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MG MGF Technical - Explain that again?

The power boost valve, how is it ment to work?

How I understand the marketing rubbish is:
The pump incresses pressure in the fuel line, it does this by replaceing the pump, incressed pressure is only added at WOT.


BUT
on the k-series the pressure is _not_ regulated by the pump, looking at the engine, inside the U shaped inlet manifold is the fuel rail, you can see it enter at the left and leave at the right, then it goes thru a widget and loops back under the manifold.

This widget is what regulates the pressure, you will note an extra pipe which goes into the manifold, this is to find the pressure of the air, so the fuel rail pressure changes dependant on the pressure in the inlet manifold to acheive a more equal flow from the injectors.

SO
How does this power boost valve work again?
Will Munns

Will,

You know my technical competence, so I don't know exactly how it works, but ...

You say replaces the pump - no, it replaces the fuel regulator. As I understand it the standard regulator is fixed pressure - somewhere between 2.8 and 3.2 bar. The FSE is of course adjustable. There is also meant to be some advantage to the FSE (over the standard regulator) when you accelerate hard.

I bought an FSE originally to potentially compensate for any leaness in the mixture after having the head ported. As it happened a rolling road run showed that the mixture was fine. However, Roger Parker told me that there was some benefit to throttle response and so I went ahead and had it fitted anyway. It does seem to sharpen the throttle.

HTH
Dave

So the FSE fits on the fuel rail (not near the pump)?
Will Munns

The main FSE is freestanding (attached somewhere to the bodywork) with three pipes running from it. One pipe goes to an adaptor piece that replaces the original fule regulator. The other pipe goes to the fuel rail (I think) and the third is not a fuel pipe but a pipe that replaces the manifold pipe for the air pressure measurement.

Sorry for not being more technically articulate, but I can send you some pics if you like. My FSE was fitted by Techspeed who have it look like a factory job - a real work of art!
Dave

Must learn to type better or read before I send.

"The main FSE is freestanding (attached somewhere to the bodywork) with three pipes running from it. One pipe goes to an adaptor piece that replaces the original fuel regulator. The other pipe goes to the fuel rail (I think) and the third is not a fuel pipe but a pipe that replaces the manifold pipe for the air pressure measurement.

Sorry for not being more technically articulate, but I can send you some pics if you like. My FSE was fitted by Techspeed who have made it look like a factory job - a real work of art"
Dave

Cheers, that explanation works better for me!
Will Munns

Just got an email from Matt to say that he's got a batch of re-rated "standard" fuel pressure regulators for 45 quid inc delivery. Have email contact details for anyone interested (they're rated at the top end of the standard range: 3.2-3.3bar).

:o)
Rob Bell

According to the hype, the FSE power boost valve doesn't just hold a higher fuel pressure, but also copes with changes in fuel pressure more rapidly.

Its this rate of change of pressure, where they get their claim of 1.7 times better than the standard regulator.

True or just hype?? dunno.

I had one fitted to sort out a problem with low fuel pressure, which it did.

paul weatherill

This thread was discussed on 15/09/2003

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