Engine/Transmission (1994 - 1998) Installed the Pacbrake Maxflow PRXB

[DValentine]

I finished with the install yesterday. I had to modify the wiring harness as it was too long for where I put the components. I searched the forum here to see where guys were mounting the components. I made my own bracket for the air pump, putting it on top of the alternator bracket perpendicular to the engine toward the passenger battery. The air tank I put on the drivers side, the solenoid I put on the passenger side just inside of the hood hinge.



I bought the brake from Source Auto, along with a 4 inch exhaust. PacBrake does not (at this time) have a 4 inch kit to go with the brake housing. Rip had just installed one on a 24 valve and made up some tubing parts for me to modify his exhaust kit (went from 3 to 4 inch just off the turbo housing) to the new housing (Pacbrake) that bolts to the back of the turbo, replacing the outlet (cover) of the waste gate.



Max Flow PRXB



I had to fit and weld 3 pieces together to make the down pipe.



I am looking forward to hooking up the fifth wheel to see how it feels.



I don't know how to describe the sound it makes. Like a dog in mid sneeze? Certainly not the cackle of a 855 Cummins with stacks and a real Jake...







Dave

 

[CTD12V]

Certainly not the cackle of a 855 Cummins with stacks and a real Jake...

Oh man, if only our trucks sounded like that . . . nothing better.



I'm really interested in your EGT results. Was there much of an improvement? The Maxflow design sounds great, but I wonder how it works in the real world.



So is the back flange of your exhaust brake (where the downpipe clamps on) 4" or 3"?



CTD12V

 

[DValentine]

The exhaust flange is 4 inch. The kit came with a 4 to 3" adapter for 3 inch pipe.

I have not put the fiver back on so the egt's are just the truck only... .

Previously I could run the egt over 1300 in a good pull in 4th and had to get out of the throttle. I put on a HX 35/40 still running the 12cm2 housing. I figure I lost about 300 degrees. My findings are not scientific, by any means. But I can, with out the trailer, make a hard run in 4 and 5th and the egt's are just over 1200* as I run against the Gov. (I have since, put in the 3k springs)

The 4 inch exhaust and the Maxflow housing resulted in another 100* or so drop in the temps.

I will have the trailer on in a week and will report back as to how the sum of the parts work with a load.


I am happy with the system, and what it did for my exhaust temps.

Dave

 

[CTD12V]

Cool. Thanks for posting back. I'll look forward to hearing your results with a trailer. I really would like to get one of those brakes and a 4 inch exhaust. It's been on my dream list, but I'm afraid it's still a ways off. EGTs are a lot bigger of a problem here where I live (about 4,000 ft higher than Laurel), so I was very interested when I first saw that Pacbrake had come out with the Maxflow design.

 

[DValentine]

The turbo made the biggest difference. I see you have stage one DDPs. I have stage 2's, the stock plate is forward, AFC is loosened up. It was too hot with the fifth wheel behind. We took a 2500 mile run this summer to the West Coast. I had to keep getting out of the throttle. I was running 34 pounds boost, but EGT's were spiking. Too much fuel... Not enough turbo... Now it will be better.

The exhaust brake feels like a mild push on the hydraulic system. It is consistant from upper rpm range to 1500 rpm.


Dave