Does the ultimate chip disable EGR operation?
- Thread starter mrweelr
- Start date
ParTyBoy
New member
Re: Does the ultimate chip disable EGR operation?
As far as I'm aware EGR is disabled through raising the intake temperature limit to initiate EGR on the chip to some ridiculous number that can never be reached... this way the EGR can never be enabled because the temperature can't reach the required number to initiate the function..
The t1-15 setting has either the same figure or close to as the stock number... Otherwise all other settings are disabled..
mrweelr said:
As far as I'm aware EGR is disabled through raising the intake temperature limit to initiate EGR on the chip to some ridiculous number that can never be reached... this way the EGR can never be enabled because the temperature can't reach the required number to initiate the function..
The t1-15 setting has either the same figure or close to as the stock number... Otherwise all other settings are disabled..
mrweelr
New member
Thanks, that's what I thought. Doesn't disabling the EGR increase combustion chamber temps, lean it out, and induce knock? It seems as if the benefit of slightly lower IA temps would be offset by the aforementioned drawbacks. I'm trying to weigh the pros and cons of having the EGR disabled and it seems like there's little, if anything, to be gained.
ParTyBoy
New member
mrweelr said:
NO... actually the opposite... recirculating those gases through the intake/combustion chamber actually increases temps... EGR is supposed to be better for our trucks, but in reality from the experiences of green and others Disabled EGR lowers intake temps & makes a truck perform/respond better... except for at or around driving at a continous Highway speed for an extended period from what I recall
EGR introduces inert gases into the combustion chamber, absorbing heat & energy, and usually decreasing the tendency for part throttle detonation. Fuel needs usually go up during EGR operation; in fact this is how the computer tests to see that the EGR system is in place and operating properly. It runs the EGR as a test, and then checks to see that the short term fueling term (integrator) increases in response to lean 02 readings.
Anyhoo, most trucks I have seen do not have part throttle detonation problems, and I've checked many of them that are run w/o an EGR. EGR introduces spent gases into the intake manifold & combustion chambers, increasing the amount of carbon deposits, leading to hot spots in the chamber, and possible detonation sources. Manifold air temps are very hot during EGR operation also, leading to more heat soak issues.
FWIW, the stock heads are setup so that the middle cylinders have an EGR port off the exhaust port, leading up to the intake, and from the intake up to the EGR valve, which opens the door to go into the intake plenum. Vortec heads do NOT have an EGR port off the exhaust manifolds. That port helps to create uneven flow & more heat in the stock (as well as L35) heads.
I've had several trucks pass sniffer tests w/o an EGR system.
Anyhoo, most trucks I have seen do not have part throttle detonation problems, and I've checked many of them that are run w/o an EGR. EGR introduces spent gases into the intake manifold & combustion chambers, increasing the amount of carbon deposits, leading to hot spots in the chamber, and possible detonation sources. Manifold air temps are very hot during EGR operation also, leading to more heat soak issues.
FWIW, the stock heads are setup so that the middle cylinders have an EGR port off the exhaust port, leading up to the intake, and from the intake up to the EGR valve, which opens the door to go into the intake plenum. Vortec heads do NOT have an EGR port off the exhaust manifolds. That port helps to create uneven flow & more heat in the stock (as well as L35) heads.
I've had several trucks pass sniffer tests w/o an EGR system.
Loeryder
New member
Anything in particular you did to pass and amissions sniffer without an EGR system?
I am in this boat right now.
Truck has no EGR or EVRV and running the Ult chip.
What setting is best for emissions when you have no EGR?
15PSI Street has EGR enabled right?
That will throw a code if teres no EGR, right?
Does Valet have EGR enabled?
I gotta pass the AWD dyno sniffer to get my plates.
You wouldn't by chance be able to burn me an "emissions Only" chip for a truck with no EGR?
I am in this boat right now.
Truck has no EGR or EVRV and running the Ult chip.
What setting is best for emissions when you have no EGR?
15PSI Street has EGR enabled right?
That will throw a code if teres no EGR, right?
Does Valet have EGR enabled?
I gotta pass the AWD dyno sniffer to get my plates.
You wouldn't by chance be able to burn me an "emissions Only" chip for a truck with no EGR?
TheObiJuan
Active member
god egr really sucks and so does emmissions. get rid of a few companys that burn coal and we call it even.
mrweelr
New member
Thanks for the detailed explanation Brian - you are a wealth of knowledge :wink: I do see part throttle detonation at times but it was happening even when the EGR was connected so I don't think that's it. More likely, it's the boost spikes I'm getting with the stock wastegate and ATR exhaust and cat. I just installed the SMC alky kit this weekend and will start testing this week. Will be interesting to see if it helps reduce KR using 91 octane. BTW, my IA temps dropped a good 20 degrees after disconnecting the EGR 