after market exhaust brake

[kckokesh]

I have an 08 3500 C&C with 6 speed manual transmission that came with the factory exhaust brake. In comparison to the Jacobs exhaust brake I had on my 2001 24 valve there is no comparison. The hold back on the factory exhaust brake is half as good as the Jacobs. Is anyone else dissappointed with the factory exhaust brake? Has anyone replaced the factory with an after market model such as Jacobs?

 

[HBarlow]

Uhhh, your truck doesn't actually have an exhaust brake. The ISB6. 7 engines use a variable geometry turbocharger that closes the vanes to block exhaust output and create exhaust braking.

I suppose you could turn off the exhaust brake functioni but nobody makes an aftermarket exhaust brake for an engine that has one designed as a part of its turbo.

If your previous truck had better exhaust braking than your current one it is only because of transmission and differential gearing. If you gear down you'll have exceptional exhaust braking.

Both the old Jacobs which I once owned in an '01 HO six speed and an '06 48RE could block the exhaust discharge, so does your VGT. The only difference is the method for doing the same thing.

 

[kckokesh]

Sorry for taking so long to reply but thanks HBarlow for the technical clarification. My fault for being simplistic in my description of the variable geometry turbocharger that is being used as an exhaust brake on the 6. 7. I should mention that I live and work in Colorado and have a Class A CDL so I do have some idea how to use an exhaust brake and other types of engine retarders correctly but thanks for the driving lesson.

Please let me rephrase my question. Has Dodge/Cummins made any design changes in 09, 10 or 11 to the turbocharger so it will perform better as an exhaust brake? Or is there an aftermarket system that could be installed on my 08 6. 7? Another problem I've recently experienced is that the exhaust brake will activate even when the switch is not on. Generally I can rev the engine and it will disengage. Has anybody else experienced this issue? I must say that I do believe the Jacobs exhaust brake was a superior system.

 

[AEdelheit]

I wonder what back pressure the stock 6. 7ISB VGT holds, I believe the Pacbrake is 60PSI ( just going off memory, not a fact) so if the VGT is less then the braking performance should be less. I do know my Pacbrake PRXB worked much better then the 6. 7's I have driven with the VGT.

 

[HBarlow]

Sorry for taking so long to reply but thanks HBarlow for the technical clarification. My fault for being simplistic in my description of the variable geometry turbocharger that is being used as an exhaust brake on the 6. 7. I should mention that I live and work in Colorado and have a Class A CDL so I do have some idea how to use an exhaust brake and other types of engine retarders correctly but thanks for the driving lesson.

Please let me rephrase my question. Has Dodge/Cummins made any design changes in 09, 10 or 11 to the turbocharger so it will perform better as an exhaust brake? Or is there an aftermarket system that could be installed on my 08 6. 7? Another problem I've recently experienced is that the exhaust brake will activate even when the switch is not on. Generally I can rev the engine and it will disengage. Has anybody else experienced this issue? I must say that I do believe the Jacobs exhaust brake was a superior system.

No, the VGT and the entire engine has remained the same since introduced.

No again, there is no aftermarket system.

I don't think it is possible for the VGT to close and operate as an exhaust brake with the switch in the off position. You think your "exhaust brake" will "generally disengage" when you rev the engine? If it was activated, which I don't believe, it would certainly disengage when you open increase engine speed. That is the nature of the VGT.

I don't. I had an aftermarket Jacobs Exhaust Brake on my '01 with manual six speed and my '08 with 48RE automatic. I believe the VGT is every bit as strong and effective.

 

[CKelley1]

call bd and get one of theirs. it makes the jacob look bad and works on the 6. 7 harvey and i do not disagree on many things but this is one. i also tow very heavy, have a cdl and class 8 trucks.

 

[ejlbuild]

I have a 6. 7 and also hear the exhaust brake come on very lightly with the switch off sometimes while sitting still or coming to a stop

 

[Hoefler]

I have a 6. 7 and also hear the exhaust brake come on very lightly with the switch off sometimes while sitting still or coming to a stop

It is used to manage intake pressure at idle when the EGR is opening. If the boost pressure was not greater then exhaust pressure, you would not get any fresh air for combustion. Also, when the engine is cold or the ambient temperature is low, the computer uses it for warm up, engine and exhaust temperature management.

 

[CKelley1]

the best thing you can do is to remove all of the egr, cooler, dpf and cat. use the smarty to program. it will enormously improve mpg and the engine will last a lot longer and be trouble free. you will really like the bd brake on the 6. 7

 

[CKelley1]

i just found this in another post. i think it was from jimw i apologize if i got it wrong.

You will need a tuner such as a Smarty S-67ME or JR and or one from H&S. You will than need blocking plates for the EGR (partial removal) or remove the EGR cooler and all hardware that uses the EGR system. The last piece of the equation is an exhaust system from MBRP or such. I am using a 5" TBE from MBRP that has been designed for a 5. 9L long bed truck. They are interchangeable with a 6. 7L, 07. 5 to an 09 truck.



Smarty on their web site does provide information on how to do the deletes using a Smarty.