How much knock is enough?
Their isn't a given number where it becomes unsafe. In a rotary engine, by the time it knocks, its already too late. Basically, you need to find your usual knock readings to account for your cars "noise" which is different on every car. Its normal for your car to have high knock readings when not in boost. Once your in boost though, your knock readings should stabilize much lower.
thewird
thewird
Their isn't a given number where it becomes unsafe. In a rotary engine, by the time it knocks, its already too late. Basically, you need to find your usual knock readings to account for your cars "noise" which is different on every car. Its normal for your car to have high knock readings when not in boost. Once your in boost though, your knock readings should stabilize much lower.
thewird
thewird
Thread Starter
dominican boost junkie
Joined: May 2008
Posts: 325
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From: Dominican Republic
i am pushing 11 psi. I lived in the dominican Republic where pump gas is rated at 89 octane (Sometimes i can get 92 pump). When i pump the boost to 14psi i mixed it up with C-12 Vp racing gas
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You may want to look into a meth or water injection setup. It would be a good way to raise the octane level of your fuel.
Thread Starter
dominican boost junkie
Joined: May 2008
Posts: 325
Likes: 0
From: Dominican Republic
yes i have been thinking about the AEM meth-water injection, using 50% water and 50% methanol. But what about the knock reading. I am consistely getting a knock reading of 30-50 in my power fc with 11psi on 92 octane pump gas. When i use c-12 vp racing gas and pump to 14psi, my knock reading is about 30-50 also. i want to know what is the most knock that i can get safely on pump 92?. i wish to run maybe 12-13 psi on pump 92 and will be checking the knock reading.
Last edited by janrx7; Jan 7, 2009 at 12:30 PM. Reason: error
Joined: May 2004
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From: Home of the 305 Boyz(miami)
Well for the PFC you're almost SOL but..
on the other EMS units, you can run the car at a known-safe ign map for XYZ PSi (unless you've got real bad fuel, the car shouldn't pre-ignite at 10* @ 10PSi).
you can then view the knock sensor output at that point, make a note, then move up to 15 PSi on a safe ign map. From this point you could then recal your knock table to pull X-degrees of Ign out based on the knock sensor & your knock cal table.
things to consider is the age / wear on the knock sensor before paying it any real attention on safe Ign maps. once you've got the Knock-Calibration set, you could have the EMS yank out ign based on knock above X% of your knock cal table.. but since the PFC can't do this, you can at least set the ign map to something safe and see what the knock sensor reads out at those PSi levels.
...i'd like to see a firmware update or people move away from the powerfc.
there just isn't enough options for a single turbo user who doesn't really want to get too involved in his car/ecu.
on the other EMS units, you can run the car at a known-safe ign map for XYZ PSi (unless you've got real bad fuel, the car shouldn't pre-ignite at 10* @ 10PSi).
you can then view the knock sensor output at that point, make a note, then move up to 15 PSi on a safe ign map. From this point you could then recal your knock table to pull X-degrees of Ign out based on the knock sensor & your knock cal table.
things to consider is the age / wear on the knock sensor before paying it any real attention on safe Ign maps. once you've got the Knock-Calibration set, you could have the EMS yank out ign based on knock above X% of your knock cal table.. but since the PFC can't do this, you can at least set the ign map to something safe and see what the knock sensor reads out at those PSi levels.
...i'd like to see a firmware update or people move away from the powerfc.
there just isn't enough options for a single turbo user who doesn't really want to get too involved in his car/ecu.
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83revival
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Sep 3, 2015 10:42 PM