Vacuum Advance Unit?

[madasahatter]

Well, that's what it looks like to me anyway.

Happened to pop the bonnet the other day, and in the middle of the 'V' there looks like a vacuum advance unit? It also looks like it should have a pipe connected to it, but this is missing. Should it be? (I cannot imagine how a vacuum advance would work without some sort of connection!!).

Presuming that there should be a pipe connected to it, where would I find the pipe to re-connect it?

Any pointers would be very gratefully received, because I am sure this will be effecting the cars performance as the revs rise!!

[mlumb]

no there should'nt be a pipe connected to it, i asked this question myself while at joospeed.

[grasp]

That will be the feul pressure regulator and the top of it where you think a pipe should go needs to be open to atmosphere.
hot tip change it to a boost pressure regulator,gives ya loads more power.........

[simond001]

How does that work, what does it cost, how much more power?

[GreenV8S]

quote:
That will be the feul pressure regulator and the top of it where you think a pipe should go needs to be open to atmosphere.
hot tip change it to a boost pressure regulator,gives ya loads more power.........

More fuel maybe, but why will that give you more power? Unless it was running lean originally?

[joospeed]

I've often wondered this when stuart posted it on the TVRCC forum. even with my high flowing 4.2 inlets we never have any weak mixture problems. If it's a quick easy route to more power it'd be worth knowing about .. any chance of posting some dyno printout scans stuart, before and after?

[grasp]

will do..........
Im taking a 4.5 to the rr early sept and will be fitting various toys-including a boost reg-will send you the stats from that......
the throtle response is 1.7 times quicker

>> Edited by grasp on Tuesday 20th August 22:46

[joospeed]

1.7 times quicker .. how on earth did you measure that?

[grasp]

I read the stats,graphs and the before and after fittment printouts of other cars before i bought the product-it appears to be true

[joospeed]

do you mean the presure regulator reacts 1.7 times quicker when it senses the manifold depression dissappear (as in the FSE advert)? .. surely that doesn't apply to the cerbie cos the regulator isn't connected to the inlet so there's no pressure communication to the regulator? I don't see how the regulator can make a difference unless the engine is running weak on accel enrichment as std... or do you connect it to the inlet and let the ecu trim the fuelling slightly richer to compensate for the drop in fuel pressure? .. then the engine would be running on an artificially rich fuelling trim when the lambda control is suspended on acceleration .. curiouser and curiouser cos the lambda trim is blended into the base map above 3.5k revs so above there it's make no difference any way unless you then increased the fuel baseline pressure - you can get rising rate pressure regulators so is this what you use. interested to know your findings on this stuart, sounds fascinating.