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Old 09-02-2011, 06:44 PM   #77 (permalink)
Arragonis
The PRC.
 
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Quote:
Originally Posted by Piwoslaw View Post
... After pulsing and throwing it into neutral, does it take its sweet time to get back to idle rpm?...
Yep - I think I posted this on your 307 thread - you notice this more when switching from Diesel to Petrol. The opposite is also true - people used to Petrol also notice the way Diesels die back to idle very quickly.

I think it is down to compression - diesel engines have higher CRs so they have more resistance even when no fuel is put in. They also have heavier flywheels but that is only meant to keep them going at idle.

For older engines I think they still had a heavier flywheel plus more internal friction - e.g. OHV vs OHC and different cam follower / bearing designs.

I do notice it the most when trying P&G - I go to the dizzy end of 6K+ rpm and it takes ages to drop down again.
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