Allegedly MB massaged the M113 performance figures so that they would be more favourable than the outgoing M119, and of course the latter was downgraded to make the 600SL performance appear to be comparatively better. So in practice I doubt there would be much in it in terms of 0-60 performance between the M113 and M119, other than the possibility that the M119 might indeed be quicker.
Fathertime, we are counting on you to solve this dilemma by taking a M113 and M119 head to head on a timed drag strip.
I believe there are more possibilities to extract more performance from the M119 Cis-e engines over the M113.
So, we know that fuel trim is set to roughly 14:1, which is a trade off between max fuel economy at 14.5:1 and max torque at roughly 12.5:1 air fuel ratio.
On the M119 Cis-e engine, if you strive to run at max torque fuelling by adjusting the Lambda adjustment screw, your efforts will be thwarted because the closed feedback loop won’t let you reap the potential performance benefits. The electro hydraulic actuator (EHA) on the side of the fuel distributor will back off the fuel within its predefined operating window determined by the fuel map in the KE control module N3.
The N3 module does this with input from the O2 sensor (and other sensors) and alters the magnitude and direction of the current to the EHA in order to electronically adjust the fuel trim. A positive current enriches, and a negative leans, depending on the baseline setting basically.
So, if one were to splice a rectifier diode in one of the two wires to the EHA, the diode would only permit current to flow in one direction. So if you oriented the diode so that the EHA only receives inputs on the enriching side of the baseline mixture setting, presumably the EHA would not be able to lean off the fuel beyond the baseline setting. Therefore you potentially could set the baseline lambda to a predefined setting where maximum torque would be now achievable.
Although the EHA would still be able to lean off the fuel back to the limit of the baseline mixture setting, the downside is that the full fuel cut off on deceleration feature on over-run would be defeated. The only control on fuel trim at this point would be mechanical by the air flow sensor. So under engine breaking at high revs (I.e. downhill, high speed, low gear) this could lead to excess unburnt fuel being dumped into the exhaust. Furthermore, if you set the baseline adjustment screw too rich, the EHA would not be able to compensate suffiently to prevent excess unburnt fuel entering the exhaust system. So you would need to consider the risks and the effect of this on your CATs.
This is only an idea, and is offered for others to consider the pros and cons for track use where the CATs have been removed and the engine can be properly set up.
Of course an excess of fuelling would elicit a signal from the engine knock sensors and the ECU would retard the timing.
Crazy idea? Maybe. I let you decide.
I thought I’d share this. The idea is not even fully developed by a long chalk, so if you choose to experiment with this idea, you do so at your own risk.