Dan,

Here are some notes from my early tests on my 617.950 engine:

"We used a Snap-On Vacuum/Pressure Gauge for this test. We attached a fitting into the plug at the front of the intake manifold. This allowed us to retain the Overboost Protection Circuit. The air filter was left in place.

At an idle speed of 875 rpm, the needle fluctuates slightly, which gives you an idea of how sensitive this instrument is.

Snapping the throttle wide open (and quickly releasing it) indicated 7-8 psi on the gauge. Rpm peaked at about 3200 during this portion of the test.

As we took the car out for a drive, we noticed the boost gauge imitated the movement of the tachometer. We were registering about 3-4 psi by 1200 rpm and it continued to climb in relation to engine rpm very rapidly.

At a 65 mph cruise, we were developing 6.5 psi at an indicated engine rpm of 3000. Opening the throttle fully, instantly swings the needle past 10 psi of boost.

We then conducted the WOT test, holding the engine against the brakes at 4000 rpm in the second speed range. We recorded 14.5 psi of boost pressure...."

Hope this helps....Robert

__________________
Did you just pass my 740 at 200 kmh in a 300SD?????

1978 300SD 'Phil' - 1,315,853 Miles And Counting - 1, 317,885 as of 12/27/2012 - 1,333,000 as of 05/10/2013, 1,337,850 as of July 15, 2013, 1,339,000 as of August 13, 2013



100,000 miles since June 2005 Overhaul - Sold January 25th, 2014 After 1,344,246 Miles & 20 Years of Ownership