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b930 b930 is offline
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Join Date: Apr 2011
Posts: 235
Originally Posted by RarlyL8 View Post
Yes boost threshold is established on a flat road in 3rd gear as the rpm where the needle begins to move.
Full boost should be rock solid at the pre-set point nomatter where you measure it. Overboost from ill designed header waste gate pipe will manifest as sustaining boost levels above the preset. Boost spikes are different and are typically measured before the throttle body where a snap throttle event will momentarily back up the boost pressure into the intercooler as the BOV opens.
Based on your definition of boost threshold, in 3rd gear my boost gauge shows positive anywhere from 1500 to 1700 rpm. From as low as 1650 rpm the boost gauge moves steadily north. From 1200 to 1700 it shows .15 bar. Its a bottom end stomper this set set up and I really like it.

Porsche 930 gt35 turbo boost onset in 3rd - YouTube
1988 930: 3.5L 100mm LN slipins, LN FFA rods, Supertec studs, GT3582R with T4 1.07A/R twin scroll housing, RarlyL8 equal length divided headers, dual Tial MVS 38mm WG's, Carrera 3.2 heads with 993 big valves. 964 Cams, full bay IC, KEP st1 clutch. PE3 sequential ECU with 750cc EV14 injectors, CoP twin plugs, J&S Safegaurd, Aquamist HSF3 water inj. Wavetrac LSD.

Last edited by b930; 06-30-2012 at 04:11 AM..
Old 06-30-2012, 04:07 AM
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