Dodgy Claims - and stuff you shouldn't attach to your engine The Automotive Room 101 Words: Rob Bell Acknowledgements: Everyone who keeps emailing with yet more contenders for this section!!! Thank you all!

Isn't eBay a wonderful invention? It's full of useful car parts, knick-knacks and general 'stuff' that you can spend hours salivating over, and heck, some of them are genuine bargains. We all use it all the time, and would not be with out it.

But not everything on eBay is gold dust. Some of the wonder gadgets sold on eBay (and this isn't eBay's fault) are nothing more than automotive snake-oil: parts that can't possibly offer what their sellers say that do. And when it comes to cars and engine tuning, there is a particularly rich seam of dodgy stuff that frankly shouldn't be touched with a barge pole.

As this is one of those 'frequently asked questions' - I thought that it would be worth while looking at some of these 'once in a life time offers' that should be avoided on your MG... (names and items numbers obscured to protect the guilty - although why I should bother doing this I don't know... well, other than legal reasons that is)

So, if you are sitting comfortably, have your pop corn to hand, let's go through just a few of the classic duff products to ever disgrace an engine...

I would have to rate this class of product as the number one cheesy cheap "performance mod" on the internet - which is pretty impressive given the level of competition. A typical eBay advert will probably look something like the one opposite (click to enlarge).

On the face of it, this looks wonderful doesn't it? For a 'Buy it now' price of just 4 quid, you can add up to 20 bhp to the performance of your engine. Fantastic - we must all go and buy one now! Err, no we shouldn't.

It looks too good to be true - and of course it is. Even the best replacement engine management chips on a normally aspirated 16 valve 4 cylinder engine can liberate no more than 3-5bhp, so the 20 bhp claim is looking shaky before we even start to look at what we're being offered here. So what are we being offered? Some eBay sellers are disarmingly honest in their description of this product. It is a resistor. A simple resistor - and possibly a couple of wires, potentially encased in a small plastic box. You could probably buy a box of resistors for a few pence from your favourite electrical retailer, so even the knock down price of 4 quid is starting to look a little steep.

So how does it work? As some eBay sellers will tell you, it works by adding resistance to the inlet temperature sensor signal. The inlet temperature sensor works by varying its resistance value with temperature: as it gets warmer, the resistance across the sensor drops. By putting another resistor in series with the sensor, in effect, you are fooling the electronic engine control unit (ECU) into thinking that the inlet temperature is a good deal cooler than it is. As cooler air is denser than hot air, the ECU puts more fuel into the cylinders to make use of the greater oxygen content, and if the air is indeed cool, the net result is more power. Cool air in is such a good idea that on forced induction engines, much effort is expended in dropping the inlet temperature using charge coolers/ intercoolers. But that's another discussion. If the air isn't as cool as the engine management 'thinks' it is, you'll be pumping more fuel into the cylinders unnecessarily. Effectively, you are doing the same as fitting a up-rated fuel pressure regulator - and the net effect is the same: either no extra power or indeed worse: a LOSS of power as air and therefore oxygen is displaced in preference to an increased volume of fuel. And long term, this extra fuel causes bore wash - a process whereby the petrol washes away the lubricating oil from the cylinder bore causing markedly increased wear.

The paradox of these things is that often the engine can feel stronger - in much the same way that I found that the up-rated fuel pressure regulator made the engine feel stronger at low rpm (read more here). As a result, many people are sucked into this ruse and believe the hype, and unless you've got before and after rolling road runs on a reliable and honest rolling road, then truthfully, you'll be none the wiser. But some eBay traders will try and fox you with rolling road data of their own to support their amazing claims. Don't be fooled. I include one such 'power curve' for your amazement (or amusement?). Although the y-axis is labelled as 'BHP', in fact this is a torque curve (which you can tell by the shape - a power curve is typically a line that rises at around 45 degrees from the axis origin, depending on how the axis are scaled and how much power is being generated - there are plenty of power curves on this site for you to compare this one with). This kind of presentation doesn't fill one with confidence - but even if a 'before and after' POWER curve is presented, you have to use a healthy level of scepticism when interpreting this kind of data. In this case, a resistor is unlikely to make any difference whatsoever.

In conclusion, save your 4 quid and save your engine - and buy something more worthwhile instead. Which wouldn't be any of the following candidates...

