nope, im using sankrit name as usual for this round
making super cheap economical car really not my strong suit, the interior is terrible because i cant tweak the engine to be more efficient but at least i tried 
Great writeup @koolkei, The reason for the looks is that itâs a budgetversion of this one: AUTOMATION PRO LEAGUE 3rd Round: 1955 NASCAR Closed due to lack of interest 
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Love how you separated the true contenders from the half-baked wannabes - canât wait for the results! It just shows how challenging this round was.
dude⌠rude much?
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i didnât think my car was that bad? ithe skinny tires gave me better driveability and better economy
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Thats a problem Iâve noticed with small engine running eco turbos is that it is impossible to make them spool early. I noticed that by decreasing the compressor size it actually increased the spool time and so that messed up my usual turbo strategy.
Hmm, Iâll check a few things youâve complained about Iâm not very good at building budget cars, so I might have missed something, but I think most of my choices were somewhat sensible. I6 was surprisingly cheaper than I4 or I3 IIRC.
Power steering ruins my great economy figure, thatâs why I didnât include it.
And as for the viscous differential, well, I kinda forgot it wasnât a Storm car, and clicked it and never looked back.
yeah i kinda know, i4 and i3 are the safe route here want better spooling? i6 turbo will do it, but that will end up with too many parts with such small engine. the problem is the turbo itself. you need to be really amazing with the engine tune to really able to compete with the NA. itâs a land of compromise. turbo is more expensive, also ups the running costs. and people would just prefer the NA if thereâs no real significant advantage in turbos.
just like irl. the daihatsu copen was it? the kei car one is a 660cc turbo, but the exported one has the option of an NA 1.3L i4
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Concise yet thorough and illuminating review of this round and what a diverse set of entries! Now I doubt Iâm still in the running but I hopefully Iâll have learned some tips for the developing market and adjusted the design to address most of them.
Actually, I have a bit of a question for you or any way regarding the use of the low friction cast piston everyone always seems to say it has a reliability penalty but it does still boost economy a fair bit. So then when is it ever valid to use it and with which engine internals?
Low friction pistons donât have any reliability penalty directly, but they can withstand much lower revs - even lower than the standard cast, I think. The way I found out to use them effectively is to combine them with a low stroke engine. High stroke alone improves efficiency and (with the same displacement) reduces weight, but oversquare design (high bore, low stroke) with low friction pistons gives even better efficiency* - and, as a side effect of an oversquare design, improves smoothness and allows for higher revs** - at a cost of higher weight, but itâs usually worth it. For me high stroke is useful for extremely efficient engines (pseudo-diesels) or OHV ones, as it allows for the highest revs and perfectly complements OHVâs low weight and small size.
######*than a comparable undersquare design with different pistons
######**compared to a similar oversquare design with low friction pistons - comparable or higher than an undersquare design with standard pistons
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it doesnât effect reliability, as long as itâs revving low enough. low friction pistons are âweakâ and cannot be revved even a little bit. i donât think iâve ever made an engine with low friction cast piston that revved more than 6600.
if youâre clueless how to use them, this should be a good method
- just pick an engine size on roughly what you want.
- pick the low friction cast.
- lower the rev limit down until youâre not losing any significant reliability score anymore.
thatâs the limit of the low friction piston in that particular stroke. yes, just stroke, bore size doesnât effect it directly - now you refine the engine size you want. just remember, the longer the stroke, the lower the revs, and this applies even more significantly to low friction casts.
but also take into consideration that most economy oriented engines have longer stroke than they do bore, because they provide better torque for the size, and undersquared means lighter engine too.
@szafirowy01 well we differ in perspective. this is how i see it. if i want a pure economical engine, just get the stroke as long as reasonably possible. but if you need a little bit of performance, use a square engine at best.
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Pure economical, yes - then long stroke is good. But eco-only focused engine is rarely needed - usually itâs a matter of balance between economy and performance, and low revs usually harm performance pretty badly. Economy is less harmed by an oversquare engine than performance by an undersquare one.
nah mate. bigger capacity, and lower cam profile. same specific power output, more torque, and same if not better fuel economy.
By what I could read, me and Phale seem to have actually taken a similiar approach of the âsuper cheap âŚboxâ while Phaleâs was very much less dodgy, and I struggled to get everything inlcluding infotainment fitted into that little kei body!
I just had to use that kei body! And embrace its drawbacks.
It has absurdly inefficient aero @~1.000 m^2. I had to actually use fully clad just to fulfill the economy requirements within the theme of ârepurposed kei car, slightly altered engine, budget trimâ. This on top of basically stripping out everything and making the panels partially out of glued tin foil 
The engine itself is more reliable than everything else on that car
Also great no-frills style reviews!
Also, so nice from both of you elaborating on the low friction pistons, @szafirowy01 and @koolkei! Also, donât forget that a turbo can make the horses gallop earlier in the RPM range 
Wasnât even mentioning capacity So you canât say ânahâ, as I fully agree on this (capacity and cam profile) 
But about the cam profile - I didnât state it, but I was talking about engines with VVL - in their case combining high revs and economy is not a problem. For the engines without it I didnât find a âperfect balanceâ yet.
@4LGE Yeah, I definitely donât forget about turbo Iâve discovered some interesting things about it, but they werenât particularly useful in this case - displacement and VVL were more or less enough
oh well in the case of VVL then iâm with you. but i personally wouldnât make a economy oriented only engine with VVL in the first place though. only when iâm making a variant do i do that.
Thanks for the tips @szafirowy01 and @koolkei very much appreciated. Iâll have to do some more testing with my engines.
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With basic infotainment my car would have cost $9360 with over 40 comfort 
@Rk38 The way I look at it, there are several ways to make an engine more economical: AFR, cam profile, low friction pistons, compression/ignition, etc. AFR and cam profile come first because (with DI and VVL) itâs easy to choose the most economical options for those without sacrificing performance. But low friction pistons basically force you to compromise performance, so you should only use them when performance isnât necessary and you really need the economy.
It makes sense to pair them with cast/cast since those are the cheapest from a PU perspective and they wonât harm reliability since the pistons are the limiting factor. Going forged is a waste, unless you really care about the smoothness.
Assuming itâs available, I personally wouldnât make any engine without VVL
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If I removed basic infotainment:
The comfort would drop from 31 to 22. But heeey, slight boost in economy and a trivial increase in reliability, which wouldâve allowed me to use semi clad instead, which doesnât drop the price any further, though
Now, what would Tata say? What would Dacia do?