Resistor Swap Gives Honda Insights More Power

A common complaint around modern passenger vehicles is that they are over-reliant on electronics, from overly complex infotainment systems to engines that can’t be fixed on one’s own due to the proprietary computer control systems. But even still, when following the circuits to their ends you’ll still ultimately find a physical piece of hardware. A group of Honda Insight owners are taking advantage of this fact to trick the computers in their cars into higher performance with little more than a handful of resistors.

The relatively simple modification to the first-generation Insight involves a shunt resistor, which lets the computer sense the amount of current being drawn from the hybrid battery and delivered to the electric motor. By changing the resistance of this passive component, the computer thinks that the motor is drawing less current and allows more power to be delivered to the drivetrain than originally intended. With the shunt resistor modified, which can be done with either a bypass resistor or a custom circuit board, the only other change is to upgrade the 100 A fuse near the battery for a larger size.

With these two modifications in place, the electric motor gets an additional 40% power boost, which is around five horsepower. But for an electric motor which can output full torque at zero RPM, this is a significant boost especially for a relatively lightweight car that’s often considered under-powered. It’s a relatively easy, inexpensive modification though which means the boost is a good value, although since these older hybrids are getting along in years the next upgrade might be a new traction battery like we’ve seen in the older Priuses.

Thanks to [Aut0l0g1c] for the tip!

123 thoughts on “Resistor Swap Gives Honda Insights More Power

  1. I’m all for hacking, but increasing torque by 40% without taking into consideration the rest of the drive train and its limitations calls for sheared off/broken parts. Also current capacity of cables and so on…. On a public road I wouldn’t tamper with safety critical parts without thinking the whole thing through.

    1. It’s also worth stating that in many locations, this modification will be highly illegal if you don’t disclose it to the government vehicle inspector and insurance company. Depending on the jurisdiction, simply being caught with it without these disclosures could result in an instant loss of driving license and a hefty fine. The wrong person in the wrong place at the wrong time might even go to prison.

        1. Both. A lot of countries have laws regarding which vehicles are allowed to be on the roads. Any modification to the vehicle that is not within manufacturers specs requires a proof of road worthiness from a variety of agencies. Also, original equipment must also be maintained. We had some extra lights that stay on all the time, to assist other people’s visiblity of the vehicle. “Day lights”… and one broke. To my suprise, the car could not pass inspection (annual inspection) unless they were fixed. Even though there is no law requiring them, because they were originally on the car, they had to be fixed. Now th painful part.. Honda wanted approx $700 for the pair. They are just LEDs. It was wild.

          1. There’s no way, with a price tag of $700 for a housing and LEDs, that there isn’t a MUCH cheaper aftermarket option. If not, send me the broken one and I’d charge you significantly less to fab a new one.

        2. Manufacturers write and sign letter of conformity or similar documents to all different markets cars are sold at.

          It is a statement that tells the car will obey all rules and regulations and they will back these claims fully and are liable if they have given false information.

          There probably are tons of internal testing to ensure that they don’t sign something they cannot achieve. And there is also at least some external testing. Manufacturers probably cheap out and do as much as possible internally. But it it is expensive anyway.

          Thus if you make mechanical or electrical modifications your car it is no longer verifiably certified and compliant with regulation unless specifically tested by entity that the officials can trust. “Trust me bro” coming from hobbyist might not cut it…

          1. That’s not really that fast. It’s about what you should expect from a modest ICE car that isn’t underpowered. For an EV, it’s downright slow. Tesla’s 0-60 on their slowest cars is 5.5 seconds…a little over half…

        1. ireland is like this. you always had to disclose the cubic centimeters of your engine to the government, and if you for instance installed a larger engine and did not disclose this fact, then you would have committed fraud by not paying your full amount of road tax, which was calculated from the size of the engine. also, if you had an accident, the insurance company would not cover any claims against you due to the excessive risk incurred by the extra power.

          1. Exactly, insurance company would run a mile if they found any mods to the car, it wasn’t what they insured.

            Anecdotally I tried to get a loan of a friend’s BMW i5 there last year with 600hp compared to my 115hp diesel ford. Insurance companies all said they wouldnt cover me because of the acceleration difference.
            Not that the insight gets a huge amount more but if there’s any sign of tampering they won’t cover the car regardless of fault.

        2. Seem to remember some countries frown on power mods (France perhaps?) and in the UK I’d expect to have to advise my insurer but, here at least, as long as it passes emissions (for an ICE vehicle obvs.) and the rest of the mandated inspection then nah, no need to inform anyone else.

