4d SimRacing Blog

Be warned, this post is more of a rant.  I wrote it a while ago and wasn’t sure if I was going to post it.

Normally aspirated engines such as those in Formula 1 can be adjusted in many ways on the fly.  Mixture, ignition timing, valve timing, and maximum throttle to name a few.   Engine mixture in F1 is often a rotational switch on the steering wheel.  From my understanding, F1 engines run on the lean side of optimum to save a sizable amount of fuel for relatively small amount of power loss.  It would be better to save a significant amount of weight by adding less fuel than having a small amount more power.  However, when needed, the drivers can up the mixture setting to help pass competitors.

ISI has included a “boost’ setting in their F1 cars, but to me, its implementation is obviously unrealistic.  Maybe I’m being thick, but I can not see a desirable combination of real-life engine settings that would increase power and fuel use while decreasing torque and engine life (by a large amount).  Real life engine mixture, timing, etc,  do not produce these results.  Sure, it may add another setup option to play with, but it is anything but realistic.  The problem persists when mod makers copy ISI’s example.  Now we have nearly every F1 mod (and many others) with this unrealistic engine boost setting.

I tried to fix the way this boost setting works for rF1.  Basically I wanted to turn it into the engine mixture setting we know real F1 teams have.  However, its most likely that this is impossible in the practical world.  Let me explain.  It is possible to modify the engine boost variables so that it gives more power at the cost of fuel, just like it should.  However, rF adds engine temperature when fuel is burnt.  This means the rich setting would actually run hotter, and to such a degree that it can half the engine’s life.  The poor engine life can’t even be countered properly by  changing the ‘reliability with boost’ variable because engine wear with temperature is exponential, where as the change with boost is linear.

This boost setting was probably originally meant for modeling turbochargers because it fits them so much better.  Increasing turbocharger boost does increase power and fuel use while decreasing engine reliability (as well as torque if things heatsoak).   I don’t think the way it is integrated into the physics engine should be changed -  I just think it should not be included in cars that it doesn’t belong in.

Hopefully ISI will include a separate setting for engine mixture in rF2.  Until then, engine boost is disabled in rF1.