high compression e85 turbo bp?
04-17-2013, 06:42 PM
#142
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dingdingding. The only empirical evidence I have is of one guy (eliminator77) who said that he did 9.5:1 and regretted not going higher. That's where I'm basing my 10.5:1 starting point for my E85 shortblock on.
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04-19-2013, 07:12 AM
#145
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Ok, in a futile attempt to save this trainwreck, I have a question.
MBT (maximum brake torque) is achieved when maximum cylinder pressure is reached at a certain point (about 15° ATDC). It is the most power you can make at a given compression.
There is mountains of data that shows a BP@8.6:1 will reach MBT on pump gas, and make more power than the same engine would at 9:1 because the 9:1 cannot reach MBT on pump gas.
Does anyone have any data on the highest compression that can be used while still reaching MBT on E85? 10.5:1 is good, but if you can reach MBT on 11:1 it will be better. Anyone found MBT@11:1 running E85?
MBT (maximum brake torque) is achieved when maximum cylinder pressure is reached at a certain point (about 15° ATDC). It is the most power you can make at a given compression.
There is mountains of data that shows a BP@8.6:1 will reach MBT on pump gas, and make more power than the same engine would at 9:1 because the 9:1 cannot reach MBT on pump gas.
Does anyone have any data on the highest compression that can be used while still reaching MBT on E85? 10.5:1 is good, but if you can reach MBT on 11:1 it will be better. Anyone found MBT@11:1 running E85?
Not the highest no. But with a milled head/block and Weisco "advertised 10.5:1" pistons resulting in a calculated static CR of 10.87:1; I was able to reach MBT running 17PSI boost from a Positive displacement supercharger and C-16 fuel.
I can tell you that with pump gas this thing would prob make less power than a JRSC'ed Miata with a RRFPR due to limited timing.
It amazes me that some people have such a hard time understanding the simplest of concepts. Timing makes MORE power than Compression (or boost) when you are limited by the detonation threshold of a particular fuel. If you are no longer living within the limits of that fuel you can make more power by increasing compression(and or boost) and timing.
Obvious troll it obvious. Stop feeding them
Here's the spark map
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04-22-2013, 08:42 AM
#146
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Holy **** how much timing you have 
With my 9.5:1 pistons I didn’t get any torque gains after 20-22deg. Here’s my E85 spark map
With my 9.5:1 pistons I didn’t get any torque gains after 20-22deg. Here’s my E85 spark map
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