Hammer Down

I understand the purpose of the egr valve. But what benefits do you see taking it off?


thanks

black6gen

Depends on your setup.

MaxPower

Clean up the engine bay. The benefits out way the cleanliness I think.

I'v never heard of an EGR block off helping unless you get a different intake manifold that cant support one. Can you give more info on certain setups?
or just an example. You got me curious now

BAD4DR

The EGR recirculates exhaust gas into the intake to do 2 things:

1) Heat the air for better emissions
2) Burn off some of the excess waste gas by combustion

By blocking off the EGR, you may see lower intake air temperatures. This may hurt mileage, and emissions, but may improve horsepower. Depending on the design of the motor, and the specific output, this could be 1-2 hp (barely noticeable) or 15-20 hp.

Blocking off the EGR may also hurt "driveability" in that it may run leaner at times than normal, it may do some other things it technically shouldn't on cold starts, and/or on colder days. So although it can provide some power, if everything is right, and you're really needing it, it can also have some downfalls.

High horsepower, highly stressed applications, and older less efficient designs usually see the most benifit from blocking off the EGR, but there are exceptions.

What it would do on your specific application???? Ask someone with that application, that has done so.

MaxPower

The main reason for making an EGR is to allow an inert gas to go into your combustion chamber. By taking up space when mixing with your a/f it lowers combustion temps and saves gas by giving a cooler burn and more controlled flame front with less fuel used. It is only used on half throttle applications, Not WOT. I dont see how it would take away any useful HP. By taking it off or blocking it there will be no lean mixture since your car will compensate to remain stoichiometric. I have yet to see plausible results on a car gaining HP on a dyno but I have seen a lot of Nox reduction from the lower combustion temps.

Also I dont even think the EGR is used until your are in closed loop.

BAD4DR

EGR is a system. Not all of them have valves. Many of the older V8 style systems are continuous. Some manufacturers use a closed-loop only setup. Want a good example of a WOT open setup? 1st gen Dodge Neon. Pretty good horsepower gains reported from EGR block-off.

I understand it reduces emissions outputs. But it does so by pre-heating the combustion charge. This makes for less dense air, less oxygen in the air, and less fuel needed to create a complete burn. It effectively leans out the system, and allows it to function well. By removing this charge, it's entirely possible it will set a code, but aside from that, it will cause there to be an additional amount of oxygen, and therby the car can run lean.

MaxPower

Your talking about a Heat control valve integrated with an EGR. Most EFI engines do not use these. Thats real old school from what I'v seen. Mostly designed for carbureted and throttle body injection systems.

MaxPower

I have never touched a Neon before but I call bullshit on this. EGR's are not open at WOT.

BAD4DR

Then why does Mopar Performance offer an EGR Block-off for HP gains (not street-legal, of course) If it doesn't make a difference at WOT, it won't be showing gains on a dyno, would it?

BAD4DR

Most all of them I've seen have used carbs. But it still exists, and in major quantity. The system depends completely on the vehicle, and manufacturer design. Some vehicles basically won't show gains. Others, will pick up some pretty good #'s.....