WTF is this?

Mal Osborne wrote:
> http://www.moss-europe.co.uk/MossUK/...=MX5_UMXV1221X
>
>
> Some new & wierd type of snake oil I am guessing. Anyone seen this one
> before?

Snake oil? Possibly. But as they say, "google is your friend": here is a
URL which purports to reveal the deep dark secrets of the device. You
can make up your own mind about the snakishness or oiliness of the
device from it or do your own search for "power boost valve" and see if
a different URL helps. http://www.fuelsystem.co.uk/pbv.htm

--
John McGaw
[Knoxville, TN, USA]
http://johnmcgaw.com

John McGaw wrote:
> Mal Osborne wrote:
>> http://www.moss-europe.co.uk/MossUK/...=MX5_UMXV1221X
>>
>>
>> Some new & wierd type of snake oil I am guessing. Anyone seen this one
>> before?
>
> Snake oil? Possibly. But as they say, "google is your friend": here is a
> URL which purports to reveal the deep dark secrets of the device. You
> can make up your own mind about the snakishness or oiliness of the
> device from it or do your own search for "power boost valve" and see if
> a different URL helps. http://www.fuelsystem.co.uk/pbv.htm

I am not assuming that you are promoting this device, but I do have some
general questions and remarks on it.

This is what it is supposed to help.

"lethargic throttle response"
"occasional drivability problems at slow traffic speeds"
"intermediate performance 'flat spots' when accelerating"

How can it be helping a problem that does not exist? Looks, smells &
tastes like snake oil to me.
My stock '96 miata ran fine, slow traffic, fast traffic, whatever. If
that device adds even 1/2 a hp I would be surprised.

This is what it is supposed to do.

"instant throttle response" - What does that even mean? If you are going
to get scientific, there is probably no such thing as true "instant
throttle response", but to my human perceptions, the car always took off
as soon as I hit the gas and let out the clutch, seemingly in an instant.

"removal of performance flat spots" - Flat spots? The car ran great the
entire time I drove it.

"faster acceleration" - Faster, I like that. That could be .0000000001%.

"extra engine performance" - Ha! Once again that figure can be anything
except a large number.
You can add forced induction to that 4 banger or nitrous, nothing else
is going to get much more performance out of that engine.

I would not order this power boost valve unless they include a Vortex
Valve with it. ;-)

Pat

In article >,
pws > wrote:

> This is what it is supposed to help.
>
> "lethargic throttle response"
> "occasional drivability problems at slow traffic speeds"
> "intermediate performance 'flat spots' when accelerating"
>
> How can it be helping a problem that does not exist?

The website implies that European-spec MX-5s use lower fuel pressure to
reduce emissions, and their injectors don't get all the fuel they're
programmed to squirt. That's the first I've heard of such a thing, and I
doubt it's true--U.S. emissions standards are more stringent, and our
Miatas tend to run rich as it is. Smells reptilian to me.

--
Lanny Chambers
'94C, St. Louis
http://www.hummingbirds.net/alignment.html

Lanny Chambers wrote:

> The website implies that European-spec MX-5s use lower fuel pressure to
> reduce emissions, and their injectors don't get all the fuel they're
> programmed to squirt. That's the first I've heard of such a thing, and I
> doubt it's true--U.S. emissions standards are more stringent, and our
> Miatas tend to run rich as it is. Smells reptilian to me.

I think of cars as German, American, Japanese, British, etc. I wouldn't
think to call one a European or an Asian car. Their term "European cars"
went right by me.
I think that your term of European-spec is a much better way to describe
what they are talking about.
Besides, don't different countries in Europe have different emissions
requirements?

My car has a high-flow fuel pump, the Vishnu fuel rail, 550cc injectors,
and it passes the tailpipe sensor emissions test with room to spare.
Is lowering the available fuel pressure ever the way that emissions are
reduced?

