powerful quiet engine brake

A retarder is probably worthy of consideration. I'm not at all familiar with them, but the Euro guys seem to use them quite a bit. They're external to the engine so no increase in motor noise, but they may make their own soundtrack, I haven't ever seen one in person.

 

Engine brake doesn't determine the sound, the exhaust does. Make sure you have good mufflers and you should be good.

Truck type, year, engine would be good info to have.

 

My isx is so quiet if Im talking to some one inside the truck I cant even hear it.

 

It occurs to me that Europe regulates truck weights differently than the USA. Our engine brakes weigh next to nothing compared to an axle retarder which may be something like a generator. But then, I really don't know anything about it.

http://www.zafr.com/trucktcom/retarder.htm#electric

 

I've used a retarder, actually its an "intarder" on a ZF-AStronic 12 speed, which are used in motor coaches. They had the retarders on them, they are built inside the transmission but DO NOT generate heat like the retarder on an Allison automatic. I will say this, they slow you down FAST. Rarely did I ever use my service brakes.

 

Trailer brake?? It takes a lot to wear out service brakes...

 

i run retarders on my 1693TA cats worked good as long as you dont get the oil hot. they are separate from the motor and the transmission, draw backs they are heavy and expensive plus i dont know where you can by one and dont even know if they make them anymore. to even consider on of those you are going back in time about 35 years. stick with a jacob brake and some good mufflers. lots of luck