Engine/Transmission (1998.5 - 2002) Jacobs Exhaust Brake

[Silver_Ram]

In searching for information on exhaust brakes, I have seen it mentioned a couple of times that there is a noticeable power loss with the Jacobs brake.



How much of a power loss? Is it like the difference between having an Edge EZ installed & then taking it back off?



The more I read from previous posts, the more I get confused. I also noticed that alot of the previous posts are from a year or more ago, & technology changes all the time.



I spoke with a local dealer & was told the brake wouldn't work with 4" exhaust, but couldn't tell me why. My exhaust is bolted up to the stock exhaust elbow with no problems.

 

[RustyJC]

In searching for information on exhaust brakes, I have seen it mentioned a couple of times that there is a noticeable power loss with the Jacobs brake.



How much of a power loss? Is it like the difference between having an Edge EZ installed & then taking it back off?



The more I read from previous posts, the more I get confused. I also noticed that alot of the previous posts are from a year or more ago, & technology changes all the time.



I spoke with a local dealer & was told the brake wouldn't work with 4" exhaust, but couldn't tell me why. My exhaust is bolted up to the stock exhaust elbow with no problems.

See my dyno results below - these were achieved with a Jacobs e-brake installed.



The primary downside to the Jacobs e-brake, IMHO, is that you are restricted in your ability to upgrade turbochargers. The Jacobs e-brake replaces the stock cast elbow at the turbo's exhaust housing discharge, so if you change to a 4" or larger outlet turbo, the Jacobs e-brake can't bolt to it. You're pretty well stuck with an HX35 hybrid as the largest turbo upgrade unless you're willing to change out the e-brake.



Rusty

 

[amillstream]

If your exhaust elbow is still stock you won't have any problems. You just take the stock elbow out and put the brake in its place. I have a pacbrake and didn't notice any difference in performance. A friend of mine has a Jacobs and no performance loss there either.

 

[Silver_Ram]

Thanks for the information...



How hard is the installation of the brake?

 

[Sixpack]

No power loss here either. The only thing I noticed was the egt's climbed ALOT faster with the brake installed. After I installed 4" exhaust and a AFE Proguard 7 all is well again. The install took me about 4 hours taking my time and doing a neat job. Fairly staight forward. Good luck, Phil

 

[amillstream]

Thanks for the information...



How hard is the installation of the brake?

Unbolt exhaust elbow, bolt on brake. Very simple (well its kinda hard getting to the bolts on the downside of the elbow but I just put three wobble extentions together and went up from the ground, made it pretty easy. ) The hardest part is the wireing and thats not hard. For the vaccum, I tapped into the lines running across above the back of the motor. . I don't know about a Jacobs but you can get detailed instructions for a pacbrake off their website. I also suggest getting a shifter switch, makes it a lot more convienient.

 

[PKleine]

I just installled a Jacobs exhaust brake a couple of weeks ago. I have not noticed any performance drop. I did notice one change. With the camper on, I had a drone under load at highway speeds, 1800 - 2000 rpm, that is now gone with the exhaust brake installed and I have the stock exhaust. I mounted the rocker on/off switch, supplied with the kit, on the gearshift using wire ties. This is temporary until I get a real gear shifter switch. The installation was simple, only took a few hours.



PK