What do I do with the 4 vac lines that run from each throttle body? Where do they connect to?
They go to the MAP sensor
ITB'S do not use the MAP sensor they use the TPS, you do not need to connect them, they can be blanked off.
You can use the to balance the throttle bodies- did mine today with a set of motorbike vacuum gauges.
Otherwise leave them blanked off or connected together as they are. As long as they are not open and thus able to suck air in.
Thanks guys, will block them off. Cheers
quote:
Originally posted by big-vee-twin
ITB'S do not use the MAP sensor they use the TPS, you do not need to connect them, they can be blanked off.
MS only uses the MAP sensor to take an atmospheric pressure reading at initial start up to work out the start fuel load, then does not use the sensor after that, it can take the reading without being connected to the ITB's.
It depends whether you are running speed density or alpha-n,
Speed density uses the TPS
Alpha-N the MAP combined with IAT to calculate the volume of air.
Speed Density is generally reccomended for ITB's but, if you have a relliable smooth vacuum, good results can be achieved with Alpha-n.
quote:
Originally posted by r1_pete
It depends whether you are running speed density or alpha-n,
Speed density uses the TPS
Alpha-N the MAP combined with IAT to calculate the volume of air.
Speed Density is generally reccomended for ITB's but, if you have a relliable smooth vacuum, good results can be achieved with Alpha-n.
quote:
Originally posted by SPYDER
quote:
Originally posted by r1_pete
It depends whether you are running speed density or alpha-n,
Speed density uses the TPS
Alpha-N the MAP combined with IAT to calculate the volume of air.
Speed Density is generally reccomended for ITB's but, if you have a relliable smooth vacuum, good results can be achieved with Alpha-n.
You've got SD and Alpha-N the wrong way round.
SD uses the MAP sensor
Alpha-N uses the TPS
Hybrid Alpha-N or ITB mode use both.
Some people using Alpha-N still use the MAP sensor to give a more reliable trigger for acceleration enrichment, particularly if they suffer from a noisy TPS signal. It is also useful to trigger overrun fuel cutoff.
I am using Alpha_N but I still have the MAP sensor connected to Megasquirt. I find it useful when data logging as MAP gives an accurate indication of "effective wide open throttle".
I have found another use for the four small vac lines. I have them connected to a small solenoid valve that opens when the radiator fan cuts in. This counteracts the drop in revs that I used to get.
quote:
Originally posted by r1_pete
quote:
Originally posted by SPYDER
quote:
Originally posted by r1_pete
It depends whether you are running speed density or alpha-n,
Speed density uses the TPS
Alpha-N the MAP combined with IAT to calculate the volume of air.
Speed Density is generally reccomended for ITB's but, if you have a relliable smooth vacuum, good results can be achieved with Alpha-n.
You've got SD and Alpha-N the wrong way round.
SD uses the MAP sensor
Alpha-N uses the TPS
Hybrid Alpha-N or ITB mode use both.
Some people using Alpha-N still use the MAP sensor to give a more reliable trigger for acceleration enrichment, particularly if they suffer from a noisy TPS signal. It is also useful to trigger overrun fuel cutoff.
I am using Alpha_N but I still have the MAP sensor connected to Megasquirt. I find it useful when data logging as MAP gives an accurate indication of "effective wide open throttle".
I have found another use for the four small vac lines. I have them connected to a small solenoid valve that opens when the radiator fan cuts in. This counteracts the drop in revs that I used to get.
Oops yes you're quite right, thats what you get for playing on LCB during boring voice conferences.....