MPD Kit S363 Turbo Surging

williamallen13 · Feb 7, 2016

Since installing the S363 turbo kit on my 2011 6.7 I've noticed at highway speeds like 65+ the truck seems to surge or slightly jerk forward when I let off the accelerator to coast. I've tried to ease off and it still does it a little and I would say it does it most of the time. Any suggestions or is this something I should be concerned about?

drunk on diesel · Feb 7, 2016

compressor surge isn't something you'll feel in the truck... it certainly won't pull the truck forward

confused as to what you're actually experiencing

BOHICA256 · Feb 7, 2016

My bet is transmission. Mine does it too. Kinda weird. Feels like there's some slop or slack when you let off of the accelerator. Mine doesn't do it all of the time but it does it pretty often. And it's always been above 55mph

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Six_Sloww · Feb 7, 2016

Did the tuning change when you swapped the turbo?

Sounds like you may be confusing turbo surge and throttle surge.

Turbo surge is an audible issue that you wouldn't likely feel, this happens either when the turbo is way out of its efficiency range (surge) or you chop the throttle hard (bark).

What it sounds like you are experiencing is more like a throttle surge which is likely related to tuning.

BOHICA256 · Feb 7, 2016

Nailed it^^ if I remember correctly my MPD tunes didn't do it. But the MPD tunes shift way too hard. And my Ghead tunes are too soft.. and will flare every once in a while. But the Ghead tunes are the tunes I run and it will do the throttle surge. Not sure what tuning the OP is using.

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williamallen13 · Feb 7, 2016

What the truck's doing is when driving steady at 65 or so and I let off the accelerator the truck sort of lunges. Almost like I was giving it then gave it some throttle and let off except I'm just letting off. Probably the transmission and it does only do it at like 65 or so and only in 5th or 6th gear. Is this something to be concerned about or is it normal?

I've also noticed the truck's downshifting more from 6th to 5th on the highway. I do have 20x12's and 35 mt's.

BOHICA256 · Feb 7, 2016

What your describing is what my truck does also. Just when you let off of the accelerator. You can give it throttle, just enough to hold the speed and then let off and it jerks? What tunes are you running?

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williamallen13 · Feb 7, 2016

I have an sct tuner with PIP tunes right now.
How do you like the 367 and how does it spool?

BOHICA256 · Feb 7, 2016

Spools fine, I love it! I drive mainly highway so the top end is very nice when passing people on two lane roads.

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6.7powerstrokeguy · Feb 7, 2016

mine also does the lunge with h&s and stock trans tuning. 2011 f250

williamallen13 · Feb 8, 2016

BOHICA256 said:
Spools fine, I love it! I drive mainly highway so the top end is very nice when passing people on two lane roads.

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What boost levels are you seeing and how fast does it spool?