92dxeg wrote:well i was always told it was too high and as of right now i am like 12.1 i was told buy the shop that is buiilt my block but thats with a stock b16 head i am building a gsr head to put it on would that bump up the cp ratio more?
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it depends on the cc of the chamber. if the b16 head is stock unmilled it lowers compression on b18c. so if you put a smaller cc gsr head back on it should raise compression. but if the b16 head was milled it could be close to a unmilled b18 head. youll have to measure the cc's to know for sure
you might be able to get a custom head gasket made to lower the compression. if you need to go lower. but it wont lower it much
on pump 93 gas you could run water/meth to raise the octane. because standard gas can only compress so much before it ignites itself. so the higher compression the harder to safley tune on a lower octane. so if you raise the octane you will have a safer tune. you want to stay away from pre detination.
i would look into e85 or water/meth injection if you want to boost a high compression motor.
theres guys out there running 12to1 on 6psi from jrsc kit. on pump gas no meth. it can be done. a motor with higher compression will make more power on same boost then a lower compression motor. so 12to1 with 6psi is like 10to1 on 8-9psi. so thats less strain on s/c with cooler air. because the more psi on roots s/c the more heat.
you could always sell the built motor and buy a oem motor to boost. or throw new pistons in there to lower the compression if you dont want water/meth and tuner says compression is too high for pump gas. but water/meth is simple to install and helps a bunch. cheaper mpg too. you could run %100 water or %100 meth but most choose 50/50 or 70/30