Here's a recent development that I've only just come across - a modification that is not the "Resistor Chip" - but a modification that has very similar claims laid upon it. Apparently, what this particular chip does is to modify the oxygen signal from the exhaust Lambda probe. The Lambda is particularly useful in constant state running where it is used to determine whether the car is running lean or rich - and as such provides information on the stoichiometry of the fuel mixture. Many cars will run a slightly lean mixture, as this is the way to better economy and emissions - so there can a little bit of room to play with with these particular settings. But not, sadly, 20 bhp worth on a 1.8 litre 4-cylinder 16v engine...

While it is true that this isn't the 'resister modification', it is in fact striving to do something extremely similar: cause the engine management to over-fuel for a given set of circumstances. Assuming that you can be clever about this, you might eek out perhaps 1 or 2 bhp on a 16 valve normally aspirated engine. But there isn't a great deal of give - and therefore plenty of opportunity of getting the settings hopelessly and uselessly out of the range of benefit. And there is the risk of over-fuelling that is ever-present in the 'resistor chip' modification too. Which means bore-wash and excessive engine wear if things aren't set up as properly as they should be.

And there may be another problem on an engine managed by MEMS, MG Rover's management chip: the Lambda is broadly only used on closed-loop running - which is to say constant throttle openings where fuelling and ignition is largely determined by the Lambda. Under full throttle openings, the fuelling is dictated by the fuel and ignition map... which actually means that Lambda is effectively ignored. So when you're cracking on, this modification won't be felt...

Actually this also means that it would be almost impossible to see a power increase on a rolling road - since these are performed with an open throttle, typically with third gear engaged. Which makes interpreting the rolling road curves (some rather striking animated power curves in the advert I saw) rather difficult to understand, and perhaps fire up the cynicism centres of the brain...

So yes, I think that this gets a well earned 5-star duff rating. I won't work under full throttle conditions, and under almost any other state threatens to over fuel the engine needlessly with those aforementioned risks to your engine's longevity. Not a product I'd put on my Christmas list, sorry.
 

I mentioned above that the resistor 'chip' had some serious competition to be the number one duff tuning product on the internet - and for sure this magnet thing runs it extremely close! So what is this piece of precision engineered magnetic genius supposed to do? According to some of the advertising bumf that comes with this type of product, "as gasoline sits in your gas tank, the molecules tend to clump together because of weak magnetic forces called Van der Waals forces. Clustered fuel molecules are broken apart as they pass through the strong magnetic field. This allows more of the molecules to be burned."

Hmm. Right. Like so many products of this type, there is an element of scientific truth behind the claims. For example, it is entirely possible to make polarised molecules, such as water, align in a magnetic field. In fact this is exactly how medical magnetic resonance imaging (MRI) body scanners work. By subjecting the human body to a strong magnetic field using a large, liquid nitrogen cooled superconducting electromagnet, it is possible to get all the water molecules to line up in the magnetic field like so many compass needles. Radiowaves are then used to push the water molecules out of this alignment, and when the radio wave is switched off, the water molecules snap back into alignment and emit a radio signal of their own, which the scanner picks up to build up an image of the inside of the body. Then an image in 2D 'slices' or even in 3D of the body can be created for analysis. And once the patient being scanned is removed from the scanner, all those water molecules go back into their random alignments as though nothing had happened...

Obviously MRI scanners have little to do with automotive engineering. That said, this example does highlight a number of problems with the magnet fuel line modification. Firstly, hydrocarbon molecules that make up fuel simply aren't all that polarised. Secondly, the fuel line magnet simply isn't all that powerful (certainly nothing like as powerful as a medical MRI scanner). And finally, as soon as the magnetic field is removed, the molecules return to a completely random alignment - and more than likely, even if fuel molecules could be 'marshalled' in the way shown in the figure opposite, left, they'd more than likely go back and "clump" together again as soon as they left the magnet...

So it seems extremely unlikely that this gadget would be able to do the things promised of it by its sellers. Interestingly, and with remarkable timing, those fantastic chaps from the Discovery Channel (Myth Busters) aired a programme testing this (and a number of other products) just days before I wrote this article. Comparing before and after modification results from a rolling road using both a car with carburettor or fuel injection, they sought to find out what happened when this product was fitted. Neither engine power nor fuel economy was altered at all on either vehicle. Their conclusion was therefore, it doesn't work!

