2G What's the point of blocking off EGR valve (Merged)

[roketmarc90]

whats the point in blocking off the EGR valve?
im kinda new on turbo cars

 

[90gsx_turbo]

Yea i just got my 90 gsx awd turbo and my egr valve is blocked off too and im wondering if that was pointless or was he a moron and i'm having a problem with my boost controller too

 

[roketmarc90]

Yea i just got my 90 gsx awd turbo and my egr valve is blocked off too and im wondering if that was pointless or was he a moron and i'm having a problem with my boost controller too

well i see alot of ppl block it off and i was just really scratching my head wondering why

 

[pgarland]

The EGR valve recirculates hot, dirty air back into your motor as a way of cutting down on emissions. The problem is, it dumps all that carbon back into the motor as well. Blocking off the EGR will keep your intake much cleaner, which is really the only true benefit you gain from blocking it off. If you've ever seen what a dirty EGR does to your intake, or how much crap comes pouring out when you spray a can of carb cleaner into one, it's pretty easy to see why blocking the EGR seems like a good idea.

There is an argument out there that since the EGR recirculates hot air into the motor, blocking it will cause the motor to only use cool, fresh air, and that is supposed to give a small boost in hp and efficiency. From everything I have seen though, if there are any actual power gains from blocking the EGR, they are too small to even notice.

 

[TALONTRAX]

The main pourpose of the egr.system is to reduce oxides of nitrogen emissons (nox) during accelleration. This is done by allowing a small amount of exhaust gas to be re-circulated into the intake only during accelleration (egr = exhaust gas recirculation). A second benefit of the egr system is that exhaust gasses are inert (all energy has been spent from it) & the introduction of a small amount of it into the combustion chamber not only reduces nox by replacing some of the combustible air with inert exhaust gasses, this process also reduces detonation (knock). I have my egr system intact & never had a carbon buildup issue . . .

 

[DSMunknown]

I'm just happy my intake manifold was 90-something-percent cleaner after I installed the block-off plate. I'm sure VE would also be improved, not to mention mass airflow.

 

[90gsx_turbo]

Well could that be the problem why my car idles bad

 

[XiKeiyaZI]

Bad EGRs have been known to cause Idle issues.

 

[90gsx_turbo]

ok thank you ### my car idles bad and two i'm having trouble figureing out my boost controller too ### i traded my old car for this one and the guy had it hooked up but when i turned it down my car read 10 11 psi and same when i turned it all the way up

 

[gusu]

There are SEVERAL issues with why 1g DSMs idle surge.

A failed EGR can cause it.

A stuck ISC can cause it also. Also note a stuck ISC can actually cause your ECU to have problems also. Make sure to check that!

Leaking caps on your ECU can cause idle surging.

Most common reason for your car to idle surge however is that the throttle body needs to be cleaned.

I'd suggest to check them all regardless of how pointless you think it would be.

 

[millermanx69]

i did the egr valve mod and now my car idles fine, and well of course readjusting my biss screw...turned it in all the way til it couldnt go in no more then backed it out about 2 full turns and now she idles at 750

i tried fixing the idle b4 i did the mod with adjusting the biss screw in all the way then 2 turns out and still idled funny...did the mod, problem solved

 

[arowell9]

my car would continously stall out, it was the problem that my egr valve was opening when i was in boost but never closed i got the egr blockoff plate a 15 dollar part and the problem was solved.

 

[9!'clipseDOHC]

Quote from the VFAQ:

What is EGR?
EGR stands for Exhaust Gas Recirculation, and its' purpose is to reintroduce the unburned fuel in your exhaust back into the combustion chambers. This is done when you come off the throttle and the exhaust is full of unburned fuel. Under acceleration the valve is closed, when lifting throttle the valve is opened. This keeps the exhaust cleaner.
Why block it off?
The idea is that if you block this off the hot exhaust gas will not mix with cool fresh intake air and will keep the intake manifold and charge air cooler.
How can I do that?
It is blocked off below the throttle body. I removed the battery, intake hose, and throttle body elbow to get more room. Remove the EGR gasket and cut out a piece of solid metal in the shape of the gasket. Reassemble using the solid material. This will block off the EGR flow.
What HP do I get by doing this?
Possibly none at all, except for a little from the cooler intake air.

