<VV> RE: Ed's strange turbo behavior

[Jim Burkhard]

One big question ... look at the gauge face and tell us:
1) Does it read "psia" or "psig"?
2) When you shut the car off, what number does the boost 
gauge read?

This is a (relatively) unmolested sorta stockish car, right? 
Boost should be limited by the restrictive Carter YH carb. 
If you switch to something else, you can make more boost, 
but at these pressures (if they are gauge pressures and not 
absolute pressures) you will be scattering stock cast 
pistons even if you somehow keep it out of spark knock (at 
those gauge pressures, you need water injection and/or 
intercooling and/or active knock sensing and spark retard, 3 
modifications it seems you are implying are unlikely.

My vote is that the gauge reads psia.  Subtract off 14.7 and 
you get gauge boost pressures of between 5 and 11 psig ... 
right where they should be on a healthy stockish Vair.

Jim Burkhard

Arjay Morgan wrote:
> Gentlemen:
>    
>   A friend known to some of you, Ed Lang, formerly of Michighan, now of Florida has a meticulously restored Spyder which is the envy of all who see it.
>    
>   Tonight in conversation he related this story to me and wondered what kind of response it would get from my fellow VVers.
>    
>   He says that he's measured the boost from his standard 150 turbo at between 20 and 26 lbs. pressure. So much, in fact, that it's pushed the tube carrying the boost off its mountings. He has measured, not with the stock dash gauge but with a real 0-100 lbs/sq/in pressure gauge. Concurrently he's used a real vacuum gauge to determine that at 70 mph his engine is pulling between 15-17 inches of mercury measured on an outboard vacuum gauge.