So once again save your money - it may be cheap, but its useless. But at least unlike the resistor modification, it won't damage your engine.
 

Oh, this has so got to be a good contender for the top duff spot... The Hydrogen generator. It's brilliant apparently, because "the hydrogen generator uses principles of chemistry and physics to split water into its atomic components. Hydrogen and Oxygen. Your generator is refilled with regular water. All the instructions are included. It is a very simple operation device."

So it's using electrolysis eh? Cunning. This particular advert from a country that I'm not mentioning, but it is on the other side of the Atlantic, boarders on the comical - to the extent that I wondered whether this was a spoof? But apparently, there are opportunities to buy hydrogen generators, which surprised me. But for sure, one day there will be Hydrogen powered cars. BMW have recently released a 7-series that is dual fuel for hydrogen and petrol - so what is being offered here - at least in terms of burning hydrogen in a conventional car engine - is plausible.

However, one thing that you'll not find fitted to this BMW is one of these hydrogen generators... One wonders why?

Once again, those friendly chaps from the Discovery Channel's Myth Buster series came to the rescue. They recently tested one of these Hydrogen generator products. Unfortunately, nothing like enough hydrogen was generated to even start the engine, let alone run it...

However, it is possible that hydrogen could be produced to supplement conventional fuel - and perhaps this idea might have merit. But of course, you'll need to alter the fuel and ignition map to compensate for the altered fuel burn that adding hydrogen will have. And that's assuming that you have the expertise to install these gubbins into your car successfully, and to provide a constant fuel/hydrogen mix. There is more discussion on this type of product here - and it's worth a read; it is written by an automotive engineer.

A good buy for enhancing the performance and fuel economy? In this author's opinion, not really. This looks to be jumping on the Hydrogen fuel cell band wagon. I think that you can keep your plastic bucket, two large bolts, a pack of steel washers and some brightly-coloured tape - I'd save my money for other things, thanks.
 

Here's another classic example of engine-tuning 'snake oil' - the electric supercharger. The interesting thing is that the electric supercharger does exist, and they can and do work. But this particular one is not it. The 'real' electric supercharger compromises of no less than three 4kW DC electric motors turning an Eaton Supercharger; rather than running the Eaton in its normal mode, from the engine crank pulley (the electric motor powered supercharger is pictured below, left), the electric motors take up the strain.

You can read more about this awesome electric supercharger here - and one of the things that will strike you are the huge electrical demands this little beauty places upon the vehicle in which it is installed. Frankly, your MG's standard 12v electrical system is woefully inadequate.

So let us compare and contrast this 'real' electric supercharger with the 'electric supercharger' what we see on eBay, an example of which is pictured on the right. On observation, two things are immediately apparent: first is that the unit pictured on the right is remarkably compact if it is to have the boost properties claimed of it. Second is the size of the power cable. It is difficult to judge scale here - but compared to the thick trunks of cable fitted to each of the motors attached to the supercharger on the left, the eBay motor cables appear pretty feeble. Giving it the benefit of the doubt, this cable is probably rated at no more than 15 amps. And of course it is connected to the standard car's 12 volt electrical system - so the motor can be rated at no more than 180 watts - some way short of the three motors fitted to the Eaton on the left - which are EACH rated at 4000 watts.

So the eBay 'supercharger' is small, and uses a small electric motor. Apparently the impeller speed is rated at 25,000rpm. Sounds great - but in reality this is meaningless. Superchargers - to simplify things a lot - compress air. There is no way an open propeller will compress air, even if it is running fast. And remember too that a 1.8 litre engine, at tick over at 1000 rpm, working with a volumetric efficiency of 80% (K-series is actually over 90%), will be drawing in (1800/4 * 1000 * 0.8) 360,000 cubic centimetres of air per minute - that's 6 litres per second! Do you reckon a 180 watt computer cooling fan running at 25,000 rpm can shift over 6 litres of air per second? No, I don't think so either - and one has to wonder what this thing does to air flow when you give your engine some stick at the upper reaches of the rev range... Perhaps it works as a turbulence generator (see below)?

Interestingly, Daren Jackson tried one of these 'electric superchargers' way back in 1999 and put his MGF 1.8 VVC on the rolling road as an independent test. Admittedly it wasn't the one shown here, but it was very similar product but for the odd-looking purple valve thing shown in the picture on the right. Result? No power gain whatsoever. There was no torque advantage either. Perhaps we should be surprised that power was not limited by this thing in the inlet tract!

