DG JakeBrake 1st. test run

[CUMMINZ]

Made my first run pulling my 37' DayDreamer this week up 226 out of Marion, NC to BlueRidge Parkway. We drove several hundred miles empty with just the 3500 while we were gone. The new JakeBrake worked extremely well navigating all the hills and the 48re downshifted extremely well and was responsive. I would guess that the descent down 226 while empty, the 3500 under NO circumstances would increase in speed. The Jake would hold the truck back and actually would decel to much. While under load pulling the DayDreamer down 226, I would have to have gear lever in 2nd. with the TC locked. 1st. gear would not lockup or engage the Jake.

Especially down this hair pin turn road the travel was extremely slow and the Jake did help but I did not know what to expect and was almost disappointing. If allowed this 15k load would push me to red-line if I did not use my braking system.

I was extremely impressed with the 48re and it's downshifting. The JakeBrake did do well while on the Interstate.

The JakeBrake (JB) did change the shifting patterns of the 48re, it made the TC lock sooner. You also will have to modify your driving methods a little. If you top some hills and want to coast down and pick up a little speed you will have to keep you foot on the pedal just a little to make the computer think you are fueling. The JB would then not kick in.

All in all, I think it will be a long term investment. :-laf



Installation photos on my website below.

 

[jelag]

For the Jacobs unit to give you max performance you'll need to keep the RPM's above 2200 RPM... ... . as the rpm falls below that... the back pressure decreases... (drops well below 60 psi) and as the back pressure decreases so does the retarding HP... .



You should be able to find a retarding HP curve on their web sight for better understanding of this... .



You might be forced to to go down to a lower gear... .



With the standard PacBrake I found that the threshold was between 10 and 12K in trailer weight... . with the PRXB I find that it will hold 12 to 15 with no problem... . and that to me means no service brake down a long 6% grade... above 15K lbs of trailer weight... . the service brakes are needed... . or sometimes a lower gear... . I personally like to go down the hill a little faster than I climbed... .



Hope this helps... .

 

[Mundgyver]

The nice thing about having a Jake/Exhaust brake is that your regular brakes will last much longer. I will be replacing my original OEM Factory brakes the 3rd of Aug with over 172,000 miles on them. Mostly commuting back and forth to work.