boost presser and power gain

[Mike Pitts]

>>And how march reduction of compression ratio will 
>> needed?  

8.0:1 is a good ratio for an engine which will see 14-18 PSI of boost 
on 93 octane fuel.  If you run racing fuel (say 116), you can run about 
25 PSI.  Provided your engine can take the additional HP (there will 
be ALOT at 25 PSI), and your injection system can properly fuel the 
engine.  If you go lean or otherwise detonate at these boost levels, 
kiss your engine goodbye.

You can also reduce timing as you add boost.  This will allow you to 
run higher boost.  Speaking of spark, you will need a hotter spark and 
smaller plug gaps, otherwise the boost will "blow out" the spark.

It's really tough to say how much power gain you get.  My personal 
rule of thumb for a 3.8L V6 has been 10 HP for every PSI of boost.  
I am sure this varies greatly depending on the base engine 
parameters (VE and such).

All of this is just my opinion...YMMV

Hope this helps,
-Mike
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Mike Pitts
Delray Beach, FL
mpitts at emi.net
http://www.emi.net/~mpitts/mike.htm
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