 

[LiquidX]

Another reason to block off the EGR is due to most aftermarket intakes no longer have provisions so it's required. Next is to help with the deposits left in the intake.

Say you pull off your intake and look into it, you will see nasty stuff on the inside. Naturally you will clean that out and see better air flow (less turbulence) but having your EGR working normally will eventually cause that gunk to form up again.

Vacuum/boost leaks are another cause for them to be blocked which was stated earlier as well.


Truthfully unless there is a need or you no longer have emissions, there isn't a real reason to block it off.

 

[Ninja GSX]

The EGR valve recirculates hot, dirty air back into your motor as a way of cutting down on emissions. The problem is, it dumps all that carbon back into the motor as well. Blocking off the EGR will keep your intake much cleaner, which is really the only true benefit you gain from blocking it off. If you've ever seen what a dirty EGR does to your intake, or how much crap comes pouring out when you spray a can of carb cleaner into one, it's pretty easy to see why blocking the EGR seems like a good idea.

There is an argument out there that since the EGR recirculates hot air into the motor, blocking it will cause the motor to only use cool, fresh air, and that is supposed to give a small boost in hp and efficiency. From everything I have seen though, if there are any actual power gains from blocking the EGR, they are too small to even notice.

Actually it is not hot dirty air. The EGR recirculates a small amount of exhaust gas which is very different. That exhaust gas is what is known as inert, meaning it can't react or burn. EGR does more than improve emissions, it also improves performance.

But ignorant people have it in mind that anything related to emissions is bad for performance so deleting it will improve performance. I've seen a professional racer render a car doing this.

 

[9!'clipseDOHC]

Actually it is not hot dirty air. The EGR recirculates a small amount of exhaust gas which is very different. That exhaust gas is what is known as inert, meaning it can't react or burn. EGR does more than improve emissions, it also improves performance.

But ignorant people have it in mind that anything related to emissions is bad for performance so deleting it will improve performance. I've seen a professional racer render a car doing this.

How do "inert" exhaust gases, which can't burn, help anything in the combustion (Noun. The process of burning.) chamber?

EGR is typically not employed at high loads because it would reduce peak power output. This is because it reduces the intake charge density. EGR is also omitted at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle. - taken from wikipedia.com

 

[Ninja GSX]

How do "inert" exhaust gases, which can't burn, help anything in the combustion (Noun. The process of burning.) chamber?

Because they are inert and don't burn, they slow the burn rate of the air fuel mixture. Which is the same thing that octane additives do. The key to performance is fuel burning rapidly so there is a controlled expansion, versus detonating. When the air fuel mixture detonates it is an instantaneous explosion which occurs so fast that the piston can't move with it and harness the energy.

So EGR reduces detonation. When detonation occurs the knock sensor sends a signal to the ECU and the ECU retards timing to compensate.

 

[so slow 420]

What the purpose of people blocking off the egr valve

 

[inthemidst]

It's circulating hot air into the cylinders which causes knock and blows your engine

 

[so slow 420]

So I should block it off my old talon was blocked off when I got bought car now my eclipse I have now is still intack and knock r u preferring to crankwalk

 

[JackStieben]

Most people block off the egr, but you can't only do that. You have to delete all of the emissions in the car to remove it correctly.

 

[so slow 420]

Emissions is that the black box up under the steering wheel with like 10 wires going to it I'm new to this so help is apreciated I'd like to do everything to avoid the crankwalk

 

[inthemidst]

No crank walk is something else knock is when the the engine ignites itself from high heat instead of waiting for spark the way it's suppose to work

 

[inthemidst]

Honestly I don't know why this guys saying u have to remove all emissions maybe he can explain that.

 

[so slow 420]

OK so in ur opinion would u block off egr and steps on how to go forward to do so thanks