          1. You’re right. In France, any modification to the power output of your engine must be validated by a state-regulated auditor (les mines). Even if there are no apparent change (like re-programming the ECU for a better injection ratio). In reality through, many vehicle hackers don’t declare them. In case of accident, the insurance can, theoretically proceed to inspection, but there are very few expert able to deal with ECU firmware hacking (this would require having the original firmware to compare with, good luck) or reviewing the electronic circuit (this requires the Gerber of the original PCB with the BOM, good luck) so it’s mainly safe.

            The real issue is, IMHO, the moral and psychological responsibility you can have in case of an accident implying a casualty.

        3. Germany is like that. You are not allowed to make modifications to the vehicle in anyway that affects the safety equipment or the drivetrain.

          For any vehicle you are only allowed stock parts (OEM or aftermarket) or parts from approved alternatives. As an example, it is OK to install aftermarket brake pads on your car. They are type approved for your vehicle, so you are fine. You are not allowed to install a different set of brake calipers in your vehicle unless there’s a type approval for it or you have a special inspection done that may involve actual physical tests of the modified vehicle.

          Wheels are the same. There’s specific wheel sizes listed in the type approval for various cars. If the wheel has a type approval for your car, then you can use it. If not, you’ve got to get a special approval for your car and those wheels.

          Stuff that’s not stock will be noted during the inspection (every 2 years.) If there’s something in the car that’s not on the type approval, then you fail the inspection and can’t drive the car until it is fixed.

          The average policeman isn’t going to be watching for that kind of thing. It is very unlikely that the police will pull you over for not having type approved alloy wheels on your car. If you get pulled over for something else you might get an additional fine and a requirement to fix it.

          What does happen is that people (kids, mostly) modify their mopeds to have more than the allowed power. Those are often noticed in traffic and the police do stop people driving overpowered mopeds – you can be fined and lose your license over that.

          Folks who modify their cars for more power and what have you can have a special inspection done (costs a lot) to get an approval for the changes. You can do that kind of thing as a hobby, it just gets rather expensive.

          If you are involved in an accident and you had non-approved parts in your car, then you will be stuck for a larger part of the responsibility – fines, loss of license, jail time all possible depending on how egregious the violation was and how much it contributed to the accident and damages or deaths caused.

          1. Usually in the EU, if not in Germany, you have some allowance to increase power by 10-20% as long as it doesn’t exceed the best model of that car sold by the same amount. You may have to upgrade the drive-train and brakes to match that “comparison model”. Small volume racing models don’t count.

            There’s all sorts of grandfather rules in place, so the exact allowance depends on the law that was applied when that model of car was made.

          2. ‘They’ made my cousin remove the truck nuts from his Benz.

            To be fair they were hooked up to the trailer light hookup. Aux brake and signal lights. Left, right…My doing, I’m afraid.
            Could have caused an accident. A German might have laughed. Wrecked his car because of the unfamiliar experience. Laughing while driving has to be illegal in Germany. At least on the Autobahn.

            He’s American enough to just remove them before inspection now. None of his patients or partner doctors have noticed ‘the boys’ (or said anything).
            Would a German say anything about something so embarrassing (might lead to laughter)?

            These restrictions have a lot to do with modern German cars sucking so bad. Unmaintainable by design.

      1. Literally every car is like this if you look hard enough. Nobody is in compliance, and nobody is really meant to be. Laws are meant to be applied through bureaucrat discretion and clemency, since everyone is guilty. A source of great and unaccountable power.

        1. That’s regulation vs. law for you.

          Law is clear cut. You’re either in violation or not. Regulation comes to play when law is written so poorly that it’s wide open to interpretation by regulatory agencies that can apply their own discretion over the rulings disregarding the democratic processes and oversight that defines law.

          That’s why people who wish to gain arbitrary powers through the state demand things like “better regulation of the economy” instead of fixing the laws that apply to the case.

      2. This sort of response is the GDPR cookie banner of comments. It’s useless, tells you something you already know (sans exaggeration), and is completely unwelcome. Yet, wherever you go on the internet, there’s some know-it-all commenting, not to contribute to the discussion, but to tell you how physically or legally dangerous it is to engage in the covered topic. Thanks for making the internet better, Dan. You make hall monitors everywhere proud.

      3. This is such an obnoxious take. This is a car with 67 horsepower. It’s gutless and slow. Boosting it to ’72’ horsepower is hardly noticeable. You can get almost the same performance increase by changing the air filter! Do you notify all applicable government bodies when you change a consumable part like that on your car?

        This is impossible to find unless you damn near reverse engineer the car.

