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15-03-11, 12:41 PM
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#1 |
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Member
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Join Date: Jul 2003
Location: Doncaster, oop norf
Posts: 2,122
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Why do modern diesel cars have so little engine braking?
We have a few pool cars at work and they all go for miles when you take your toe off the throttle, why is that? My pickup has a CRTD engine and, a bit like the SV, "half" the time you don't need the brakes.
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15-03-11, 12:43 PM
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#2 |
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Member
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Join Date: Apr 2007
Posts: 3,770
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Re: Why do modern diesel cars have so little engine braking?
Because engine braking is uneconomical.
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15-03-11, 12:52 PM
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#3 |
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Member
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Join Date: Feb 2008
Location: Riding, North
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Re: Why do modern diesel cars have so little engine braking?
At about 1000rpm the fuel meter will bleed into the system so the revs will not drop any lower?
Since air is free to enter the cylinders pumping losses are a lot lower than petrol engines.
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Was: K2 naked in rapid yellow  - gone to a better? placeNow: Street Triple R |
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15-03-11, 12:57 PM
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#4 | |
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Member
Join Date: Jul 2010
Location: Devon
Posts: 876
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Re: Why do modern diesel cars have so little engine braking?
Quote:
 A common rail engine will work just like an injected petrol on over-run conditions; fuel will be completely cut until a certain rev limit is reached.The very high final drives used for economy, combined with heavy dual mass flywheels significantly lower engine braking effort. |
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15-03-11, 02:27 PM
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#5 |
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Guest
Posts: n/a
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Re: Why do modern diesel cars have so little engine braking?
I've found too that my little diesel will coast for fecking ages. It's as if there's barely any engine braking what so ever!
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15-03-11, 03:23 PM
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#6 |
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Guest
Posts: n/a
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Re: Why do modern diesel cars have so little engine braking?
Lighter fly wheel?
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15-03-11, 05:44 PM
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#7 |
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Member
Join Date: Jul 2010
Location: Devon
Posts: 876
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Re: Why do modern diesel cars have so little engine braking?
Heavier flywheel = more resistant to changes in speed.
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16-03-11, 02:51 PM
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#8 |
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Member
Mega Poster
Join Date: Jul 2003
Location: Doncaster, oop norf
Posts: 2,122
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Re: Why do modern diesel cars have so little engine braking?
Okay perhaps I phrased the question wrongly. Why does my pickup have masses of engine braking when a car doesn't? Does the engine do something differently?
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17-03-11, 09:31 AM
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#9 | |
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Member
Join Date: Jul 2010
Location: Devon
Posts: 876
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Re: Why do modern diesel cars have so little engine braking?
Quote:
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