(R)S4 SmokedU /-///

of outcome will I most likely see if I'm trying to rid my part throttle boost flutter? Under 10-20% throttle I see on my gauge, feel, and can even hear this annoying flutter that deviates between 2-4lbs at any level of boost. As it does this I can hear the WG's (I think that's what I'm hearing) purging exactly as I see the flutter on the gauge. The issue is most prominent when I'm right at the threshold of going into boost (say 0-10psi.) So in a drivability example, say I'm on the hi-way looking to pass slower moving traffic and I just want an extra 10mph to get past, I can't request a low level of boost in the range of 5-15psi without getting this flutter and therefore I'm relegated to a couple seconds of WOT to achieve the pass.

Once I go WOT there's never an issue all the way to RL 24lbs tapering to 22. When I'm not in boost there's no issue at all as well.

Incorporating the n75 with or without a SEL pullback will result in what exactly?

S4mig@PEB tuning

much below 22 PSI at redline. This is why PiggieSmalls went from MBC in parallel to MBC only. He doesn't seem to experience part throttle drivability problems like you're reporting with MBC only according to the numerous conversations I've had with him.

He was only reporting some minor issues with holding between 7-15 PSI in 1st and 2nd gears. He has no problem making boost below the threshold for the wastegate opening (5-7 PSI) since at that point any boost controller you use is not doing anything yet. In 3rd gear and up, he said he can pick just about any boost level and have smooth acceleration.

pitchS4

downshift. There are some part throttle/comfort issues with running an MBC in standalone, there is no denying that. But running with N75 in parallel you open up another can of worms and from what I have heard the boost will not build as quickly in the lower gears.

Besides passing people at part throttle is kinda boring anyway

S4mig@PEB tuning

Boost builds fine with MBC in parallel, no noticeable difference from MBC alone.

pitchS4

I will probably mess around with the N75 at some point but i've only been stage 3 for a couple months. For now I am just happy with it as it is

(R)S4 SmokedU /-///

Then why doesn't everyone run in parallel? What's the drawback(s)?

S4mig@PEB tuning

With MBC in parallel, you are still very dependent on the ECU's requested boost curve. If you go too far above it, you may cut throttle and/or taper excessively. If you boost too low, you may (very high probability) go into limp mode.

EdyJun

Have you considered the EBC like Apexi AVC-R? That will give you best of both words.

(R)S4 SmokedU /-///

mode in parallel if I taper below 22? I don't ever see less than 22 on the taper though.

S4mig@PEB tuning

he has not tried reducing SEL so I don't know how that would work.

But if you're fluttering boost below the threshold of the wastegate opening (5-8 PSI), I would lean toward thinking it's something other than the MBC.

If you give it a try, be sure to report back as I'm curious how it works.