviously caused from the exhaust gasses being reintroducted into the combustion process via the egr valve and coating the inside of the manifold similar to the same effect it has on the exhaust pipes.

 

OK, now a difficult question...
I have a TBI 305... (in progress) .. It has MAJOR HEAD WORK, an LT1 cam, TBI mods/injectors/pressure reg... I haven't purchased the intake manifold yet... I can either get the edelbrock which is designed for TBI/EGR, the holley that is ALSO designed for TBI/EGR, or buy a manifold that has EGR, and then also purchase an adaptor plate for carb to TBI... any suggestions ??.. I need something LOW-RISE (because I wanna use a TBI spacer, and don't want to get a new hood), and with EGR, that's all... preferably someting that will increase power/torque... something with GOOD flow..
HERE'S THE DIFFICULT QUESTION, with the mods I have on my car,, do I need to use the stock EGR valve for an '89 TBI-305... or one from a bigger engine (a TBI 350) or what ??? :hail: thanks

 

The Holley adaptor is tall enough to be a spacer (****in huge). You can run a decent sized intake in your car and not worry, although anything higher than a performer RPM and Holley adaptor and you'll be in some ****.

 

OK..... then it must be the LT1.

Anyway..... you're trying to say that removing the EGR valve will keep the intake manifold from getting coated with soot.
THAT'S WRONG!!!!

I never said the EGR valve didn't cause soot... It does; for the same reason that intake reversion does. That's what I was trying to explain. Learn to read.

What I'm trying to do is make sure that YOU don't mislead people into thinking that removing the EGR valve will stop all soot from building up in the intake manifold.
IT WON'T!!!

Need I say more???

 

HEY HEY HEY, no need to argue.

is it??? I was told by the guy at holley that is was only 3/8 of an inch tall... , plus Couldn't I use a carb spacer, since I will probably use a carb manifold ???... IN ADDITION to the adaptor... this way I would get the whole inch of spacing...

 

Damn, a little pissy are we? Jeez man I didnt mean to make you mad or anything. No, removing the egr will not eliminate all soot from forming, but it will keep it from forming as much. To me, anything you can do to remove contaminants being put into my engine is worth it to me. I say if you will pass inspection without it then just get rid of it and get a custom chip and you will never have to worry about it again. Understand what I am saying now, I mean damn some people can get all pissed off over nothingl By the way, LT1's do have egr. The 2001 and up LS1's and the LS6 do not.

 

random quesion since were talking about egr, my car backfires on de-celleration --like a gun shot-- ive checked the entire ignition system and gapped the plugs at .45 , advanced the timing from 0 to 12 in two degree advances, ...all advances caused a backfire still....could the egr somehow cause this? everything on my exhaust is tight as it can be.....so is the intake...backfire happens one single time after i hit WOT for 10-20 moh, 2-4k rpm

 

The adaptor Im using is taller than 3/8ths, Id say closer to a full inch. I think its the 17-45 but Im not sure.

Picture