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Sheep on the hood...
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Discussion Starter #1
I have a few simple questions about compression.

If I have a 10:5:1 compression and run 7 psi I should be fine correct?
What will happen if I keep my boost at 7 psi and lower the compression to 8:5:1 ?
Will my horsepower go down and would I have to increase the boost to a higher number to get the same results?


Thanks and sorry for the dumb question.
 

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Very good question, I would also like to know the effect of lowered compression at 7 psi, compared to higher compression at the same 7 psi. I guess we will have to wait on this one..
 

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Higher compression will produce more hp per psi whereas low compression will do the opposit. However is is recommended to lower the compression if your aiming for high hp.
 

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The result of drop the compression from 10.5 to 8.5 and keeping the 7 psi of boost , is less power.
It possible running 7 psi on a 10.5 compression, but by doing this you must lower the timming 4 to 5 degrees to prevent detonation.
 

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Sheep on the hood...
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Discussion Starter #5
ramphis said:
The result of drop the compression from 10.5 to 8.5 and keeping the 7 psi of boost , is less power.
It possible running 7 psi on a 10.5 compression, but by doing this you must lower the timming 4 to 5 degrees to prevent detonation.
What if the car is VVTi
Are you able the lower the timming 4 to 5 degrees?
 

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blur2ed.com
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If you take a stock NA, and drop the compression from 10.0 to 8.5-1, you are looking to lose approx 40rwhp. You need lower compression for higher HP apps though, as with lower compression, you can run more boost safely, and crank that biatch up!
 
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