Matra Murena 2.2L built in conjunction with Talbot.
The Matra Murena is a nice vintage sports car.
The car is known as the sports car with 3 seats in the front.
Like its predecessor the Simca Matra Bagheera.
We converted a Matra Murena to LPG for one of our customers.
His goal was to have the car converted without losing the car's
superb driving characteristics.
Because the car has a centrally placed engine the tank can't be
installed in the boot, otherwise the car will get out of balance.
Therefore we installed a 55 litres tank in the front of the car in the
space intended for the spare wheel.
The customer wanted a proper mileage (travel range on one fill) and virtual no performance loss.
For the conversion we used the standard philosophy for designing LPG systems.
2.2 litres 4 cylinder centrally placed engine.
We started with a 45 mm mixer to be able to get the best performance.
Than we installed a TAP and an ECOMAX. The result was virtual no
When testing the car by accelerating in 5th gear (from low revs to top revs.) the
difference between running on petrol
without a mixer was 24 seconds and on LPG 25 seconds.
Later on we also put the Murena on the our dyno tester.
We measured a performance difference of less than 3bhp.
Less than 2.5% performance difference is negligible.
The fuel consumption on average in Holland was 9.2 km on 1 litre of LPG (26 mpg) and
in Germany on the Autobahn 8.3 km on 1 litre (23.5 mpg).
The test was done in both cases over a distance of 1000 km.
In Holland the car was used around town and on a run (daily use) with max.
speed of 130 km/h.
In Germany we used the car for long distance traveling during the day.
Most of the time the car was driven with a speed between 120 and 160 km/h (75 and 100 mph)
and occasionally over 180 km/h (112 mph).
The traveling distance was up to 420 km (260 miles) on one fill.
To improve the mileage we designed and installed a fuel cut off system on the mixer LPG system.
As soon as the driver backs off the throttle the LPG flow to the engine is
As soon as the revs. drop beneath a pre-adjusted level the LPG flow comes back and the engine
keeps on running.
The first results of the fuel cut-off show an additional drop of 10% in the cars fuel consumption.
Which means that the mileage on LPG is more or less equal to petrol.
For best performance possible we removed the carb. and installed an 65
mm throttle valve and an 50mm mixer.
We also replaced the ECOMAX by a Lambda controlled main flow adjuster.
The result was superb.
We measured on LPG 141 bhp @ 6000 rpm and 198 NM @ 3560 rpm.
On petrol we measured 117 bhp @ 5750 rpm and 173 NM @ 2840 rpm.
20.5% more power on LPG!
On the run (driving between 110 and 130 km/h) the engine uses 1 litre of LPG every 10.5 km.