Lambda meter helps keep engines in tune

Edited by the Engineeringtalk editorial team Oct 20, 2005

One of the most important items of equipment for live mapping is the air-fuel ratio (or lambda) meter, and Motorsport Developments has chosen the ECM AFRecorder 1200.

Motorsport Developments is one of the UK's leading vehicle engine tuning specialists, with particular expertise in modifying engine management systems and "live" mapping, wherein the engine's management software is fine-tuned while the car is being driven, which is far more accurate than "chipping" or mapping on either an engine dynamometer or rolling road.

One of the most important items of equipment for live mapping is the air-fuel ratio (or lambda) meter, and Motorsport Developments has chosen the ECM AFRecorder 1200 supplied exclusively in the UK by Labcell.

Getting the air-fuel ratio right for a given set of engine parameters is vital for maximising power output, optimising fuel economy and avoiding engine damage or unacceptable emissions.

One of the problems with dynamometer set-ups is that the actual operating conditions found on the road cannot be fully simulated.

As a result, a safety margin has to be built in, which effectively robs the engine of a small amount of power.

Live mapping, on the other hand, enables tighter safety margins to be used, so more of the potential power output can be realised without risking damage to the engine through detonation.

Needless to say, the accuracy of the air-fuel ratio meter is critical.

Prior to purchasing the AFRecorder, Motorsport Developments was using an air-fuel ratio meter from another supplier.

However, despite its high cost, this instrument proved thoroughly unreliable.

Motorsport Developments was therefore at risk of letting down customers.

Moreover, with contracts such as those for setting up Formula Ford cars, failure to complete the mapping in time could lead to delayed races and hefty circuit cancellation fees.

Having discussed the issue with others in the automotive engine tuning industry, Stewart Sanderson, who is one of the partners in Motorsport Developments, decided to try the AFRecorder 1200 instead.

In comparison, this model had the same or better specification than the rejected alternative, plus it had the benefit of being more portable.

Bearing in mind the way the instrument is usually hung from the car's rear-view mirror during testing, this is a considerable benefit.

Stewart Sanderson comments: "We have used the AFRecorder almost every day for the past two years and it has never failed".

"Occasionally we return the instrument to Labcell for checking the calibration - for which there is no charge - and we are always given an honest opinion".

"We have to trust what they say, and they have never tried to sell us a replacement UEGO [universal exhaust gas oxygen] sensor".

He continues: "Whenever we have a technical query, we are always able to speak to the right person and get an answer very quickly, which is infinitely better than our previous supplier".

"In fact nothing ever seems to be too much trouble; the service we get from Labcell is absolutely 100%, and I would even go so far as to say Labcell is probably the best company I have ever dealt with".

The ECM AFRecorder 1200 that Motorsport Developments uses is a compact, fully-featured instrument with measurement and recording capability.

It has a measurement range of 6 to 150 AFR (0.4 to 10 lambda), with an accuracy of +/-0.6% at stoichiometric ratios and +/-0.9% elsewhere.

In addition it has an RS-232 digital serial output (as used by Motorsport Developments) and a 0-5V linearised, user-programmable output.

Most important, however, is the reliability of the instrument - which has been proven by Motorsport Developments over the past two years.