Power Boost Valve

tux2006 · Post by **tux2006** » Sat Mar 10, 2007 9:53 pm

Would this actually make any difference to performance?

http://cgi.ebay.co.uk/PEUGEOT-406-1-8i- ... dZViewItem

Or will it just increase the fuel pressure? make the car run richer?

I'm quite seceptical of things like this what do you guys think?

jameslxdt · Post by **jameslxdt** » Sat Mar 10, 2007 10:40 pm

this will just make the car run like crap and ruin your cat, for optimum power your engine will need to run slightly rich, hence why it ignores the oxygen sensor as you need a mixture of about 14 to 1 for peak power but for optimum fuel economy and clean emissions you need a mixture of 14.7 to 1, so when you are at idle, part load or cruising the oxygen sensor will maintain a mixture of 14.7 to 1, but this 'do nothing valve' will make it more like 13.9 when the oxygen sensor is working and will most likely log a fault like oxygen sensor signal to low, or long term fuel trim lower limit at idle, and it will go into limp mode, and when at full throttle the mixture will just be so rich you will most likely loose power
if the peugeot could have got more power by raising the fuel pressure dont you think they would have?

tux2006 · Post by **tux2006** » Sat Mar 10, 2007 10:47 pm

cheers ye like you said I didn't think this would be any good like the usual crap that promises better performance thats why I was seceptical wouldn't have bought it anyway I'm too skint have £30 to my name

I had never seen one before didn't know what it did

lol

jameslxdt · Post by **jameslxdt** » Sat Mar 10, 2007 10:51 pm

£30, more than ive got at the moment, to be honest though the best way to get power out of the 16v xu engines is the gti6 bits, ive still got mine for sale

but they also sell on ebay quite often, and you wont sacrifice reliability as they are oem parts

niz406 · Post by **niz406** » Sat Mar 10, 2007 10:55 pm

jameslxdt wrote:if the peugeot could have got more power by raising the fuel pressure dont you think they would have?

No.... because of warranties!

A rising rate fuel pressure regulator is actually a good idea / device... it provides 1.7 x greater fuel pressure under load, leaving your standard fuel characteristics untouched... when load is applied to the engine, and vaccume acts upon the diaphram the presssure rate is increased.. as wide band O2 sensors are not included in cars, no faults could be raised as the sensor is reduntant higher in the rev range...

The harder you accelerate / drive the car, the quicker the valve responds..... if you don't abuse it, theres no use for it !

If you want to spend some of your hard earned cash on something.... then might I suggest stiffer lowering springs... about 35mm all round... believe it or not this can make a difference in acceleration.... is all to do with kinetic energy, there is lots wasted during gear change and weight shifting.... stiffer suspension will reduce this and increase constant velocity.... plus you will notice that it goes round corners so much better and quicker...... you'll be able to corner quicker, more quicker than an FSE PBV on stock suspension !

jameslxdt · Post by **jameslxdt** » Sat Mar 10, 2007 11:01 pm

yes but when the fuel pressure will still be too high when the o2 sensor is working, and can only switch so far and will eventually flag a fault as it can no longer get it to run at 14.7 to 1, in my opinion you will gain nothing from raising the fuel pressure except problems, if you think about it will also cause premature wear of the fuel pump as it will be working so hard to maintain that fuel pressure

tux2006 · Post by **tux2006** » Sat Mar 10, 2007 11:09 pm

I would take them off your hands if I had spare cash and I could fit them but I think I'd find it hard without the proper tools and never having really worked on piston engines before

I don't like fiddling with my own cars engine parts afraid of fookin it up...I'll happily have a go at someone elses though:cheesy: guess I just don't wana put myself up sh*t creek without an engine
If I leave it alone it might be crap but it works

niz406 · Post by **niz406** » Sat Mar 10, 2007 11:28 pm

jameslxdt wrote:if you think about it will also cause premature wear of the fuel pump as it will be working so hard to maintain that fuel pressure

The fuel pump pressure of a 406 is like.... 4 bar max so it has no bearing on the pump as the PBV comes pre set @ 2.5 or 3.0 bar depending on engine type.... NA / Turbo... don't forget that its the pressure regulator that regulates fuel rail pressure, and the standard units are rising rate types... they are just not adjustable... and thats what the FSE gives users, the option of adjusting...

Now with proper breathing mods and the FSE, it would be worthwhile don't you agree?

jameslxdt · Post by **jameslxdt** » Sat Mar 10, 2007 11:34 pm

you would still need a remap as well though as injection duration will be all wrong for the raised fuel pressure as the ecu has no idea of what the fuel pressure is, and the ignition timing will also need to be advanced to compensate, so in the long run, in my opinion i dont see there being any great gain

niz406 · Post by **niz406** » Sat Mar 10, 2007 11:41 pm

jameslxdt wrote:in my opinion i dont see there being any great gain

There isn't unless its flat out....

turbolag · Post by **turbolag** » Tue Mar 13, 2007 10:39 pm

Don't spunk loads of cash on these adjustable fuel pressure regulators. Ignoring the dubious benefits on an otherwise near stock motor, a Ford CVH injection FPR unit is fully adjustable and doesn't cost a lot new, and only pennies from the scrappie.

Personally, I don't hold with the "if it's so good, why didn't pug do it" school of thought. Economics, is the simple answer - a twin turbo V6 is undoubtedly very fast, and a possible (if unlikely, and fiddly!) modification, but pug obviously doubted they could sell enough to make such a variant worthwhile.

for example, the V6 HDi unit was being developed as long ago as the last decade, so why would pug waste time creating a high output 4 pot burner whne they new a 6 banger was in the offing? Only now are they filling the gap with twin blower 4 bangers.

I say, if you want to mod, then go for it, but just consider the possible implications for longevity and economy when weighing up the odds...and remember that one of the many parameters that a remap will alter is the fuel pressure!