Power Boost Valve for only 20p ! !

[Dave Hester]

Not sure if this has been talked about before on the forum but this is a question that a few of you have probably heard of.

Firstly Im thinking about purchasing a pbv for the old williams, but Ive heard many people give totally different opinions about there usefulness and value for money and I suppose at the end of the day we all expect a few extra horses under the bonnet when we spend our hard earned cash on another bolt on goodie for our engine

Now I know what a pbv is (fuel pressure regulator) and what it does, but after recently talking to a mechanic, who works at our local rolling road and tuning garage , he told me that the pbv is a waste of money and you can gain exactly the same effect by putting a 20p jubilee clip on the fuel inlet pipe (not quite sure which pipe he meant whether it was the pipe going into the regulator or the one going out from that into the manifold) slightly squeezing the pipe and hence creating a greater pressure for the fuel to come out (the same effect when you squeeze the end of a hose pipe the water comes out faster!)

I know a couple of lads who have done exactly this on a 1.9 205 gti and an astra gte and they swear that it makes a difference, I didnt really beleive them at first but after being told by a proffesional rally mechanic that it works maybe there is some truth in it all!

Just wandered if any of you guys with valvers , willys or 172s have tryed or heard about this trick?

cheers

Jim

 

[Ben H]

Not heard of it mate, but I do have a PBV. Because the car came with it, I couldnt say how much difference it makes (if at all), but I think it helps cars with modified cams idle better.

Oh, and BTW, watch out when you play with fuel lines. One loose one and you might look like that poor girl in a recent "for those who drink and drive" off topic post.

 

[BenR]

A power boost valve........yes a regualtor, but a rising rate one.

Uses manifold vacuum, imreasing vacuum, decresaing pressure. No point really....so all it means is at full throttle presure increases andso more fuel is flowed per injector event.....just the same as a std regualtor, but with the ability to set the basse pressure.

The jublee thing sounds odd...as yes, it cna increase line pressure, but after that restriction pressure will return to normal. Also, restricting flow aint good, you could be supplying less fuel than the engine really wants.

Does your engine need more fuel?

And if it does, a little cheat is to take the std regulator and squeeze it ina vice, lightly bend the body so the spring pressure is higher this a higher baseline fuel pressure....easy peasy.

 

[Leigh]

After fitting a pbv on the williams, i did notice better response on acceleration. It took a bit of fiddling to get it set up right. But yer id saw it was worth the money. But there again i bought it on the cheap. So for my investment it was worth it. Now that i have cams as well id saw that it was very helpful with those.

 

[PaulRobo]

I have heard of people restricting the fuel return pipe, but not the inlet pipe.

 

[Dave Hester]

Cheers peeps!

 

[Dave Hester]

cheers peeps

 

[Nick Read]

PBV on its own isnt a lot of use, you dont really need to alter the fuel pressure unless you can get more air in to match and youre getting so much air that the ECU is running the injectors fully open to compensate. An unlikely thing really. Once you get busy on other mods like head and cams, a PBV is needed to dial everything perfectly but otherwise you wont see a lot of gains. The jubilee clip sounds a bit of a wacko idea. Restricting the fuel line will only create higher pressure up to that point. If you must restrict anything to increase fuel rail pressure, youd want to do it to the fuel return line back to the tank.

 

[Scooby Doo]

I had one on my 16valver, and along with a few other mods, it did make a difference, but beware of mechanics with itchy fingers! Mine was fine until I had a service in a different garage, when the fuel consumption went up drastically, resulting in me failing my emmissions on MOT day. I took it to Dartford Tuning, and he said someone had been fiddling wih the nut on the top, which was fine when I took it there before, but he said it had been turned right round - not something Id do, so it seemed the only thing that could have happened, he turned it back & put a mark on it for me just in case it happened again, and I had no problems passing the MOT the next day. So if you do put one on, make sure you set it properly, then mark it just in case!

(whoever brought my car got a lot of goodies for not a lot of money!!!)