WTF is this?

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Some new & wierd type of snake oil I am guessing. Anyone seen this one before?

Reply to
Mal Osborne
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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.

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Reply to
John McGaw

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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

Reply to
pws

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.

Reply to
Lanny Chambers

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

Reply to
pws

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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

Reply to
Leon van Dommelen

rammm@REMOVE_THIS_TAGdommelen.net (Leon van Dommelen) wrote in news: snipped-for-privacy@4ax.com:

True, but:

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.

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 here:

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.

Reply to
XS11E

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

Reply to
Leon van Dommelen

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

Reply to
Mal Osborne

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.

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Reply to
Mal Osborne

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

Reply to
Bob Boswell

I agree 100%. The guys who design engines at Mazda (and even at Ford) aren't stupid.

Reply to
Grant Edwards

The amount of fuel delivered is dependent on the length of time the injector stays open AND the pressure in the fuel rail.

That's true ONLY if there is sufficient pressure. Apparently the Euro spec may not have sufficient pressure so even though the injector is held open the maximum length of time, insufficient fuel is delivered and that's a reason for an adjustable regulator..

And the literature about the adjustable regulator addresses that situation, apparently the Euro spec M5s don't deliver sufficient fuel under sudden acceleration, causing a "stumble" which more pressure can cure.

All that is unimportant to US owners, the only advantage of the device here might be lower cost for a replacement but that's hypothetical as well since it's not sold by Moss here in the US.

Oh, BTW, I'm wondering if the adjustable regulator might be a way of getting around some regulations that prevent changing the programming of the ECU? Anyone know?

Reply to
XS11E

"Mal Osborne" wrote in message news: snipped-for-privacy@quokka.wn.com.au...

My guess is that it's not needed. From the website

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electric fuel pump supplies fuel at a high pressure to the fuel rail andinjectors, which is then regulated by a fuel pressure control valve.Typically, the regulator is not adjustable and is pre-set to a 3 bar maximumpressure. At idle the fuel pressure valve reduces it by 0.5 barapproximately to 2.5 bar. When accelerating quickly from standstill thefuel pressure increases at a proportional rate retaining a lean fuel mixturestrength as required by the E.E.C. for new vehicles. However, the resultanteffects of the standard valve produce lethargic throttle response,occasional drivability problems at slow traffic speeds, intermediateperformance 'flat spots' when acceleratingBy comparison Ref: Power Boost Valve (replacement)Firstly, this valve has an adjustable fuel pressure, effected by themovement of an adjustment screw on the crown of the unit.New Power Boost Valves are pre-set with a maximum fuel pressure of 2.5, 3.0or 3.5 bar, depending on the vehicle in question, and similarly (to theoriginal valve) the fuel pressure is reduced by 0.5 bar approximately atidle. There the similarities end.On acceleration from standstill the Power Boost Valve fuel pressure willincrease at 1.7 times the standard rate. This will produce a healthy,strong fuel mixture strength which will instantly improve the drivability ofyour vehicle, providing instant throttle response removal of performanceflat spots faster acceleration extra engine performance The regulator enhances engine performance on acceleration by enriching the mixture strength. On constant throttle and cruise conditions the valve returns to a normal regulator function. The Power Boost Valve is simple to install and in most instances basic fitting instructions are provided. These units are mechanical and are considered maintenance free. =============================================================================== The US spec Miata (at least the 1600) doesn't seem to me to have these problems and, if anything, may even run a bit rich. There must be differences between EPA and EEC regulations.

Reply to
XS11E

Incredible claims require incredible proof. Do you have hard evidence that Mazda produces Miatas with insufficient fuel pressure? And why this would require an adjustable fuel pressure controller?

And no, the advertising, what you call "literature" for this device, does not count.

Leon

Reply to
Leon van Dommelen

rammm@REMOVE_THIS_TAGdommelen.net (Leon van Dommelen) wrote in news: snipped-for-privacy@4ax.com:

There's no incredible claim made, only that an adjustable regulator can solve problems that result from insufficient pressure.

Sure, the fact that the product exists. If there were no problem, they wouldn't have a fix for it.

Ask Moss Motors about it, see how many they sell. FWIW, I've had to use adjustable pressure regulators on a couple of engines but in each case it's been to reduce pressure, not increase it.

Reply to
XS11E

Just like the "tornado" vortex inducers? And the cow magnets that "align the gasoline molecules"? And those 7" diameter exhause tips?

People buying something doesn't prove it's useful.

Reply to
Grant Edwards

Grant, you beat me to the punch. When I read XS11e's comment I immediately thought of the "vortex inducers" and fuel line magnets.

Again, why has there not been a single comment here by even one European Miata owner on this low fuel-pressure problem pressure that supposedly exists and how they fixed it with this power boost valve?

If usefulness were a requirement for a product, most of our our retail stores wouldn't have half of the things on the shelves that they do, and since when did snake oil become useful in any way for anyone but the seller?

Pat

Reply to
pws

You mean, to anyone other than snakes?

Iva & Belle.) '90B Classic Red.) #3 winkin' Miata

Reply to
Iva

Well, I guess the placebo affect is both real and useful. Snake oil really does make some people feel better. :)

Reply to
Grant Edwards

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