5k leaning out

[Jorgen Karlsson]

> My 88 5ktq with the TAP chip and 3" exhaust is seeming a little
> strange.  When I went from stock exhaust to the 3" exhaust my boost level
> increased from 12.5 or so to 14.5 or 15.  The car seems to flatten out a
> bit in the upper RPM now.  Around 5500 or so.  Is this the mixture leaning
> out because of the extra (extra) boost?  Or is this the cam just being
> weak at this RPM.  Or the exhaust manifold being only so good.  Etc?  I
> just don't want to blow up my car in such a foolish way.  At least not
> yet.

You are definately running lean at that boost level. You should back of the
boost a bit and get an EGT gauge.

These engines rev very freely when everything is ok, it feels like a joke to
shift just above 6k. But without enough fuel it 'dies' at 5k. I think that
it is the knock retard that makes the largest difference.

Jorgen Karlsson
Gothenburg, Sweden