2015 boost differences

[ramonpowerstroker]

Haven't started a post in a while so decided to throw this out there.


For those with 2015 and ONLY 2015 with the ******s and stuff what boost does your truck run?

I've noticed mines sometimes jumps from 25 to 35 depending on the way the truck feels like doing.


For example:
Crusing down the highway I lock my transmission in 6th and put the pedal to the floor, boost get to 25 and stays at 25 until I let off.

Again, crushing down the highway again, I lock my transmission again and put the pedal to the floor and now it's pushing 35.


Also I've noticed as I become to start slowing down, my exhaust vanes close and make the truck feel like the exhaust brake is on. It slows the truck down as I'm coasting and pushing 8-10 psi of boost.. I push the exhaust brake button to turn it on and it seems like it turns it off?

Has anyone else noticed this? My 2015 acts like a different animal in these 2 scenarios and the always active exhaust brake is a new thing and its tripping me out.


Trucks kem tuned as well

 

[Notneb]

I know the exhaust brake is hit or miss with tuning. A lot of guys have had that problem where it's on when it's supposedly "off" and visa versa. As far as boost goes, I just have the factory gauge to read it and it buries the needle everytime I get on it full throttle above 1500 rpms.

 

[drservo]

My exhaust brake doesn't do much after I tuned it, I can't tell any difference between it and Tow/Haul. How are KEMs tunes? I didn't know he was tuning 15's?

 

[ramonpowerstroker]

Besides having these issues just transmissions shift points aren't the greatest, but the truck runs so I can't complain. Just don't understand why my boost is acting funny

 

[c63 AMG]

I know the exhaust brake is hit or miss with tuning. A lot of guys have had that problem where it's on when it's supposedly "off" and visa versa. As far as boost goes, I just have the factory gauge to read it and it buries the needle everytime I get on it full throttle above 1500 rpms.

So you're seeing boost above 40? How many lbs of boost can the stock internals hold? Don't think I've seen over 20 if that on the stock tune.

 

[Notneb]

Doubt it, I'd say around 35psi. The factory gauge isn't very accurate. My 2012 would bury the boost gauge too, yet the mini maxx would read 34-36psi. The stock internals will handle that boost fine, as long as it isn't coming on at low rpm. Rods start noodling when you get too much torque, too fast, especially at low rpms.

 

[UNBROKEN]

Mine CS has recorded a max of 36.

 

[Morgan@Midwest Diesel & Auto]

With the bigger turbo I could see almost 50 on a hard fueling tune... With some of the early tunes that were crude it would hit 40 on a stock turbo.

Honestly with a stock turbo 30-35 is optimal.


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[ramonpowerstroker]

Any reason it would sometimes only boost to 25 psi? Just a weird question I've noticed.

 

[Captaincworley]

The last time I was out at the track my Max Boost was 38-40. This past time I was home I ran it hard a few times and Max was 36. It was Hot as heck tho this last time I was home.
So the 25psi you were getting, Was that Peak?
I haven't had the issue of the Vanes closing on me when slowing down.

Charles

 

[ramonpowerstroker]

Yes sir it peaks at 25, and the exhaust brake is definitely on. You push the exhaust brake button to turn it on and it actually turns it off. Strange..

 

[Morgan@Midwest Diesel & Auto]

Yes sir it peaks at 25, and the exhaust brake is definitely on. You push the exhaust brake button to turn it on and it actually turns it off. Strange..

There are a lot of tables in there that could be affecting your output at different conditions. The exhaust brake function is basically the same as everyone else's tunes. The disabling of the egr system does the same and with about the same results on all trucks. Some strategies differ but your not the only one seeing that exact same thing.


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[ramonpowerstroker]

Thanks Morgan for the reply, just to clarify the truck runs tip top, just wows me how these truck react to a tune..

 

[borsky]

my truck running the k#$ tunes peaked boost around 35, I'm running I@P now, i might hit 30 psi locked in 6th on the street tune which is completely smoke free. Mine does the exact same thing with the exhaust braking which I kinda like. If i turn it off with the switch it quits building boost. average boost while accelerating hard id say is 25ish. the shifting is spot on with I&P's tunes though. much happier then K#$