Anyway, since neither one of us has heard of this low fuel pressure
valve causing the car to drive poorly on European-spec Miatas, I think
that our suspicions are pretty well-founded.
We would have seen countless references about it by European Miata
drivers if this was true. Quite a few would have been looking to buy
U.S. or Japanese-spec valves for the last 16 years.
Strange that we haven't seen even one such comment or request. ;-)

Pat

John McGaw > wrote:

>Mal Osborne wrote:
>> http://www.moss-europe.co.uk/MossUK/...=MX5_UMXV1221X
>>
>>
>> Some new & wierd type of snake oil I am guessing. Anyone seen this one
>> before?
>
>Snake oil? Possibly. But as they say, "google is your friend": here is a
>URL which purports to reveal the deep dark secrets of the device. You
>can make up your own mind about the snakishness or oiliness of the
>device from it or do your own search for "power boost valve" and see if
>a different URL helps. http://www.fuelsystem.co.uk/pbv.htm

This page does not help. Not a single substantial claim is made.
However, while I am not at all an expert on modern engine control
or driver psychology, I might be able to offer a guess.

The engine does not control fuel flow primarily by the fuel
pressure, but by how long it keeps the fuel injectors open.
If this device is indeed capable of changing the fuel pressure
(i.e. there is a pump or variable reservoir inside, rather than
a less expensive void) the ECU will be fooled initially by the
fact that the fuel pressure is not what it was programmed to
expect, and performance will suffer a bit for a few strokes.
However, the ECU will quickly recognize the problem from the
O2 sensor and adjust the injector-open time. So, unless the
device lets the fuel pressure become low enough to cause
significant knock, the loss of performance caused by the device
will probably be negligible.

Unable to detect the loss of performance, the driver who has just
shelled out a lot of MSU to purchase the device and spent a
significant amount of cursing to install the device convinces
himself that performance *really* seems to be improved. Another
convert to write glowing testimonials on the web has been born.

Just a thought,
Leon
--
Leon van Dommelen Bess, the Miata Bozo, the Miata
http://www.dommelen.net/miata
The only thing better than a white Miata is two white Miatas

(Leon van Dommelen) wrote in
:

> The engine does not control fuel flow primarily by the fuel
> pressure, but by how long it keeps the fuel injectors open.

True, but:

> If this device is indeed capable of changing the fuel pressure

It is. It's nothing more than a fuel pressure regulator that replaces
the stock pressure regulator on many fuel injected cars. The
difference is that it's adjustable* and I don't know of any factory
regulators that can be adjusted.

> Unable to detect the loss of performance, the driver who has just
> shelled out a lot of MSU to purchase the device and spent a
> significant amount of cursing to install the device convinces
> himself that performance *really* seems to be improved. Another
> convert to write glowing testimonials on the web has been born.

Nah, if the car is running fine there will be absolutely NO change in
performance, if the car is running a bit rich you should be able to
slightly reduce the pressure and vice versa if it's running lean....

Remember your original statement that the amount of fuel (mixture) is
controlled by how long the injectors are open? That's right, so it
follows that a change in pressure will result in a change in the amount
of fuel delivered.

For a US spec Miata the pressure is correct (I notice Moss does not
sell this on their US website) so the only advantage of the device
might be if the original pressure regulator failed and this was cheaper
(they DO fail, I had to pay around $100 for a replacement on a Ford V6
some years back, I doubt they've gotten cheaper.

*If you're familiar with fuel pressure regulators, stop reading he

Simplified version of how a fuel pressure regulator works:

The fuel pump delivers pressure to the fuel rail that is higher than
can be used so the regulator provides a path from the fuel rail back to
the gas tank. It has a diaphragm operated valve that is controlled by
a spring so when the pressure exceeds the desired amount the pressure
overcomes the spring and allows extra pressure to bleed off back to the
fuel tank. An adjustable regulator has a screw adjustment that will
allow the spring tension to be increased or decreased. There is also a
vacuum fitting that will allow manifold vacuum into the diaphragm
chamber so that at idle or other times of high vacuum the pressure is
reduced as the vacuum works against the spring tension. This drops the
fuel pressure in the fuel rail when fuel demand is slight, hit the gas
and the vacuum drops and the pressure is increased again.

XS11E > wrote:

(Leon van Dommelen) wrote in
:
>
>> The engine does not control fuel flow primarily by the fuel
>> pressure, but by how long it keeps the fuel injectors open.
>
>True, but:
>
>> If this device is indeed capable of changing the fuel pressure
>
>It is. It's nothing more than a fuel pressure regulator that replaces
>the stock pressure regulator on many fuel injected cars. The
>difference is that it's adjustable* and I don't know of any factory
>regulators that can be adjusted.

There is no need for an adjustable fuel pressure regulator since
the injectors determine the fuel delivered.

