marc wiese wrote:

This chart was done on a piston engine with a Spearco IC 3.5" x 8" x

20".

Ambient temps are 55 F.
Input temps to turbos are 88 F, not cold air intake.

boost   air temp air   temp air temp
in PSI  before turbo   after turbo     after IC
2       88 ° F          110° F          55° F
7       88 ° F          170° F          66° F
15      88 ° F          227° F          80° F
20      88 ° F          294° F          88° F
27      88 ° F          310° F          101° F

Keep in mind these Shelby nuts are throwing 30+psi into 2.2l and 2.5l
fours. YEOW. (Usually on stock bottom ends too!)
For some, that intercooler isn't big enough. Here's a link to what is
possibly
the best intercooler deal *ever*:
http://webpages.krausonline.com/spaul/intrcool.html
Maybe a bit big for an FD, but for the price, it could be cut down and

the

end
tanks modified.

The max limit without detonation on a Allison turbo P38 engine was 130

degrees F IIRC.

Paul Lamar

tommayer wrote:

Paul,
    For what it's worth to rotaries, a Lycoming engineer told me that on
their angle heads, with 8.7:1 or slightly higher compression,  100 F at the
fuel controller is absolute maximum acceptable.  Tom Mayer

Thanks for the data point. That adds to the evidence that the best way to 
prevent detonation in a turbo engine is monitor the intake manifold temperature.

Paul Lamar
 
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