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Fuel Pressure reegulator
phoenix70 - 5/11/08 at 09:45 PM

Hi Guys,

Just pulling my car to pieces to fit ITB and Megasquirt. Pulling off the regulator it just clicked, there is no plenum on ITB so vacumn pressure for the reg. Am I missing something, or do I need a different type of Regulator.

Or alternatively do I need to feed this from the vacumn pipes on the ITB before feeding it to the MAP sensor.

Cheers

Scott


MikeRJ - 5/11/08 at 09:49 PM

It's possible to dispense with the regulator vacuum connection and simply correct for this within the fuelling maps.

The downside is that have a vacuum connection effectively extends the dynamic range of the injectors, without it you need smaller pulse widths under light engine load which could cause problems if you are using big injectors.


matt_claydon - 6/11/08 at 08:05 AM

You need to tee all the vacuum connections on the ITBs and connect to the reg. You can share this with the MAP sensor on the MS. Some ITBs have two vac connections per body and you can therefore use one set for the reg and one set for the MAP sensor.

As above, you can do without but it's better practice to use the vac on the reg. You wouldn't be able to properly use Alpha-N fuelling without a vacuum-corrected regulator either which you may well want to do with ITBs.


MikeRJ - 7/11/08 at 09:57 PM

quote:
Originally posted by matt_claydon
As above, you can do without but it's better practice to use the vac on the reg. You wouldn't be able to properly use Alpha-N fuelling without a vacuum-corrected regulator either which you may well want to do with ITBs.


Pretty much every engine on throttle bodies I have seen used in motorsport has used Alpha N without a regulator connection. You can still compensate for the variation in fuel pressure through the map, but normal Alpha-N issues apply (e.g. calibration moving with age/wear).