Jakes and high boost?

[Jarhead79]

I'm betting this is normal on a cm2250 but never noticed it before. Boost on hard jaking will go to 40ish it seems odd to me.

[Rawze]

(11-18-2016 )Jarhead79 Wrote:  I'm betting this is normal on a cm2250 but never noticed it before. Boost on hard jaking will go to 40ish it seems odd to me.

on the high side, but sounds about right to me. ISX has strong engine brake because it uses the turbo too.

[Rig Wrench]

(11-18-2016 )Jarhead79 Wrote:  I'm betting this is normal on a cm2250 but never noticed it before. Boost on hard jaking will go to 40ish it seems odd to me.

Stock or altered?

[Jarhead79]

Stock, stock, forgot to mention that. 450/1650 cpl 3719. 3.42 gears , 10 speed. And I do not Care for how quiet it is, and I despise the grass burner exhaust. KW said there was a update for the ecm but the owner did not think truck needed it. Also engine was inframed 12,000 miles ago, and overhead ran.

[in2trux]

12,000 miles on the inframe, it's not broken in yet.
It should improve as the miles go by.

We've seen a steady improvement since overhaul in June, starting @6, 6.5, now 7, 7.5, 8 after 30,000. That's running 77-80k up and down the hills of PA,NY.

How it's driven from day one will have a long term effect.
Once you hit 100-200k miles you're getting into the sweet spot for mileage and power.

[Nilao]

Just hit 20k miles on my Inframe. 7.7 mpg last tank. Waiting on oil consumption to slow up. Made it to 7000 miles on first gallon of oil and 8000 on my second. Full engine brake on my 871 peaks at 28 psi but the 2250 is a little different so I can't say but I wouldn't think higher boost than you would see at max power on a grade would be right, but then again you're just compressing air and not combusting fuel so it's probably fine. They do advertise it as a 600hp engine brake.

[Jarhead79]

I was told to run the he'll out of it when overhauled. What pissed me off is KW let it idle for an hour at low rpm. Oil was changed at 3,000 miles now have about 8,000 on current. 6.5 avg for 3,300 miles. I hate the black oil after you run engine for an hour on fresh oil. Idle is at 17% for the trip.

[Rig Wrench]

Rawze, do you think there is any effect on the engine wear with bost that high on the jake? I've been tryin to find the sweet spot on a 2250 jake adjustment. At 40lbs it feels almost violent

[Unilevers]

at 40 pounds is getting borderline too much. yes they work awesome there but it is extremely hard on the manifold/turbo and the head itself.

personally i would tweak it down to 35ish max.