Re: Where is BAR Measured?

[steveb@newkla.kla.com (Steven Buchholz)]

> On Wed, 6 Sep 1995, Michael Spiers wrote:
> 
> > Got and installed the factory InterCooler hose from Linda.  My dash display now
> > reads 1.8 BAR if I have my foot on it, whereas with the straight silicone hose
> > I only showed 1.7 as a high.  HOWEVER, there is a NOTICEABLE performance drop
> > with the stock hose on there! The car doesn't get up and go as well as it did
> > with the other hose.  If I'm reading more presure now, how come the
> > acceleration isn't as good?  I'm baffled...
> Mike,
> 
To which Graydon Stuckey replied:
>
> 	I also noticed that my pressure dropped when I installed the 3" 
> hose.  I think that since there is less resistance to flow, the pressure 
> drops.  With the 3" hose, you get more flow at a lower pressure, IE you 
> have a more efficient system, and hence, the same performance (or more) 
> with less pressure.

Interesting observations.  I would agree with Graydon if the pressure was
measured upstream of the restriction, but I believe that the pressure is 
measured in the manifold itself.  This would lead me to believe that the
reduction in pressure was not due to lower restriction with the 3" hose.
I am wondering if the dynamics of pressure to the wastegate has changed
in a way to reduce max power.

JT!
Steve Buchholz
s_buchho@kla.com