Discussion
ok why are we fitting the dump valves on our cars.... is it purelly the sound? as it has no bearing on protecting the turbo as the blades are too small to stall and snap the shaft (reson they were originally designed and have to be fitted to large boost huge turbo applications).... do people really perseve a reduction lag during the gearchanging?
The reason I wonder is that having looked at the Nobles piping it seems the turbos have a lot of pipes to represurise after all the boost has been lost and to me this would take longer than and potential respool of the turbo due to it slowing down..... I removed mine on a 1.8bar cossie and it reduced the lag even though it was comonly 'known' that you had to have them fitted!
pretty amazed that it effects MPG though.... may be that the ecu isnt set up for the change in gearchange spooling... but still cant really see how it could have an impact if the cars being driven the same, strange.
The reason I wonder is that having looked at the Nobles piping it seems the turbos have a lot of pipes to represurise after all the boost has been lost and to me this would take longer than and potential respool of the turbo due to it slowing down..... I removed mine on a 1.8bar cossie and it reduced the lag even though it was comonly 'known' that you had to have them fitted!
pretty amazed that it effects MPG though.... may be that the ecu isnt set up for the change in gearchange spooling... but still cant really see how it could have an impact if the cars being driven the same, strange.
gadgeroonie said:
if a car is fitted with a Mass Air Flow meter or MAF then when you change gear the air continues to pass through it and out the dump valve - so the ecu thinks air is passing through the engine and adds fuel
the noble uses a MAP sensor not a MAF sensor - so this does not happen
FYI, the Rossion engine management scheme will use a MAF.the noble uses a MAP sensor not a MAF sensor - so this does not happen
See pics here:
http://www.nobleforums.com/showthread.php?t=3859
Agree with others, though, that adding a BOV to a Noble cannot affect MPG.
JLSELAN said:
gadgeroonie said:
if a car is fitted with a Mass Air Flow meter or MAF then when you change gear the air continues to pass through it and out the dump valve - so the ecu thinks air is passing through the engine and adds fuel
the noble uses a MAP sensor not a MAF sensor - so this does not happen
FYI, the Rossion engine management scheme will use a MAF.the noble uses a MAP sensor not a MAF sensor - so this does not happen
See pics here:
http://www.nobleforums.com/showthread.php?t=3859
Agree with others, though, that adding a BOV to a Noble cannot affect MPG.
i like the idle control valve - our cars could do with one !
gadgeroonie said:
JLSELAN said:
gadgeroonie said:
if a car is fitted with a Mass Air Flow meter or MAF then when you change gear the air continues to pass through it and out the dump valve - so the ecu thinks air is passing through the engine and adds fuel
the noble uses a MAP sensor not a MAF sensor - so this does not happen
FYI, the Rossion engine management scheme will use a MAF.the noble uses a MAP sensor not a MAF sensor - so this does not happen
See pics here:
http://www.nobleforums.com/showthread.php?t=3859
Agree with others, though, that adding a BOV to a Noble cannot affect MPG.
i like the idle control valve - our cars could do with one !
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