This month in surgery

[PukkaSilvia]

Originally Posted by 30psi

I don't know what fuel pressure its running to be honest. Coz its a rising rate regulator and I have low vacuum, its prob wouldn't tell me much to take a base pressure reading.

Why would the fact you have low vacuum and it being a rising rate regulator not tell you much?. With an adjustable fuel pressure regulator you should set it up on a fuel pressure guage properly not guess it. You can use your boost guage to add or subtract your inlet pressure assistance to the regulator. Maybe im missing your point. explain? The reason being is you once said your cars std injectors were on there limits when it was on the rr at 17psi. by knowing your fuel pressure it may tell a bit more. A few extra psi on the fuel may make a few extra ponies if it allows that extra boost.

[30psi]

If the vacuum is lower the fuel pressure will be higher. You can't work back to work out what the pressure would be at correct vacuum as it isn't a linear adjustment on that regulator. Its 1.7:1, you could try to use that, but doubt it would be reliable info.

The regulator was adjusted on the rolling road. No more pressure can be added because it will overfuel at lower rpm/full load as the boost builds up. It overfuels at high rpm but half throttle as well.

On a boot from idle the a/f ratio goes rich up to 10:1 as the boost increases between 3-4k, then it settles down after that point.

If Ant wants to use an adjustabe regulator he should set it per the factory service manuals suggested fuel pressure, then take it to a good rolling road to see whats happening at different rpms and loads.

[PukkaSilvia]

Cheers for the info...ive just woke up so will try and get my head round what your saying later.

I understand how the regulator works etc.just not sure why You can't work back to work out what the pressure would be.....maybe once ive woke up.... cheers