EcoPerformance Engine - Community Challenge

I know this has been done before but I want to have a crack at it. The aim is to design an engine that gives the best fuel efficiency for the given performance index while taking into account engine size and reliability, so you’re not focusing on one thing like the most power or just economy alone. The formula for working out scoring and you can enter it into Excel, LibreOffice or whatever you use goes a little something like this.

(Performance Index/Variant Capacity CC) * Fuel Efficiency * ((Fuel Efficiency * Reliability)^0,5+100)

So a few things about the engine design:

Year: 2020
Layout: Inline, V or Boxer
Cylinders: 3, 4, 5 or 6
Head & Block Material: Any
Family Capacity: Must have a 3mm overbore from the variant capacity
Head & Valves: Any
VVL: Any
Crank: Any
Conrods: Cast to Lightweight Forged but not Titanium
Pistons: Any but you’ll probably want Low Friction
Variant Capacity: Any
Compression: Any
Cam Profile: Any
VVL: Any
VVT: Any
Turbo: Is going to be a must to get the best score
Fuel System: Probably going to get the best from Direct Injection
Configuration: Single, twin or per cylinder
Intake: Standard only
Fuel Type: Premium 95 only
Fuel Mix: Any
Ignition Timing: Any
RPM Limit: Any
Exhaust: Single or Dual
Exhaust Valve: Any
Exhaust Diameter: Keep it realistic/reasonable
Cat: Three Way Only
1st Muffler: Baffled, Reverse or Straight through only
2nd Muffler: Reverse Only

Quality sliders: Max only of 5 points to be used where you like. You can choose to put all 5 on one slider or distribute 1 point over 5 quality sliders, whatever works best for a better final score.

Engines will be categorised by Variant Capacity, maybe later by engine layout.

If you want to be a part of this community challenge then submit your engine design by starting your post with the Family - Variant engine name as follows:

Family: Your username or company name, Variant Litre, [Family Litre], Engine Layout, Valve Layout
Variant: If VVL or VVT or if both VVLT, Fuel System, [formula score].

Then submit five screen shots of each of the five engine sections.

1.1 Litre Category
1st. ARAIYRA 1.1 [1.0] B4 DOHC 16V - VVLT DI [517.6]

2.1 Litre Category
1st. ZoomZoomer32 Toronado 2045 I4 DOHC-VVT/Di (316.84)

2.8 Litre Category
1st. Hshan 2.8 [3.0] I6 DOHC 24v - VVLT DI [555.2]
2nd. Zephorus 2.8 [3.0] I6 DOHC 24v - VVLT DI [548.3]
3rd. Gullray 2.8 [3.0] I6 DOHC 30v - VVT DI [381.3]
4th. Zephorus 2.8 [3.0] I6 DOHC 24v - VVLT DI [299.2]

Gullray 2.8 [3.0] I6 DOHC 30v - VVT DI [381.3]

Given that aluminum/silicon is superior in most aspects to pure aluminum as a block or head material once it becomes available, why not allow that instead?

Can do but it wont change the score, I’ll change it to “any”, good shout though

I like the idea, though it’s a little messy in execution right now :stuck_out_tongue:

First, a simplified formula that works the same:
Perf/CC * Eff * ((Eff * Rel)^0,5+100)

Second, no need to write the requirements for things that can be “any” - that’s just clutter and wastes both your and participants time. Simple “all not mentioned things are up to your decision” would suffice.

Next, what is it with that “Must have a 3mm overbore from the variant capacity”? Seems like a thing that you have to remember when making the engine despite it making no real difference.

Minor detail - denoting number of turbos is redundant, since it’s always the same as the number of engine banks - one for inlines, two for Vs and boxers.

Major suggestion - rigid quality point limit is all fine, but it basically narrows down the engineering decisions to one scheme of a turbo I6 with DOHC 4v + VVL and DFI - that’s the most efficient but also very complex. A system based on engineering time and maybe cost would allow some variety.

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Thanks for your input, this is totally what I want, a community challenge with everyone’s input to get the best output. So I looked at your formula and I thought “that’s far too simple” but your totally right, that’s less messy than my formula so I’ll update the main post

I thought the same but there is always a few people who need a bit of extra guidance so if the info is not maximised first time I’ll end up having to constantly explain later.

