LeeM
Member
Registered: 26th Sep 05
Location: Liverpool
User status: Offline
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quote:
Originally posted by Steve
i was waiting for someone to bring up timing advancment, thats all well and good but generally most engines are setup with the timing pretty much as much as it can go before pre ignition, as this is the most fuel efficient setup.
you can tweak it a bit but you wont get much if any
Pre ignition is when you get pockets of heated fuel and air ignitig under compression, nothin to do with ignition timing
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
User status: Offline
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and how do you think these pockets of heated fuel and air get there?
pre ignition pinking can definately be caused by too advanced timing, in this instance its caused by too lean a fuel mixture as a result
[Edited on 02-12-2010 by Steve]
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sand-eel
Member
Registered: 15th Mar 07
Location: carluke/braidwood--IRNBRULAND
User status: Offline
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advanced timing CAN cause pinking if the fuel octane isn't high enough.
Its because when you advance the timing the spark plugs spark before the piston reaches the top (normal anyway) but advancing sparks the plugs even sooner. This makes more pressure and heat, higher octane fuel can cope with the extra heat/pressure without pre-igniting, normal octane can't thats why you can pre-ignition/pinking.
mmmkay.
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Steve
Premium Member
Registered: 30th Mar 02
Location: Worcestershire Drives: Defender
User status: Offline
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yep thats why they recommend if you remap a turbo car and the weather is warm to use higher octane fuel, its generally less likely in colder weather
[Edited on 02-12-2010 by Steve]
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John
Member
Registered: 30th Jun 03
User status: Offline
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quote:
Originally posted by Toby
quote:
Originally posted by Scotty C
quote:
Originally posted by corsa_nation
quote:
Originally posted by Scotty C
So why don't manufactures do it as standard? Not only can they advertise the fact the engine produces more bhp, thus getting to 60mph quicker and it's better on fuel.
Maybe because the power they come out of the factory with is most suitable for the mechanical components of the car in question.
True, but a mapping it for another 20bhp - 30bhp for increased mpg wont hurt the internals
may hurt with insurance and threrfore leaving the car outside its target market hence the two CDTi vaux engines at 120bhp and 150bhp same enigne etc
There were only a few 16v 120's, the rest were all 8v, different engine.
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Chris
Premium Member
Registered: 21st Sep 99
User status: Offline
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The main thing is a factory map you can drive the car from the north pole to the equator, a remap will be written for the localised climate.
So dont be driving a chiped car to the north pole or the equator.
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