upper boost limit for stock MC-1 internals?

[Ken Keith]

Hello List,

I was trying to find something on this in the archives, but wasn't 
sure what to search for.

I know that some listers have experimented beyond the standard, 
1.8 bar, chipped boost levels.  Also, the reason 1.8 bar is a 
common level of chipped boost is because it's been proven not to 
break anything.

I was wondering just how conservative this increase is.  I know that 
there are basically three things that limit boost:  pinging, excessive 
heat in the combustion chamber, and compressor efficiency.  Is 
there anything else?

I'd like to get an EGT gauge, and some kind of a driver warning 
device for pinging.

If the combustion chamber is kept low enough not to melt stuff or 
break down the oil, and pinging is prevented, is there any other 
reason that boost can't be increased?  I'm sure there is, I just want 
to understand it.

I own and have read (tho' only once) Maximum Boost by Corky 
Bell.  I don't recall any other threats to longevity.

My 5kcstq current reads about 12psi on the Autometer gauge.  
That seems to convert roughly to 0.8 bar above atmospheric.  Btw, 
I have a little unit conversion program, and bar and atmosphere are 
two different things.  Atmosphere is given as 14.50377psi and bar 
is 14.69595psi.  Are our bars, bars?

Question 2:  What is the weakest link in the engine?  What is the 
first to go?  I do understand the relationship between going lean 
and going ka-blooey.

Thanks,

Ken