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Old 05-13-2019, 11:03 AM   #107
DarkSunrise
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Quote:
Originally Posted by Adam_L View Post
So the higher the compression ratio, the greater the effect down shifting becomes ? I never knew that, if that's indeed true.

I downshift, it just depends on the situation, but usually it's one gear at a time 6th to 5th , or 5th to 4th , 4th to 3rd. Sometimes I'll go 4th to 2nd gear, if I go from 40 mph…. down to 20mph fast ( brake, or engine braking + downshift). I'll say in the last few years, I've been doing more braking… then downshifting ( I'd rather replace brake pads, then to go thru a clutch faster) … but it depends on the situation.
Yeah my understanding was that engine braking was dependent on CR and multiplied through the gearing. But your comment got me thinking about the CR part and whether that's true. Turns out when the engine is off-throttle, it does slow the engine in the compression stroke, but returns most of that energy in the power stroke (essentially like a spring that's being compressed and released). So CR may not have as big of an impact if any on engine braking as I thought.

Some interesting discussion here:

https://www.carthrottle.com/post/the...ngine-braking/
https://www.lfs.net/forum/thread/582...t-really-works
https://jalopnik.com/actually-engine...ine-1818491096
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