[Shotimes] Re: turbos and stuff ...

[MonsieurBoo@aol.com]

"And Dave G. reminded me that even the US had tried a single turbo on  a V-6. 
Time for my
Homer Simpson  DOH!"
 
Well now, it wasn't a "V" but let's not forget that the 'Vair had a single  
turbo on a pancake 6 back in '62.  That was on a 145 cid (2.4  litres) and it 
boosted the rated HP from 80 to 150.  The 164 cid (2.7  litres) came in '65 and 
that one put out 180 rated ponies.  It was a hot  lil' number but sure enough 
after awhile, people started complaining about turbo  lag just like now.  
 
On the "macro" scale the Corvair was easy enough to plumb for dual turbos  
because of being a pancake, everything basically mirror image on each side of  
the engine and lots of room to fit stuff in.  But long story short, we  found 
out that despite the lashed-together look of the whole setup, the GM  engineers 
actually did their homework pretty well when they designed the intake  
plenum, snakes, and the manifold passages cast into each head.  Had things  figured 
out so reversion pulses from the intakes slamming shut on the  "near" 
cylinders would shoot an extra shot of mojo out to the "far"  cylinders to keep 'em 
from running leaner.  Just short-coupling a turbo to  each head actually messed 
that up considerable by changing the intake volume and  resonant frequencies 
therein.  In fact after much experimentation, it  turned out that a Holley 390 
4v pressurized ("blow-through" mode) by a  single turbo, sitting on top a 
plenum with a runner tube to each  head like the factory setup, was the big kahuna.
 
I guess the moral is, "In theory there's no difference between theory and  
practice ... in practice, there is."
 
Cheers,
Mark LaBarre
94 atx 125k