EGR and EFE for a 79

[Vette79]

I am planning to remove the hoses for the EGR and EFE components on my 79 prior to new intake install. Later this year I plan to install a Edlebrock Performer Intake Manifold without EGR and utilizing my existing rebuilt Qjet. I would like to know if removing the EGR and EFE hoses and/or hardware will present any issues now or later. What are the Pro's and Con's to this and is it a matter of removing the hoses and plugging off the open ports?

 

[bradfordsvettes]

I do not know if removing the egr is a good idea you could end up with preigntion issues .it really is not the power robber everyone thinks they are . if you remove the efe you could have cold running issues but that may not matter to you. juast be sure the valve on the exaust manifold is open or you could cause valve and hot running on the right side of the engine only my 2 cents steve

 

[bmotojoe]

I don’t see any problems removing the EGR & the EFE and plugging the vacuum thermo switch ports, located in the thermostat housing and the other located in the intake manifold.
Nor do I see a problem removing the vacuum hoses and capping the source ports on the carburetor. Sounds like your car still has the stock cast exhaust manifolds and if your planning on removing vacuum to the EFE actuator valve you may have to remove the heat riser valve as its normal position is closed because the actuator valve is vacuum to open and spring return to close. So no vacuum to EFE actuator the heat riser will be closed at all times. Removing the linkage rod from the EFE actuator to the heat riser valve may not insure that the heat riser valve will open under exhaust pressure.
Removing the heat riser valve will leave a gap between the y-pipe and right side exhaust manifold that will have to be closed up.
Brian

 

[Vettehead Mikey]

There's almost no benefit in removing or disabling these components, and very little benefit in swapping intake manifolds on this engine.

Are you sure it's worth the bother?

 

[Vette79]

Well, I no longer have the OEM stock exhaust manifolds. I have headers installed. I am under the impression that installing the Edlebrock Performer Intake manifold will provide some extra HP along with increased torque from idle up to 5500 rpm. I have to remove the OEM intake anyway. Thought about making some changes...

 

[Vette79]

There's almost no benefit in removing or disabling these components, and very little benefit in swapping intake manifolds on this engine.

Are you sure it's worth the bother?

No benefit in replacing the OEM stock intake manifold. How's that?

 

[bmotojoe]

Years ago I replaced my stock intake manifold with the Edlebrock performer. Drove the car that spring and summer and found no difference in performance on my stock L48. Went back to the stock OEM intake and its been that way ever since.
For me, it was exactly like Vettehead said, more then a bother then it was worth. The Edlebock has been hanging up on the pegboard as an ornament ever since.
The only benefit I found vs. OEM, if removing or installing the Edlebrock you can install or remove it one handed but what fun is that?
Brian

 

[Vette79]

Brian and Mikey, hey guy's thanks much for the info. If there really is no difference in performance then why waste my money purchasing a new one? I will remove the OEM L-48 intake and clean it up. I have to do this in order to tackle an issue with the stock choke so this is why I had created this post. Makes no sense to remove the EGR and EFE either. You guy's helped me make a pretty big decision. Stay original. Big project has turned into a smaller and less expensive one...

 

[bmotojoe]

If it were me doing this, and have the time when the car is down during repairs and you have a parts house that also has a machine shop have them soak the manifold in the hot tank to boil out everything overnight and then have them resurface it. They can dress it up making sure it is absolutely flat. I would say no more then $10.00 dollars for the cleanup and no more then $20.00 for resurface and it will be ready for paint that will stay around for a long time.
Brian

 

[Vettehead Mikey]

Brian's experience is pretty much the same as mine. The Edelbrock manifolds do work- if you're upgrading from a cast iron 2 barrel set up originally from an econo-box. The stock GM 4 barrel manifolds supplied on Corvettes are already top shelf stuff.

 

[Evolution1980]

vette79, if you want to have it looking purdy, you could consider sending it to Jet-Hot and have them do a nice coating on it. Normally, they do headers, but I think they will do other stuff you send to 'em. I'm not positive, but it might be worth checking into since you've saved some money by not buying the replacement manifold...

 

[Vette79]

The L-48 on a 79 is cast iron. Installing an aluminum intake by Edlebrock will help dissipate heat as well as provide more HP due to loss of weight right? 1lb of weight loss = 1 HP gain? Edlebrock claims in a response email to me that the Performer Intake will provide more torque and HP over stock. Maybe I really won't notice a difference unless I install new heads to get the full benefit?

 

[Evolution1980]

1lb of weight loss = 1 HP gain?

There is no direct correlation in that respect. If you the driver lose 10 lbs, did your car gain 10hp? No.

What you are looking for is the ratio of HP-to-weight. And at that, in my opinion, torque is more relative to weight since torque is what moves you, and it's about how much weight you need to move.

Simply changing your intake manifold may not make a noticeable seat-of-the-pants difference ("butt dyno" :gap). Changing the heads does stand to make a much greater difference.

 

[Vette79]

OK. Had second thoughts. Thanks for putting me back on track.

 

[Vette79]

OK. I removed the rest of the emissions on the Vette today. Drove for 20 miles at various speeds and on inclines. Outside temp was around 85 degrees. The water temp never went past 175 degrees. IMO the Vette seems to be a little bit more responsive. Of course it looks cleaner under the hood to. Eventually, my goal is to replace the cam and intake manifold to get just a bit more. I've kept everything that I have ever replaced in case we need to go back to stock at some point. Now, should I ever replace the air cleaner assembly and why?

 

[Evolution1980]

Now, should I ever replace the air cleaner assembly and why?

Over the years, I've questioned whether a open-element air filter is better than the single or dual snorkel setup. I would think that the snorkel setup with the OEM ductwork probably actually draws in cooler air than an open-element sitting atop a hot engine under a cramped hood. However, I decided that I liked the classic looks of the open-element versus the snorkel intake. I AM very curious to know if there actually is any performance difference.
My opinion was that, performance not being factored in, the snorkel setup just covered up too much of the beauty of nice looking engine bay. And I really just like the classic look of an open-element filter.

 

[Vette79]

Thanks EVO. I agree that the OEM setup is probably better due to it being a CAI. Think I will stick with it until it makes sense not to.