Trying to lower my CF's would love some input on fueling.
04-27-2006, 04:47 PM
#11
Checked ~10 different 031 logs from 3 *different* S4's...
and 'every' single one had higher post cat numbers and only S4 had the non-fouler mod. All were in good running condition.
Dunno guys...
Dunno guys...
04-27-2006, 07:06 PM
#12
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I have a HPXS MBC, it has 2 adjustments, I can turn the boost up or down and even get
it to hold more boost, but I cant eliminate the spike... I was told that is a condition of MBC only and possibly waste gate adjustment.
If I am wrong please tell me my MBC is not working as intented and I should try another.
If I am wrong please tell me my MBC is not working as intented and I should try another.
04-27-2006, 07:08 PM
#14
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there shouldn't be a spike with mbc only.....
the mbc in most cases will react quick enough to eliminate any potential boost spike, this is why a lot use it in parallel with the N75 because it can prevent that initial spike. You should be hitting a certain psi and then most likely tapering from there since you are running the mbc only setup.....depending on actuator adjustment as well though.
So you can't get boost any lower than 23psi?
So you can't get boost any lower than 23psi?
04-27-2006, 07:18 PM
#15
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My problem is holding 21PSI and keeping my spike low. Just doesnt
seem doable. If I want to do 21-22PSI hold its going to spike 24 or so.
Turn the hold adjustment up, turn main boost down, below 24PSI I loose hold.
Turn the hold adjustment up, turn main boost down, below 24PSI I loose hold.
04-27-2006, 07:38 PM
#16
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that's an issue with the mbc only setup IMO
the mbc doesn't have the ability to flutter or control the acutuators like a selenoid does (ebc or N75). It's either fully open or fully closed and once the mbc slams the wastages open it's very tough for them to close again once you've got that much exhaust gas pressure in the turbine housing.
04-28-2006, 04:16 AM
#19
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here's my MBC+N75 curves for ~13psi and ~18psi ...
<img src="http://ctny.audiworld.com/mark/s4/misc_data/bAF_MBC13psi.gif">
<img src="http://ctny.audiworld.com/mark/s4/misc_data/bAF_MBC18psi.gif">
<img src="http://ctny.audiworld.com/mark/s4/misc_data/bAF_MBC18psi.gif">
04-28-2006, 08:54 AM
#20
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Really all the stage 3 S4's that are MBC only + TCD spike that I know of;
At least 3-4 PSI. My buddy K04/RS6 spike 26-27 and hold 24.
Another friend with K04 and Revo code does same thing.
I just figured it was normal.
Another friend with K04 and Revo code does same thing.
I just figured it was normal.