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OK, i no from a mate that they do wonders for a Pug 306 (the one under the GTI 6) he told me that we saves s**t loads on fuel with his...

Now, how much are they for a Polo GTi, where the fudge does it go and are they any good on the Polo’s???

all it is, is an adjustable fuel pressure regulator. I fail to see how on earth this can increase the power of your car. Only any use if you are running a highly tuned engine & the standard fuel pressure reg isn't supplying enough fuel causing the engine to run lean.

also, the only way I could see it saving fuel is to adjust it so it's not supplying enough fuel pressure to the injectors which is just daft & you're causing the engine to run lean which will not only make the car slower but highly likely to do some serious damage.

show me some before & after rolling road results of a car where one of these "power boost" (lol) valves has been fitted which shows an increase of power & I might change my mind.

until then I am firmly convinced that these are an overpriced placebo.

Well apparently it works kinder like this.....


When you use a standard fuel line its kinder like turning on a tap which puts the fuel into your engine. But when you use a power boost valve it makes it more like a tap with a shower end to it, spraying to fuel around more and so creating more surface area for the fuel to burn faster (kinder like burring a normal sheet of A4 paper compared to one that’s been shredded) and so increases the engines performance... now I’m not 100% on this, its only what I have been told

still not convinced. the job of the fuel pressure reg is to keep the fuel supplied at the end of the fuel rail at a constant pressure. it's not as if it's spraying the fuel into the engine, thats the job of the injectors where the spray pattern does matter.

The standard item is well up to the job. If it wasn't reacting quick enough & not supplying pressure when most needed (when you floor it) the car would misfire badly everytime you put your foot down. This is a possiblity on a highly tuned engine where it requires much more fuel more quickly than a standard engine & in this case an adjustable pressure reg. would be a necessity.

I'm not saying you are daft for even considering these things, I have looked at them before myself & read all the stuff the makers claim they'll do for you. But the more I thought about it the more I was convinced that their theory would only apply on an engine where the standard pressure reg isn't up to the job. You are best off saving your money.

Yep I tended to agree with you and again going on what my mate has said (and he’s no reason to lie tbh) it does improve your fuel consumption, or at least it did on his pug, now he has had some stuff done to that but not that much really, just an exhorts system and a induction kit I think, oh and a two stage clutch.

Cadey wrote:Well apparently it works kinder like this.....

When you use a standard fuel line its kinder like turning on a tap which puts the fuel into your engine. But when you use a power boost valve it makes it more like a tap with a shower end to it, spraying to fuel around more and so creating more surface area for the fuel to burn faster (kinder like burring a normal sheet of A4 paper compared to one that’s been shredded) and so increases the engines performance... now I’m not 100% on this, its only what I have been told

Oh Dear OH Dear - thats rubbish....

It is an adjustable regulator which replaces you OE fixed pressure reglator (normally they have 2 pressure settings a nominal and a slightly lower setting when a vacuum is appllied to reduce the pressure at idle) - the supposed advantage of a Power Boost Valve (PBV) is that it responds quicker between min and max and as a result reduces lag/reponse time and can also enable you to reduce/increase the line pressure supplied to the injectors. It goe between the pump and the injectors so can have no effect on the "shower end"

Every car I have ever worked on with a PBV fitted has been a pig to set up and performed worse than std - they normally end up going back to the owner with it in the boot and a std one re-fitted.....

What I would say in it's marginal defence is it's a bodge way of tweaking the fueling after increasing the air flow when the air flow is poorly measured and chipping the ECU isn't possible - but it is just that a bodge as whilst increasing fuel pressure will make the injectors flow more fuel it will be a linear increase accross the entire rev range - ie whilst it might be advantageous to have a 10% increase in fueling from 4000 rpm to 5500 rpm you cannot help but get a 10% increase in fueling from 1000 rpm - 5500rpm - so whilst improvements in performance are achieved the rest of the rev range suffers a decrease - Note thi can make a car feel faster or more "cammy" - it doesn't necessarily mean it is .....

PBV is no substitue for a proper re-mapping job where injector duration is increased exactly where it's needed and not as a broad brush stroke accross the entire rev range......

IHTH

Finaly a good answer to the PBV question

Chears dude...

Cadey wrote:Finaly a good answer to the PBV question

Chears dude...