Quote:
Originally Posted by mrkrad
Quote:
Originally Posted by alyabiev
Quote:
Originally Posted by mrkrad
Quote:
Originally Posted by alyabiev
Quote:
Originally Posted by mrkrad
Quote:
Originally Posted by Nugget
Quote:
Originally Posted by chenry
I typically do my best to run 91+E85 in my tank but when I don't have access I simply drop 91 in and go - the tune auto-adapts.
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Does this mean he is just relying on the DME to pull timing?
How does it "auto-adapt"? |
Quote:
Originally Posted by Nugget
Quote:
Originally Posted by chenry
I typically do my best to run 91+E85 in my tank but when I don't have access I simply drop 91 in and go - the tune auto-adapts.
|
Does this mean he is just relying on the DME to pull timing?
How does it "auto-adapt"? |
Knock sensors |
You do realize that if timing is retarded too much it can literally melt your exhaust valves, turbine wheel and cat? Of course there is EGT failsafe logic embedded, but this "adapting" concept is bs honestly. Knock sensor is not for "adapting" for fuel. It's there to make fast corrections POST knock, reducing cylinder pressure and temperature for a short time, not BEFORE knock events. |
It's adaptive with a map of load x rpm so if it detected knock it will remember and back off more and more timing until it is safe why if you run 87 on a b58 it doesn't require a new motor... bmw safeguards you from bad gas or think heatsoak sitting in traffic with the AC blasting you can't run the same timing in 120f weather stuck in traffic as you can when it's 30f outside even on 93 octane.. the knock sensors are a closed loop design to protect your motor always! |
Did you read the first part of my post? Retarded timing shifts mixture burn process further from actual cylinder space to exhaust valves, manifold, turbine wheel and cat. Absolute timing degree does not matter in that case. I.e. 4° at 7000 RPM is just as bad as -4° at 3000 RPM because burning takes time. |
Most motronic knock systems add fuel in addition to pulling timing when knock is detected! I don't think Bosch pulls boost or reduces desired load on hearing knock but anything's possible these days! |
Every kind of modern ECU (including Japanese) retards timing and richens up AFR and if knock is still present ECU would pull load target down A LOT - all the way to 110-50% range, which is observed as WGDC and TP values drop in logs. This is also known as "limp mode".