Creeping EGT's

[Jim Green]

--- Jay Rabe <jeremiahrabe at hotmail.com> wrote:
>
> How is it possible to have "false" high temps in WOT
> - in boost on an egt
> gauge???  Think about it.
>                               Chances are your hot
> side is too restrictive
> for the boost you're running.  Anyone with egt's
> that creep in WOT (turbo of
> course) should check how high the pressure is in the
> exhaust manifold vs.
> the boost pressure.  If the difference is much over
> 10psi your hot side is
> small for the hp you are trying to get.  If the
> difference is 10psi or less
> try adding some fuel (trusting your narrow band
> O2?), or maybe some ignition
> timing.  Yes, ignition timing has a huge effect on
> EGT.
>
> I personally think ~1400' in boost should be max
> temp, idealy ~1250'.
> 1400 is good for stoich, who runs stoich in boost?


Jay, you just said what I've been thinking about all
afternoon.  I've been wondering why it would cause the
EGT to raise, and the only thing I could come up with
is too much back pressure.  I would think that a K26
hot side (The big one)on a stock MC EM would be a
relief area compared to the restrictive manifold.  I
wonder if the ECU is just slowly retarding timing in
these cases, causing the temps to go up?  I know damn
well that's what is causing the creep in my car
because I know the knock sensor is being set off by
lifters or a rubbing exhaust somewhere.  Speaking of,
time for a test drive, my new lifters have finished
setling in.

=====
Jim Green
'89 90tq EFI
http://www.geocities.com/jeg1976/car_home.html

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