Diesel ECU modifiers.

[pre65]

I was reading the Pro-Bitz website and claims of how it's "gadget" works wonders with power, torque and economy.

I thought I might try one on the Volvo and/or the Renault van as for £99 it seems very good value for money.

Has anyone here any first hand experience of this product, or company ?

http://www.pro-bitz.com/eshop/index.php

[Stuart Dean]

Philip
I don't know this unit but I would urge you to be a bit suspicious.
Some of these wonder devices work by delivering extra fuel to the injection system.
An ECU usually supplies extra fuel on start up and this is reduced as the engine warms up.
Some of these units modify the signal from the ECU which controls this and sometimes the flashy looking case houses just one solitary resistor.
(not audio grade either!!!) which is sneakily hidden in epoxy.
It's quite possible you will get increased torque, acceleration etc but you might well get alarming quantities of black smoke.
S

[Paul Barker]

#i too think these things are the worst snake oil. Their claims would be the dream of any manufacturer who has far larger R and D departments to create this configuration if it is genuin. They haven't but some two bit marketing gangster has?

[pre65]

I understand your comments Stuart and Paul.

I have had "horses mouth" endorsements of similar devices that do "what it says on the box", and will give increased economy due to the reasons stated. But generally these devices cost more than £99

[al newall]

They make a device that can be fitted to over 1700 vehicles.
They are not going to manufacture over 1700 different versions of it are they.
So it must be something simple that can be tweaked to suit.
They say that it can be adjusted. So it sounds like the tweaking is left to the customer.

Is there a money back guarantee? I didn't see that bit.

[shane]

Might be better going for something like this:

http://www.remapscience.co.uk/our_prices.html

[Nick]

Yep, I can't see how anything thats a simple fit to many ECU's can be doing amyting other tthan something simple like overriding a sensor. Wonder what one, maybe the lambda sensor:

Tampering with or modifying the signal that the oxygen sensor sends to the engine computer can be detrimental to emissions control and can even damage the vehicle. When the engine is under low-load conditions (such as when accelerating very gently, or maintaining a constant speed), it is operating in "closed-loop mode." This refers to a feedback loop between the ECU and the oxygen sensor(s) in which the ECU adjusts the quantity of fuel and expects to see a resulting change in the response of the oxygen sensor. This loop forces the engine to operate both slightly lean and slightly rich on successive loops, as it attempts to maintain a mostly stoichiometric ratio on average. If modifications cause the engine to run moderately lean, there will be a slight increase in fuel economy, sometimes at the expense of increased NOx emissions, much higher exhaust gas temperatures, and sometimes a slight increase in power that can quickly turn into misfires and a drastic loss of power, as well as potential engine damage, at ultra-lean air-to-fuel ratios. If modifications cause the engine to run rich, then there will be a slight increase in power to a point (after which the engine starts flooding from too much unburned fuel), but at the cost of decreased fuel economy, and an increase in unburned hydrocarbons in the exhaust which causes overheating of the catalytic converter. Prolonged operation at rich mixtures can cause catastrophic failure of the catalytic converter (see backfire). The ECU also controls the spark engine timing along with the fuel injector pulse width, so modifications which alter the engine to operate either too lean or too rich may result in inefficient fuel consumption whenever fuel is ignited too soon or too late in the combustion cycle.

[Stuart Dean]

I didn't read the spec to closely but if the device is adjustable I suspect it also contains a 10p preset pot in addition to a fixed resistor.
Think of it a bit like playing around with the feedback loop on an amp.
Increase the resistor in this loop and results could perhaps be seen as increasing peformance ( might even produce some smoke as well)
Engine remapping is a different thing altogether and peformance could well be improved but as with everything there will almost certainly be some penalties.

[cressy]

i would have though something that increases fuel economy would make the engine run lean. overriding the lambda sensors signal or altering it to make the ecu think there is more oxygen in the exhaust gases will cause the ecu to reduce the fuel going in to compensate for the change in the fuel/air mixture. it relies on the ecu compensating, doesnt do anything by itsself.
more torque and power? again it would have to affect the fuel air mixture to change it. it would need to run richer across the rev range to affect the power output and torque. crossed purposes to affect both.

it would be better to me to have it remapped. its certainly possible to do what they claim as most cars have a reasonably conservative map, but requires the car to be run up on a dyno and its power and torque curve measured. black smoke from a diesel is usually in my experience either a blown turbo oil seal or a faulty lambda sensor causing the car to run too rich. i have to mention though that both the cars ive fixed for this reason were vectras ( a 2.0 turbodiesel and a 2.2 sri) so probably different ecu's to the volvo. interestingly the same symptoms appeared on the 2.0 a few weeks later when it split the diaphram on the actuator.
just be cautious if you buy one and keep an eye on the temp guage

[pre65]

You can't use the extra power as performance and get more economy. You use the extra torque to use a higher gear (and so lower revs) and get economy that way.

I have two friends who run their own garages so will converse with them on the subject.

[Mike H]

Even remapping for more power etc., as for example racing stock vehicles, also makes fuel usage worse and can also wear the engine out faster.

[spresto9]

£99 is a good price, at today's fuel prices even a small increase in mpg will soon pay for it!
See T/C
"If within the first 30 days from point of ordering you decide not to keep the system, then we will refund your purchase price less outgoing postage costs"
Whats to lose?
Half an hours work?
Regards
spresto9

[/quote]

[Neal]

I've used a similar device for years. The simple ones as stated are just a simple resistor that fools the ECU into dumping more fuel into the cylinders resulting in lots of black smoke. Avoid these.

The more 'intelligent' ones monitor the ECU pulse signal to the injectors and self adapt to a certain extent...the one I currently have makes the car feel normal up to a certain throttle input then takes over and provides the power increase...this again though is achieved by allowing more fuel into the cylinder. If the device is adjustable then theres a good chance it is not just a simple resistor in a box...the claims of 25 or 35% performance increase should be looked at with a sceptical eye as you are never sure exactly what stree you are placing the engine under.

As for Fuel consumption these boxes screw up any on-board MPG meter and you will find your MPG drop....not because they dont work but because your right foot will feel a lot heavier than before!

[Ali Tait]

I'm soon to get a diesel company car, and have been looking at these, mostly because I'm more interested in saving on fuel costs. I've been looking at the DTUK site. These are not cheap, but I've not found a single negative comment whilst hunting around the web. Apparently they sell a large number on the continent, and the DTUK site is just the British franchise for the brand. Also very good to deal with by all accounts.