Help us out: Engine Designer Revamp

[Daffyflyer]

Already got that one in mind, because of the same reasons you stated

[Mingan]

VVT on 5 valves is coming.

Fuel mixture can't have a value as it would be changing all the time, under load at high rpm it might be 11:1 but at cruise it might be 18:1, the fuel mixture slider represents "On average, how rich is this engine tuned"

Yeah, exactly. I find fuel mixture difficult to tune. The help window says: "A ratio of 14.7 parts of air to 1 part of fuel is... the ideal ratio..." How exactly can we make this ideal ratio with a slider from 0-100? It's too complex to use in this way, unless the slider represents the amount of air:fuel, so 14-15 represents 14.7:1 air:fuel?

It doesn't work this way though, does it?

Hi everyone!

I too think the fuel mixture slider is confusing, but I guess "fixing" it would require more complex mixture tuning procedure than you have planned for this game. I would really love to see more realistic adjustments with many things, like cams and ignition timing (degrees anyone?) but if you are only going to make this game semi-realistic I guess my complaints won't matter.

[Leafy]

It would also be great if the external size of the engine was shown as the displacement changes are made. Having to keep going back to testing and running it to see a change when doing that schenario with limits on the size was annoying.

Adding in a slider for factor of safety. There are somethings that we cant choose that effect the reliability of an engine, like cylinder bore lining thickness, rocker strength, etc. And those can be a reliability vs lightness vs cheapness type thing.

[Bmotley]

I've noticed that when I am working on a pushrod engine and turn up the compression, one of the valves disappears into the piston head.

[Theking]

A few humble suggestions here, things that bothered me after playing all the fantastic scenarios:


#1 : Dyno graphs: It seems the hp calculation is off. If calculated correctly the hp and torque will be equal at 5252 rpm.. Which it is not. Since low end torque (should) have a big influence on economy and emissions, this is actually a major issue for the realism of the engine..

#2 : Flywheel wheight: "normal" wheight is ~18KG in I4 engines.

#3 : Its all in the heads - The heads should be given more options. Port size, port angle, valve size, chamber shape and even intake runners have a very high impact on an engine. Perhaps adding those up in a single line adjusterbar for simplisity maybee named "agressiveness" or something. Either way they are to important to disregard.

#4 : Ignition timing: Sorry, but Ive tuned 1 million engines, and not once had a max ignition timing of more than 36 degrees. Also options like old points, early age electronic, ECU controlled and even amplifiers, COP or dizzy ++. These are highly important for both cost, emissions and power.

#5 : Compression ratio: It seems to be very hard to gain power with high comp engines. Increasing cam duration should have an higher influence on RON when you have high compression engines. I would therefore suggest to implement 2 factors in camshafts, Duration and lift. Research shows that the lift (among many other factors) determines the power of the engine, while the duration tells at what RPM you get it (if nothing else change). But higher duration allows for more compression/ignition timing etc and can allow even higher power at the expence of economy ++. This becomes even more a factor in turbocharged engines. Dont forget though, higher lift will increase overlap.

#6: OHC seems to have an advantage over all other designes when it comes to power?

#7 : AF ratios: This should just be removed. Perhaps a cost for tuning effort could be used, but in general any carb will give poor fuel mixture at practicly all RPM`s while a multipoint fuel injection gives great mixture at all RPM`s.



Thats it for now. Great game though, cant wait to see it complete!

[Vain]

I noticed a few things, but I'm not sure which of them are this way by design:
1. I may be misinterpreting the "responsiveness" value, but it doesn't behave like I would expect it to in relation to the cam profile. I can push the cam-profile to 100 and get a torque curve that resembles one from a jet engine. The responsiveness-rating of such an engine is very good despite the fact that it'd take half a minute to rev to the limiter in neutral. Responsiveness should take the ratio of available torque at several rpms to the engine's inertia into account.
2. Similarly the bore/stroke-ratio doesn't appear to have the kind of influence on responsiveness I would expect. I didn't run the math but I would expect that given identical combustion volume the engine with the lower bore/stroke-ratio would have a higher angular inertia and thus feel less responsive to the driver.
3. The effect of the valve-timing slider appears not to be very useful. Right now I either leave it at the bottom for all engines or tune it so it creates a little torque-bump to boost maximum torque. I think generally the mechanic doesn't add a lot to the gameplay.

