Why can't you replace EGR?

I would be a fan of just turning off the EGR in the ECM software and relying on SCR only to take care of NOx. When you compare the cost of EGR, cooler, and associated problems when they grenade, I would be more than willing to pay for a little more DEF to tackle the problem. I contended all along that this is the way they should have went right out of the gate. EGR on a diesel is criminal and a sure sign that we are not advancing as a species in our ability to reason thru problems.

 

Pre SCR engines only used around 20% egr max. The 40-50% egr would be the Maxforce engines. Those engines use a lot of egr since they did not use scr to make epa compliance.

That being said there are operating conditions in which the engine will shut off the egr. Each manufacture has different requirements to achieve this end result. The result of it would be slightly less power when the egr is off so that you would want to get your engine fixed.

 

"I would be a fan of just turning off the EGR in the ECM software and relyingon SCR only to take care of NOx." According to the Cumming's document, you could do that, and then only times your would be out of emissions requirements would be during "cold start and warm up." both of these situations refer to cold oil at and during start up, but aren't there APU's out there you can use to heat the engine and engine oil? Then you'd be compliant even at cold start to meet emissions with the EGR deleted.
But I guess APUs cost money.

 

There are coolant heaters from Webasto and Espar that are diesel fueled just as their bunk heater counterparts are. They could heat the motor coolant and the DEF tank and everything would be as is the motor is warmed up already. I use a Wolverine oil pan heater religiously during cold weather, that could easily be used year round. All of these, at the very most, would only require keeping batteries up via a small portable generator run thru a inverter/charger. I do that now. The oil pan heater... about $150 and uses about 500w of AC power. Coolant heater would only use about the same DC power from the batteries as a bunk heater. Also, it can be set on a timer and can have the motor coolant at 150F in about an hour. Located a Webasto Thermo Top C coolant heater and kit on Ebay for about $1000. I am in the market here soon to put one on my Columbia with a Detroit 60 in it. I already have a Yamaha EF2000 portable generator in it's own frame rail box and the pan heater and a Xantrex inverter/charger that keeps the batteries up via the generator or shore power.

And all of this, except the portable generator, can be spec'd and installed at the factory when the truck is built at a much better cost than doing it after market. Factory installs always seem to work out better in the long run.

 

" That being said there are operating conditions in which the engine will shut off the egr."

I wish I had a technical understanding of when that happen. As far as I've been told, it happens in two circumstances: low engine load and from readings from the pressure gauge of the exhaust, but these seem to be contradictory. I would hope that you could at least use water injection to reduce EGT's, which would tell the EGR sensor that the Peak Combustion Temperature is lower, so it would re-circulate less exhaust gas back into the engine.

 

I would probably do it that way. Just wouldn't tell them that I'm using it to get rid of the EGR while remaining emission compliant @ start/warm up, they'd look at me like I had three heads lol.