This is some overhead for a later challenge that I’m thinking ahead for…:thinking::wink: now the cats out the bag

Fair enough, we can change this to fit in

Tough one this, I think as most motor companies are based on years and years of experience the time and less so, cost, isn’t so much of an issue. I think this is even modelled in the Automation Campaign but we cant do this on a one off engine build. I’m open to suggestions on this.

Oh no I6 meta strikes again. Although this challenge is quite fun, it would be interesting to run it either again or slightly different when the turbo revamp hits. Anyway, Currently sat at 40.6% :wink:

Also, here’s an excel spreadsheet incase you don’t know what you’re doing.
I assume this is right and people can view it etc


Think I’m done. I think the points changed on the equation since op posted their engine name Because i totally didn’t chase that score for 1 hour
in fact that they have, their score is actually 237.7

Zephorus 2.8 [3.0] I6 DOHC 24v - VVLT DI [299.2]

hah now time to let everyone else copy.

Family Page

Bottom End

Top end


Fuel System
Come on, did you really think I’d put quality anywhere else?

hah cringe exhaust, well actually it is reasonable because the sound is still only at 35

So yeah, go copy, you’ll be a few points off. 2 hours minmaxing well spent.
Perf ------ CC’s ------- Eff ------ Reliability ------- Total Score

@Sky-High I worked your score to be more like 548.3, but… 203mm diam exhaust :thinking:

Not sure how i got the score wrong, this is the equation i put in to excel.


Anyway, If you’re allowing LFC pistons on a “performance” engine, you can forget any “realism” elsewhere.

You lost one bracket, that way you add flat 100 to your score instead of multiplying it by some factors.

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Ah right, That would be excels fault, it said it wasn’t needed :joy: ah well, I’ll change that then.


This engine is so dumb. The challenge isn’t complicated, so there’s basically one correct way to do it, and then it’s just a matter of some fiddling with the numbers. More of a patience and luck challenge. Therefore I’m on the top for now, but by tiny fraction. I think it would be more interesting if we were designing the engine for a car, with less defined, yet more limiting requirements (like cost of the car with that engine, regardless of the quality used).

Anyway, here’s the engine. I think going for a smaller I6 could potentially give even better score, as going bigger makes it worse. Oh, and I forgot to name it properly, so have it here:

Hshan 2.8 [3.0] I6 DOHC 24v - VVLT DI [555.2]

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ARAIYRA 1.1 [1.0] B4 DOHC 16V - VVLT DI [517.6]

This is what happens when someone with a lot of time on their hands attempts to buck the trend of 3-ish litre I6s.

Tell me if I’ve screwed up anywhere.


ZoomZoomer32 Toronado 2045 I4 DOHC-VVT/Di (316.84)

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Was the point of this engine other that getting a high score in this challenge? Because for that there are some unoptimal choices. (BTW, turbo presets aren’t really good). Also you forgot one screenshot :stuck_out_tongue:

So guys, I wanted something for engine designers only as not everyone wants too or has the time to design a whole car start to finish. As I called this a community challenge I want everyone to contribute including the rule set and or objective to something that we can all agree on. I just chucked it out there to get something started so I went for designing an engine optimised for as much performance while returning the best economy achievable for said performance.

if you or anyone else wants to change the direction I’m open to that so long as we all agree and stick to it going forwards.

What I noticed in a lot of the challenges here was there was mostly one out right winner and or runners up. But I’ve done it in litre capacity so everyone gets a shot at being in 1st place in their chosen category.

If anyone has further input to this challenge I’m open the changes needed to develop it.

I didn’t really have that much time to do it, tbh.
I didn’t notice it. Thank you for letting me know!

Ok, so, few little tips for the future. 4v + VVL (with very low 1st profile and power-focused 2nd) is more efficient than 5v with comparable performance - though it’s heavy, complex and expensive. Top end quality is mostly useful for revving higher. Eco-turbo should have as small turbine as feasible with high AR ratio (when you need more power first increase the AR, then turbine, if you need less first shrink the turbine, then AR). Intercooler should always be at 0.99-1.0 flow.

BTW, do I see Lego Digital Designer on that taskbar? I liked that program.

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Thank you very much for these tips!
Yeah, it’s LDD. I don’t really use it that much now, tbh, but it was and still is very useful to create stuff that you can’t make irl and to save the instructions for something you made