[Daffyflyer]

Yeah, responsiveness is more how snappy it is on the throttle, how well you can rev match shifts, that kind of thing. How torquey and "midrangey" it is will be determined from the torque curve and combined with the gearing etc will determine a lot about how the car feels to drive.


2: Will investigate this one, interesting thought.


3: Yeah, I'm not 100% a fan of this right now, will consider removing it I think

[Vain]

Regarding responsiveness:
It's been discussed some time that the term "responsiveness" is unintuitive. But that's not your fault, the concept of moment of inertia is just not well known to the broad public. I'd like to suggest that all testing results get mouse-over-tooltips to avoid further confusion. That would be the place for the layman's terms explanation and the more precise definition. That would also allow you to add more test results.

[dabbott89]

Just a few (it started off as a few anyway ) thoughts/ suggestions from myself;

1) Consider adding options for wet/dry sumps, the wet sump would be more reliable in low performance applications and much cheaper. The dry sump should add cost and servicing costs but increase reliability in high performance applications and allow for a more compact bottom end.

2) Are the grades of steel for forged and billet cranks uniform? If so the forged with it's better grain structure would be more resistant to long term fatigue for regular applications rather than the billet machined crank, which only has the directional flow of the original extrusion (that said you can impart this quality via heat treatment).

3) Will there be simulation of one off costs and tooling costs for the manufacturing processes later in the game? For instance to refer back to the crank, a forged option has a large set up cost but a much reduced material and labour cost in comparison to a machined crank which has negligable set up cost (providing the machines/ heat treatment facilities are available) but high tooling costs. I appreciate this may not add much fun to the game and perhaps add uneccasary depth but I thought I'd raise it anyway!

4) An option to choose between belt, chain and geared engine chests would be appreciated. It would provide an extra dimension in the cost/ reliability battle and another tool to get those extra pesky M/revs

5) Valve return systems, choosing between springs and pneumatic return systems would allow for more modern automobiles to achieve better fuel economy and performance and allowing much higher RPM's well beyond the natural frequency of valve springs (about 12krpm I recall). The opportunity to model Fiat's multi air engine or a 2006 21k rpm F1 car engine would be awesome!

6) More options to choose material will always be welcome to me though I appreciate this may not add to the wider appeal of the game, options for various surface and heat treatments would follow the same point. Maybe expansion packs of extra detail for the particularly anorack amongst us would be a long term option?

7) Will the option for clutch type be part of the gearbox tool or should that be part of the engine designer?

Finally, I just want to say what a fanastic game the demo alone is, it's been utterly engrossing from day 1!

[noisymime]

Not sure if this has been covered elsewhere, but the construction year timings for fuel injection seem REALLY off. Many Japanese cars had electronic multipoint injection in the late 70's, but they don't appear until you wind the game year up to 1993 (1988 for single point injection). Seems weird.

Maybe change the efficiency of the FI based on the year set. ECU's in 1980 were incredibly limited compared to 1990, which were again primitive compared to something from 2000. Maybe add something like sequential vs batch injection (affects emissions, responsiveness efficiency etc) and have it's availability based off the year.

[Daffyflyer]

One thing to note is that the year of availability is when its freely available to everyone. In the actual game, if you research you can unlock them ahead of that date, but it wasn't till the early 90s that EFI was absolutely ubiquitous, it was only used by the companies that had put in the R&D to get it working for them

[elmanos]

Issue description: No noticeable change of sound on hi/low cam change
Possible solution: Make it louder and deeper at hi cams
Important because: Sound better, and more right

[Daffyflyer]

^already done, just not released in the public version yet

[elmanos]

Also will you make the "valves" in the throttle bodies move, and make an animation on the hi-low cam change over when on dyno?

[Arnerdo]

As ive seen a few other places in this forum, i would really like al little more realism in the mixture, cam and ignition metrics.
100 Fuel Mixture? 100 cam profile? 100 ignition timing? Its confusing and abstract, and i cant really associate it with anything.. I understand that the cam slider is probably the most complex one to change; it would at least need lift and duation (i would be very happy with that).. But the two other, ign. timing and mixture, would really just need a name and range for the variable, like degrees [30,-10] and fuel/air ratio [x,y].