>> Unable to detect the loss of performance, the driver who has just
>> shelled out a lot of MSU to purchase the device and spent a
>> significant amount of cursing to install the device convinces
>> himself that performance *really* seems to be improved. Another
>> convert to write glowing testimonials on the web has been born.
>
>Nah, if the car is running fine there will be absolutely NO change in
>performance, if the car is running a bit rich you should be able to
>slightly reduce the pressure and vice versa if it's running lean....
>
>Remember your original statement that the amount of fuel (mixture) is
>controlled by how long the injectors are open? That's right, so it
>follows that a change in pressure will result in a change in the amount
>of fuel delivered.

No. The injectors and O2 sensor *change* the amount of fuel to compensate
for differences in fuel pressure so that the same amount of fuel is delivered
*regardless* of fuel pressure. Higher fuel pressure -> shorter open time
-> same fuel delivered.

Possible cases where that would be untrue that I know of would be transient
situations, (hence loss of performance a few strokes) and some conditions,
like the Link ECU going in open mode when under significant boost. (You still
would program it to give the same amount of fuel, compensating for fuel
pressure anyway.)

If Mazda is fixing an emission problem in the UK by messing up the fuel pressure
so that the injectors cannot do their work properly, instead of reprogramming
the ejector-open time, that would seem to be extremely weird to me.

Leon

>For a US spec Miata the pressure is correct (I notice Moss does not
>sell this on their US website) so the only advantage of the device
>might be if the original pressure regulator failed and this was cheaper
>(they DO fail, I had to pay around $100 for a replacement on a Ford V6
>some years back, I doubt they've gotten cheaper.
>
>*If you're familiar with fuel pressure regulators, stop reading he
>
>Simplified version of how a fuel pressure regulator works:
>
>The fuel pump delivers pressure to the fuel rail that is higher than
>can be used so the regulator provides a path from the fuel rail back to
>the gas tank. It has a diaphragm operated valve that is controlled by
>a spring so when the pressure exceeds the desired amount the pressure
>overcomes the spring and allows extra pressure to bleed off back to the
>fuel tank. An adjustable regulator has a screw adjustment that will
>allow the spring tension to be increased or decreased. There is also a
>vacuum fitting that will allow manifold vacuum into the diaphragm
>chamber so that at idle or other times of high vacuum the pressure is
>reduced as the vacuum works against the spring tension. This drops the
>fuel pressure in the fuel rail when fuel demand is slight, hit the gas
>and the vacuum drops and the pressure is increased again.
>
>
--
Leon van Dommelen Bess, the Miata Bozo, the Miata
http://www.dommelen.net/miata
The only thing better than a white Miata is two white Miatas

> For a US spec Miata the pressure is correct (I notice Moss does not
> sell this on their US website)

Maybe some consumer or anti-polution laws in the "Land of the free" prevent
venders from selling this sort of stuff.

>
> The website implies that European-spec MX-5s use lower fuel pressure to
> reduce emissions, and their injectors don't get all the fuel they're
> programmed to squirt. That's the first I've heard of such a thing, and I
> doubt it's true--U.S. emissions standards are more stringent, and our
> Miatas tend to run rich as it is. Smells reptilian to me.
>

Anyone know which countries get more powerful Miatae? I remember reading
somewhere that the fiasco with overstated 2001 horsepower was due to
quoting the Japanese/Australian figures. The UK sold a detuned 1.6 version
well into the late 90s as well.

My '94 lacks a few features that might be mandatory in the USA, I have no
airbags, CEL, or clutch interlock. Mazda Australia also designed, built &
sold a heap of Miata SP' factory turbos.

http://carsguide.news.com.au/story/0...-26236,00.html

On Mon, 23 Oct 2006 19:48:51 +0800, "Mal Osborne" >
wrote:

>> For a US spec Miata the pressure is correct (I notice Moss does not
>> sell this on their US website)
>
>Maybe some consumer or anti-polution laws in the "Land of the free" prevent
>venders from selling this sort of stuff.

Not likely to be consumer laws surely, given the number of adverts on
US television for things to stick in the air intake to 'improve'
turbulance and disrupt the air flow?

If these things really worked, it seems likely that the makers - who
tend to have people who know how to use a dyno - would already have
fitted them.

just a though - yeah, only just though


Boz

PS some ^(*&^&^%(& scumbag thought it would be amusing to wrench the
drivers side mirror upward and damage the door panel on my MX-5 . It's
going to cost a fortune to put right.
I hope his willie goes black and drops off.. eventually