Perth-WRX.com - Boost Drop Off

Perth-WRX.com (http://www.perth-wrx.com/vb/cmps_index.php)

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- - Boost Drop Off (http://www.perth-wrx.com/vb/general-subaru-discussion/4584-boost-drop-off.html)

i have asked a million people this question but i will ask it again just to reassure meself :D

currently i got a manual boost controller in me car and runnin 1.1bar and it will boost to 1.1 for 500 revs then drop to 1 bar then past the 5500 mark it will further drop to .9 bar........ hmmm.... its not somethin wrong just askin is this a case of the turbo (td04L) not able to hold the boost or crappppppppy mbc??

thanks dudes
mark

mr_psi
Sounds simple to me...you have a manual boost controller that provides an offset or additional boost value to the oem boost, not a fixed value.

[B]The standard Rex ECU runs a falling boost curve.[/B] Meaning at higher revs it drops boost. Because if you ask a TD04 to push 1.3 bar at 6000 rpm its going to be an ugly (hot) result. They normally taper to about 0.6 / 0.7 bar at redline for saftey.

Your MBC valve would be set to trick the system to run say 0.1 or 0.2 bar higher than original boost values across the entire rev range. Have a look at some dyno plots of standard cars on RPM/Boost if this explanation is not clear.