This modification deserves its 4.5 star duff rating. Avoid and save your money!
 

Wow - here's a product that claims to be more efficient than a turbocharger - and without even resorting to forced induction! Surely this has to be the best thing since sliced bread? According to its sellers, this is how it works: "The turbulence generator's airflow dynamic produces a swirling, fast-burn effect in the combustion chamber. This creates finer particles of atomized fuel, allowing better flame propagation and more complete combustion." I particularly liked this bit in the product description: "The turbulence generator is much less expensive and more efficient than any turbocharger, supercharger, blower, or intercooler. Its superior design increases horsepower while lowering fuel costs!"

Seriously cool stuff eh? More efficient than a turbocharger, a supercharger, blower or intercooler eh? Erm - I don't know what is meant by a 'blower', and an intercooler is only ever used with forced induction to cool the intake air, but putting that aside, how can a vortex generator (which this turbulence generating device would appear - and claims - to be) possibly improve on the greater than 100% volumetric efficiency achieved by forced induction? Clearly it can't. Perhaps we're talking about another sort of efficiency?

Yes, again, there is a grain of truth in the mechanism that this device is supposed to work. In the cylinder head, engine designers often go to some lengths to ensure that there is turbulent flow in the inlet port to ensure adequate fuel atomisation and mixing with air - which as is claimed above, does indeed lead to better flame propagation and more complete combustion in the combustion chamber.

Trouble is, this device is designed to be fitted in the inlet tract - well before the inlet manifold, let alone the inlet port of the cylinder head. And as the K-series engine as used in the MGF and TF uses multi-point fuel injection - with the injectors effectively spitting the fuel directly into the cylinder head's inlet port (and onto the back of inlet valve so as to have as short a distance between injector and combustion chamber as possible), having turbulence all the way back at the throttle body or air filter would really be pretty pointless. Chances are that any vortex/tubulence that this thing usefully generates will have gone by the time the intake airflow hits the inlet manifold...

You can read more about this device here - and it's related cousins, all of which are supposed to achieve the same thing. And as for the Ecotek - I am not going to say anything - but look at this webpage. Looks as though I am not the only one with a healthy level of scepticism!
 

Oil cooling - a very laudable aim on a car engine that is subject to heavy use - be that driving energetically on the road or motorway, or be that driving on the race track. Oil temperatures can soar on the mid-mounted K-series - particularly on tuned engines or even standard VVC engines. Multigrade synthetic oils can tolerate very high temperatures much better than earlier generations of engine oil - but exceed 140 degrees Celsius for prolonged periods of time and the oil WILL start to break down. So how about one of these finned 'oil coolers' that bolts onto your oil filter? Great big finned heat sinks work well on electrical hardware doesn't it? This kit is a socking great bit of metal with a even greater surface area and blimey it's even blue and anodized, so it must be good - so it must work must it not?

This is how to do it properly - an oil/air radiator with an absolutely massive surface area ideal for cooling overheating oil.

Perhaps it does - but its capacity will be extremely limited. Compared to a genuine automotive oil cooler - such as those manufactured by Mocal (example pictured opposite, left), the surface area offered by this 'bolt-on' oil filter heat sink for cooling is clearly extremely limited.

Cooling surface area of this bolt on blue-thing is not all that great compared to the real deal oil rad pictured on the left.

And there is an additional problem too. Remember that the MGF's engine is mounted in the middle of the car - and is in fact tucked up relatively high behind the passenger compartment bulkhead. The net result of this is that the oil filter is effectively well out of the way of the air stream - so the oil filter, sadly, is sitting in a stagnant pool of ever warming air. In contrast, on a front engined car, with the oil filter mounted on the front of the engine block (as it is on the K-series), the oil filter is much more likely to be in the path of moving air - and therefore far more likely to cooled than on a mid-engined car...

So unfortunately this product is a bit of a duffer too. It might offer a modicum of oil cooling if the oil filter is in the vehicle's air flow, but it's efficiency will be profoundly limited compared to a 'proper' oil cooling radiator. But on an MGF, it's an absolute non-starter. The only reason you'd fit one of these to your oil filter is because it looks nice. Oh dear - except you can't see the oil filter on an MGF unless you lie on the floor...

Recommended Reading:   Tony's Guide to fuel Saving