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Discussion Starter #1
Is it working on the principle of just blocking the exhaust gas flow? Or does it build really high boost levels combined with no fuel? Or both, or some other way?

Does the VGT nozzle move in the same direction under EB use as it does during normal operation and does it extend farther during EB or the same as regular. If it actually moves to a position beyond what it travels during normal boost (which is sure what it feels and sounds like while driving) then EB use would be pretty important to mitigate the soot fouling. Not that it's helped me any. I run my EB all the time and still have the 2262 code.
 

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The 'textbook' answer for you...

VGT EXHAUST BRAKE
The VGT Exhaust Brake works in conjunction with the engine and transmission to provide an integrated braking system to help slow the vehicle. This is commonly referred to as exhaust braking. Braking power is achieved by modulating the sliding nozzle ring to restrict the flow of exhaust gasses from the engine, this will create high back pressure on the engine. The high back pressure creates a high level of resistance to the motion of the pistons within the engine and this resistance is used to reduce engine speed and thus vehicle.

The exhaust brake feature will only function when the Exhaust Brake Switch to the ON position. With the switch in the ON Position and the vehicle moving faster then 5 MPH; the exhaust brake will automatically operate when pressure is removed from the accelerator pedal allowing the ECM to see 0% throttle and 0% fuel delivery.
 

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Is it working on the principle of just blocking the exhaust gas flow? Or does it build really high boost levels combined with no fuel? Or both, or some other way?

Does the VGT nozzle move in the same direction under EB use as it does during normal operation and does it extend farther during EB or the same as regular. If it actually moves to a position beyond what it travels during normal boost (which is sure what it feels and sounds like while driving) then EB use would be pretty important to mitigate the soot fouling. Not that it's helped me any. I run my EB all the time and still have the 2262 code.
With trhottle at 0 and fuel at 0 the and engine brake on it will go to full boost postion which is 46 psi max this restricts air flow though the engine thus slowing the engine. :thumbsup

If the nozzle cant move you get a P2262 code.

Also do you have an after market drop in air filter?
 

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Discussion Starter #4
I'm bone stock. The dealer is scheduled to replace the turbo on Thursday. So, EB=full boost postion (up to 46psi). It's sort of funny that I can't actually tell that anything is wrong based on the way the truck drives, but I'm getting the 2262 all the time. It goes back on almost immediately after the dealer clears it.
 

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dang where is this 46 psi when I stomp on it???
 

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What is the VGT nozzle? Excuse my ignorance.
 

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What is the VGT nozzle? Excuse my ignorance.
It is what moves inside the turbo to make or decrease boost on the VGT turbo. Also is servo motor controled by the ECM.

This turbo does not have a waste gate or 2 fixed wheels like a normal turbo.
 

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Discussion Starter #9
Interesting stuff. I downloaded one of the online magazines and one of the stories talked about sizing and selecting the proper turbo. There was a comment in the story about how back pressure in the exhaust system affects turbo performance, especially DPF's. It says the back pressure changes as the DPF accumulates more soot and then lowers after a regeneration. I wonder if this is the source of some of the variability we notice in the truck performance. The article says VGT turbos can adjust somewhat to accomodate changing back pressure. I guess they can't adjust once they reach maximum travel, and I think we would see that most often during exhaust brake operation. I've noticed that the EB does seem to change power - some days it's really strong, other times mild. Maybe the DPF has something to do with it.
 

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Interesting stuff. I downloaded one of the online magazines and one of the stories talked about sizing and selecting the proper turbo. There was a comment in the story about how back pressure in the exhaust system affects turbo performance, especially DPF's. It says the back pressure changes as the DPF accumulates more soot and then lowers after a regeneration. I wonder if this is the source of some of the variability we notice in the truck performance. The article says VGT turbos can adjust somewhat to accomodate changing back pressure. I guess they can't adjust once they reach maximum travel, and I think we would see that most often during exhaust brake operation. I've noticed that the EB does seem to change power - some days it's really strong, other times mild. Maybe the DPF has something to do with it.[/QUOTE

Good possibility :thumbsup
 

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With trhottle at 0 and fuel at 0 the and engine brake on it will go to full boost postion which is 46 psi max this restricts air flow though the engine thus slowing the engine. :thumbsup

If the nozzle cant move you get a P2262 code.

Also do you have an after market drop in air filter?

Durring full exhaust braking Im only showing at MOST 10 pounds of boost.
 

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Durring full exhaust braking Im only showing at MOST 10 pounds of boost.

Your Edge may show 10, but your turbo is capble of 46psi if your ECM calls for it.:thumbsup
 

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Your Edge may show 10, but your turbo is capble of 46psi if your ECM calls for it.:thumbsup
Who said I have and edge? thats with a gauge.
 

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I would think that the amount of boost would depend on the load on the vehicle, you know like how much effort it takes the turbo to actually slow the motor down!
 
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