Real Jake brake

[abner99]

Ok so got into a weird discussion the other day on what it would take to put a real Jake brake in our cummins I'm not talking about exhaust brake. Talking about the real deal like in a semi. Is it just impossible because the design or what. Figured I'd ask the motor heads in the forum. Thanks 

[Me78569]

they make them for 6.7

http://www.thoroughbreddiesel.com/pacbrake/loadleash-engine-brake.htm?popup=n&gclid=CjwKEAiA0fnFBRC6g8rgmICvrw0SJADx1_zA6PqZ-BPAAG-LMXEjFX7EcCNpGe8UHaBQXJ0gZeVF3BoCrvnw_wcB

 

I know someone has a "prototype" for a 5.9 but I am guessing it would be WAY to much to bring to market for the cost and number of people that would buy it.

[abner99]

That is amazing. Doesn't really have the bubbling sound but ohh well. Why don't they factory that instead of exhaust brake. I would love to have a engine brake. 

[Me78569]

cost.

 

The EB works well enough, I can generate 50 + psi of backpressure using it.  

[Mopar1973Man]

Here you go...

http://www.thunderbrake.com/

 

 

[abner99]

I love it too bad they are not selling 

[AH64ID]

13 hours ago, Me78569 said:

cost.

 

The EB works well enough, I can generate 50 + psi of backpressure using it.  

 

With my cam I hit 75 psi!!!! I'm glad I have upgraded valve springs. 

 

 

 

I have always thought that the loadleash would work with a 5.9, but I haven't tried. 

[Me78569]

Mines still coded to limit to 50 psi.  I have 104 #'rs in it now, just haven't updated my turbo code yet.  

[abner99]

Seems like you common rail wins again

[KATOOM]

Its my understanding that the Pacbrake "LoadLeash" is not a stand alone device but rather works in conjunction with the VGT turbo.  And no, its not available for the 5.9 engines.

My 10+ year old Pacbrake exhaust brake works great though.....

[abner99]

Seems like a lot of people like them. That's why I didn't think Jake brake existed 

[KATOOM]

Not sure what you mean.....  The "Jake" brake is merely the nickname given to the old Jacobs system.  People mistakenly use it when talking about all exhaust brakes or engine brakes.  Kinda along the same way people refer to tissue paper as "Kleenex".

[AH64ID]

2 hours ago, KATOOM said:

Its my understanding that the Pacbrake "LoadLeash" is not a stand alone device but rather works in conjunction with the VGT turbo.  And no, its not available for the 5.9 engines.

My 10+ year old Pacbrake exhaust brake works great though.....

 

That's how they advertise it, but unless I am missing something I am not sure why it wouldn't work on a 5.9 with a PXRB unless the PXRB cannot maintain backpressure at 60 psi. The engine doesn't care if there is an exhaust brake or a VGT on the manifold as it just reacts to backpressure. Based on how they describe it's operations it should work with a PXRB....unless it's too much backpressure, but that can be controlled with bigger valve springs :-)

Edited March 10, 2017 by AH64ID

[KATOOM]

I also remember hearing/reading something which states that the LoadLeash wont fit on the 5.9 merely due to lack of space.  I would presume thats only addressing the Dodge Cummins application..... 

 

Also, excluding the fact that the LL ties into the ECM, is the 6.7 head the same as the 5.9?

[AH64ID]

I know that people use 5.9 heads on 6.7 blocks so I don't see why it wouldn't fit. 

[Wild and Free]

And another thing is the amount of complexity it adds to the overhead of the engine. A whole other level of adjustments and it would all need to come off to set the overhead and or remove injectors on the 24v engines. Engine brakes are a PITA from a maintenance stand point, the exhaust brake is the simpler and most practical on a pickup.

[pepsi71ocean]

The biggest thing I see, is the displacement, most semi engines are 15L motors, almost 3x the side of our trucks. when you turn the jake up, you increasing the length of time the exhaust valve is open, and creating a vacuum inside the cylinder that gives you the retarding hp you need.

 

the new DD15's in our trucks suck, they have VGT addon's to the jake's and they don't do the same, like the older Detroit's did.

[abner99]

On 3/9/2017 at 7:22 PM, AH64ID said:

I know that people use 5.9 heads on 6.7 blocks so I don't see why it wouldn't fit. 

 

I never knew that is that real true? So essentials you could put the load leash on a 5.9 just more up keep, work, headache, and ecm ties. when the exhaust brake PXRB is a far better way

[AH64ID]

The 6.7 with its VGT EB is supposed to be more retarding hp than the 5.9 with an EB. The load leash adds to that, so a loadleash with a PXRB would be substantially more than a PXRB alone. 

 

The load leash works in conjunction with the VGT EB, so it's not a one or the other type thing. 

Edited March 14, 2017 by AH64ID

[Mopar1973Man]

I tend to agree with most here that the exhaust brake is more than enough and very simple. For us manual transmission owners with exhaust brake it very capable of creating lock up conditions of the rear axle on slick surface like mud, snow, ice, or even wet highways. Even if you did have the ability to be like AH64ID the more pressure you can hold back using him for the example 75 PSI is just that much greater braking force. Even with just more or less stock ISB engine and Jacobs exhaust brake I've extended out my brake pads to at least 180k miles. Next due date is 360k miles and I'm currently at 290k miles and better than 50% of pads left yet. Even with that said I've got the ability to get the rear tire hopping and skidding with just the EB and factory 60 PSI exhaust pressures. Over the years I've learned on how to use my gearing to control the amount of EB strength. So need light amount row a gear up. New more row a gear down. Again I speak from a 5 speed manual perspective where a 4 speed auto is way different story being the lockup controller and only 4 gear making it rather challenging to get full use like a manual where I can continue to down shift to first pulling the truck to a near stop which an automatic trans can't do typically they EB only functions in 3rd and 4th which provides TQ converter lockup. 

Edited March 14, 2017 by Mopar1973Man