Is this a sound design?

[EliteBeanDip]

I was going for a moderately priced engine that ran on regular gas and got good mileage if put into a small car. My question is: Would a car with this engine be able to drive normally? (It certainly wouldn't be fast) It seems like I went overboard trying to get this thing to be efficient at a low RPM. Engine stats in the picture.

[deanwells1234]

I was going for a moderately priced engine that ran on regular gas and got good mileage if put into a small car. My question is: Would a car with this engine be able to drive normally? (It certainly wouldn't be fast) It seems like I went overboard trying to get this thing to be efficient at a low RPM. Engine stats in the picture.

sure it would be able to drive! it has 132HP which is perfectly fine HP for a smaller car engine! I just dont see why you made this a turbo? is it for the ECON numbers? it just really raises your service price and probablly lowers your MTBF. just want to know why? also you could optimize the engine for higher AKI to be able to "say" you have a better engine then you do because no one really uses the best Gas but if it is optimized for lower AKI then you cant put premium Gas into the engine... which doesnt make sense to me

[EliteBeanDip]

sure it would be able to drive! it has 132HP which is perfectly fine HP for a smaller car engine! I just dont see why you made this a turbo? is it for the ECON numbers? it just really raises your service price and probablly lowers your MTBF. just want to know why? also you could optimize the engine for higher AKI to be able to "say" you have a better engine then you do because no one really uses the best Gas but if it is optimized for lower AKI then you cant put premium Gas into the engine... which doesnt make sense to me

The turbo does increase service costs, as well as the material cost. I used it mostly to get some more power while still keeping a high economy at low rpm with the turbo tuned to spin up easily. As for the AKI, the engine is optimized to run on 86.4 (regular unleaded) so that's all you'd have to put in it, while putting in anything above 86.4 would cause no harm. As far as I know, Automation doesn't have a feature to automatically de-tune your engine made for premium gas to run on regular. Tuning my engine for 90.3 (premium) and filling up at the pump with 86.4 could cause knocking.

On a side note I could easily set the engine to run on a higher octane by advancing the ignition timing.

[Cheeseman]

34% is amazing fuel efficiency, but in an engine this size the fuel economy won't be brilliant comparing it to cars with similarly powered engines. 132 bhp is easily possible in a turbocharged engine half the size, and because of this, half the amount of fuel will be injected into the cylinders. In other words a 1.25-litre engine with 17% efficiency will be just as eco-friendly as this engine. I have made a ~160 bhp 2.0-litre turbocharged engine with 30% efficiency for my car company Lystex. To make something more cost efficient and reduce the service costs, make a smaller turbocharged engine with a bit more oomph and when you put it into the car it will be more economical and powerful than your 2.5. Hope this helps!

Also, diesels can rev more than this, so see if you can make the engine rev a bit more, but this isn't a huge problem.

[deanwells1234]

sure it would be able to drive! it has 132HP which is perfectly fine HP for a smaller car engine! I just dont see why you made this a turbo? is it for the ECON numbers? it just really raises your service price and probablly lowers your MTBF. just want to know why? also you could optimize the engine for higher AKI to be able to "say" you have a better engine then you do because no one really uses the best Gas but if it is optimized for lower AKI then you cant put premium Gas into the engine... which doesnt make sense to me

The turbo does increase service costs, as well as the material cost. I used it mostly to get some more power while still keeping a high economy at low rpm with the turbo tuned to spin up easily. As for the AKI, the engine is optimized to run on 86.4 (regular unleaded) so that's all you'd have to put in it, while putting in anything above 86.4 would cause no harm. As far as I know, Automation doesn't have a feature to automatically de-tune your engine made for premium gas to run on regular. Tuning my engine for 90.3 (premium) and filling up at the pump with 86.4 could cause knocking.

On a side note I could easily set the engine to run on a higher octane by advancing the ignition timing.

keep your fuel on 86.4 AKI and make tune it to 90.3, your engine will knock and not run. on the other hand have the engine on 90.3 AKI and tune it to 86.4 and you will have no knock. basically you want your engines to be able to run on all gas types, because people want to sometimes use the best! even if the majority doesnt

[EliteBeanDip]

34% is amazing fuel efficiency, but in an engine this size the fuel economy won't be brilliant comparing it to cars with similarly powered engines. 132 bhp is easily possible in a turbocharged engine half the size, and because of this, half the amount of fuel will be injected into the cylinders. In other words a 1.25-litre engine with 17% efficiency will be just as eco-friendly as this engine. I have made a ~160 bhp 2.0-litre turbocharged engine with 30% efficiency for my car company Lystex. To make something more cost efficient and reduce the service costs, make a smaller turbocharged engine with a bit more oomph and when you put it into the car it will be more economical and powerful than your 2.5. Hope this helps!

Also, diesels can rev more than this, so see if you can make the engine rev a bit more, but this isn't a huge problem.

Thanks for the tips. I was stuck on getting bigger numbers for efficiency. I hadn't thought about a smaller engine with a lower %. (that would reduce cost, weight, everything.) Did that engine produce most of its power at high RPM though? This engine is most efficient between 1900 - 2100 rpm. Also, the rev limiter is low on this engine since it was starting to get diminishing returns over 5k and it helps the MTBF a little bit.

sure it would be able to drive! it has 132HP which is perfectly fine HP for a smaller car engine! I just dont see why you made this a turbo? is it for the ECON numbers? it just really raises your service price and probablly lowers your MTBF. just want to know why? also you could optimize the engine for higher AKI to be able to "say" you have a better engine then you do because no one really uses the best Gas but if it is optimized for lower AKI then you cant put premium Gas into the engine... which doesnt make sense to me

The turbo does increase service costs, as well as the material cost. I used it mostly to get some more power while still keeping a high economy at low rpm with the turbo tuned to spin up easily. As for the AKI, the engine is optimized to run on 86.4 (regular unleaded) so that's all you'd have to put in it, while putting in anything above 86.4 would cause no harm. As far as I know, Automation doesn't have a feature to automatically de-tune your engine made for premium gas to run on regular. Tuning my engine for 90.3 (premium) and filling up at the pump with 86.4 could cause knocking.

On a side note I could easily set the engine to run on a higher octane by advancing the ignition timing.

keep your fuel on 86.4 AKI and make tune it to 90.3, your engine will knock and not run. on the other hand have the engine on 90.3 AKI and tune it to 86.4 and you will have no knock. basically you want your engines to be able to run on all gas types, because people want to sometimes use the best! even if the majority doesnt

Maybe I'm explaining or reading this wrong, but the engine currently runs at 86.4 and switching the fuel type to 90.3 has no ill effects. If I were to design it to run at 90.3 then select the 86.4 fuel type, it would cause engine knock in the designer.

[Cheeseman]

The reason why the engine performs at very little revs and doesn't do much afterwards may be down to your cam profile. Try increasing it and it should give you more power and a lower octane rating therefore meaning you can increase the compression or advance the ignition timing. Yes, it will effect efficiency, but the performance improvements will more than make up for it. If there is no effect, which I suspect won't be the case, it is because you have VVL and that you have set it too low (and don't go using it if you haven't, the engine's performance will change entirely and will become much pricier). If you do this and have increased the revs and discovered a rather worrying decrease in MTBF, it may be down to the stroke being to high. Reduce the stroke (making the engine capacity smaller), and if you feel you need to (which you might not), increase the bore. If you still have MTBF problems, upgrade other bottom end parts.

I think that was thorough enough. Hope this helped!!