EGO sensors

[Edward C. Hernandez]

Todd King wrote:
>Usual practice w/ the headers (which seem to hurt performance, BTW) is >to use a heated replacement sensor.
>   These can be had for about $25 from the General these days.

A couple reasons headers may not have worked for you:
1) most aftermarket off the shelf headers aren't properly
designed(primary lengths and diameters, collector volumes, etc). For
many applications, they are better than stock because stock is so bad,
but in your case, they weren't. Turbo Buicks are pretty nice motors, and
perhaps they designed an excellent stock exh manifold.
2) don't know if stock Buick exh manifolds are cast iron, but if they
were the exh gasses they pass to the turbo are hotter than exh gasses
from uninsulated headers. Were yours wrapped?
3) path lengths from exh valve to turbo should be longer for headers
than manifolds, exacerbating problem 2.

Hey, can you give us a part number for the $25 GM HEGO?

Dave Crocombe: Best power is made richer(say, 12.5:1) than
stoich(14.7:1), not leaner(18:1 per your note). I doubt your brother
actually ran this lean or you'd have given up drag racing by now, having
blown every motor as you went througth the traps, particularly with
nitrous.

Ed Hernandez
Ford Motor Company
ehernan3 at ed8719.pto.ford.com