Custom chip which avoids cold start rich mixture
03-10-2021, 01:16 PM
#1
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Custom chip which avoids cold start rich mixture
Hi guys,
It's a pleasure to write my 1st forum post.
I've read regarding bore scoring, that it might be caused by the rich mixture at cold start, which is mainly to light off the catalytic converters.
This rich mixture can wash the oil off the cylinder walls.
My thought was to get a custom chip that bypasses this cold start setting.
Will appreciate you hear your thoughts regarding this.
Thanks,
Nir
It's a pleasure to write my 1st forum post.
I've read regarding bore scoring, that it might be caused by the rich mixture at cold start, which is mainly to light off the catalytic converters.
This rich mixture can wash the oil off the cylinder walls.
My thought was to get a custom chip that bypasses this cold start setting.
Will appreciate you hear your thoughts regarding this.
Thanks,
Nir
03-10-2021, 04:02 PM
#2
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The fuel doesn't vaporize as easily in a cold engine therefore your effective AFR is higher. If you were to take our the initial rich running setting you may not be able to start the car or it will run rough.
03-10-2021, 04:37 PM
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The (Super) rich mixture at cold start main intends is to light off the catalytic converters.
This is why experts advise to immediately start driving so the car will warm up faster and the computer will stop the over-rich mixture.
So basically my idea is to have an AFR for a cold start, but without the catalytic converters considerations.
This is why experts advise to immediately start driving so the car will warm up faster and the computer will stop the over-rich mixture.
So basically my idea is to have an AFR for a cold start, but without the catalytic converters considerations.
03-12-2021, 04:16 AM
#4
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Location: Cairns, North Queensland, Australia
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991.1s with 9A1 engine have a lot more pop & crackle going on when throttle is closed compared to 997.2's.
This is enabled by an extra fuel squirt timed to flash off in the header, programmed into the ECU to add "Character".
So, on the 991.2s there is artificial enrichment of the mixture that is present every time the throttle is let off, which is a whole lot more time overall in this state, than just the cold start cycle.
I have an MT 997.2 that I can invoke real burble on a trailing throttle, I press the gas pedal almost imperceptibly, which i guess, is enough to send fuel, but not actuate the butterfly, but it sounds way cool!
This is enabled by an extra fuel squirt timed to flash off in the header, programmed into the ECU to add "Character".
So, on the 991.2s there is artificial enrichment of the mixture that is present every time the throttle is let off, which is a whole lot more time overall in this state, than just the cold start cycle.
I have an MT 997.2 that I can invoke real burble on a trailing throttle, I press the gas pedal almost imperceptibly, which i guess, is enough to send fuel, but not actuate the butterfly, but it sounds way cool!
