Question on compression ratio vs boost
Thread Starter
Race Director
Joined: Jan 2006
Posts: 18,396
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Question on compression ratio vs boost
Please school me on lowering the compression ratio, say from 11 to 9.5 effect boost?
My builder says I should consider. 9.5 cr piston and up the ProCharger boost to the 15 pound range.
Is there an advantage to do this vs an 11 cr and a 12 pound boost?
My builder says I should consider. 9.5 cr piston and up the ProCharger boost to the 15 pound range.
Is there an advantage to do this vs an 11 cr and a 12 pound boost?
Racer
Joined: Aug 2013
Posts: 340
Likes: 15
St. Jude Donor '15
This is a controversial topic.
In my opinion you will have a power limit with the fuel no matter how you get there (compression or boost). Your timing in the tune will change between the two compressions but I don't think you will have a huge power benefit with one or the other. If you run higher compression you will have better off boost throttle responce althought I noticed very little difference between 10:1 and 11:1 on my car. A good tune, good parts and constant fuel quality are the key. Again, there are gonna be "engineers" that will give you tons of theory on how to pick but I thing the benefits or trade offs are minimal with the options you've given.
In my opinion you will have a power limit with the fuel no matter how you get there (compression or boost). Your timing in the tune will change between the two compressions but I don't think you will have a huge power benefit with one or the other. If you run higher compression you will have better off boost throttle responce althought I noticed very little difference between 10:1 and 11:1 on my car. A good tune, good parts and constant fuel quality are the key. Again, there are gonna be "engineers" that will give you tons of theory on how to pick but I thing the benefits or trade offs are minimal with the options you've given.