    2. That’s what manufacturers have been saying about vehicle mods and, even people fixing their own vehicles. The truth of the matter is, we DO consider the rest of the drivetrain when adding power mods. The truth is, in order to cut on costs of retooling factories for EVERY PART of EVERY MODEL, manufacturers only use a few different engines, transmissions, driveshafts/half shafts, etc. for every vehicle in their lineup. Most of the time, there has been only a small number of minor changes to keep up with regulations (EPA, safety, etc), over decades. The materials cost savings by making unique weaker parts for each lower powered car would take decades to make up for the retooling cost.

      We know that the drivetrain in car X that only puts out 115 HP is used in cars that put 300 horses to the ground, stock. We also know that those drivetrain components have been shown to easily withstand 450+ HP with upgrades made by dealer techs. We know that to go to 600 HP, which upgraded, reengineered aftermarket parts to swap in to handle the power.

      Similarly, in the service manual for every vehicle, there is a list of every wire in the wiring harness. It includes wire gauge, color coding, length, resistance, etc. For added safety, especially with electrical, it is not uncommon to see a safety factor of 4 or 5 (4-5 times the load it will have to carry). There ARE exceptions, so it’s important to check, but it is well known what gauge of wire to use with a given current over a given length. You don’t even have to calculate it. You can just look it up on a table and if you use the results, you will not only be ok, you’ll be great.

      Going one size smaller typically means you will have high resistance and the wire will get warm, but you won’t catch fire unless it’s a long run. I don’t know who this guy is or if he did the requisite checks, so I’d check the forums before trying this. If it’s a popular enough mod, I’ll find a post saying, yeah dude, the wiring from this to this is X gauge, the wiring from that to that is X gauge. We’re talking about Y amps. You could safely double the current. We’re only bumping it up 40%. If that person is wrong, don’t think for a second, 100 people would post and point it out.

    3. Really? 5 horse power? If they are Using parts that will break with only an additional 5 HP I wouldn’t buy the vehicle in the first place. The wire size is another matter, however I doubt they used wire size so close to max current that there was no room for a fudge factor… Unless of course it was built in China.

  2. 40% more power into an electric motor that’s deep inside an engine block and cannot be replaced if you burn a coil…

    We just donated our Gen1 Insight to a local VoTech scool last month. They had to do a month of investigating to see if they could accept it. No scrapper wanted it; the battery is toxic waste and the catalytic converter is Legal Toxic Waste.

    They’ve no shortage of pep as stock; they’re powerful enough to get into trouble. I nearly flipped ours of a flat road once while cutting up fun.

      1. This. While it may not cause damage, having good battery management is to battery longevity. An increased discharge rate can shorten the battery life. Telsa spends a huge amount of engineering effort on battery management to ensure long life for the battery. The fact that many tesla batteries, if not the vast majority, have lasted well longer than 100K miles. My 2013 Model S still has about 97% of its original capacity.

        1. It’s not the miles that kill the battery in a Tesla. If you have 300 miles of range, 100k miles is just over 300 full charge cycles. Common consumer grade lithium cells should last three times that.

          In electric cars, time and temperature is what really kills the battery. The state of health of a lithium cell just sitting in the car is pretty much inversely proportional to time x temperature x state of charge. That’s why manufacturers generally give you a warranty of 8 years OR 160k miles – they expect the battery to begin showing age after about 8 years. Whether it actually lasts for 10, 12, 15 years depends on how you keep it.

          1. Also mind that the battery is over-provisioned and limited by design, so seeing 97% of range is not a sign that the battery is still almost as good as it came from the factory. If the original design capacity had +15% extra, that’s actually 84% SoH.

            How lithium cells age, the capacity curve starts to take a steep nose-dive somewhere between 80% and 60%, so you may already be at the edge of that cliff.

          2. The difficulty in defining what is the full capacity of a lithium cell is in the fact that there is no such thing as a “full” lithium cell. You can keep charging it to higher and higher voltages and get more and more capacity out of it, but doing so causes exponentially more damage to the cell with each charging cycle – to the point of setting it on fire.

            The same thing goes for what is understood as “empty”. The lower you discharge, the more range you get, but it runs for fewer cycles. Narrowing the voltage range to gain more charge cycles loses range, but increases the apparent cycle life of the battery.

            Tesla, being cost-conscious, will optimize the battery chemistry for greater capacity at the cost of cycle endurance, since this hardly matters for the intended use. They simply hide this fact by limiting the BMS to use a narrower span of the available SoC and increasing the span as more cycles are used, so it looks like the battery is at or near 100% state of health for longer.

            All the EV manufacturers do some variation of this – the original GM Volt EV for example had a 16 kWh battery and only used 9 kWh of it for a whopping 78% over-provision, which allowed them to use some pretty crummy cheap batteries and still make the promised mileage. However, it means that when the battery does start to show age, it is REALLY going down because it’s right at the limits where lithium cells would be considered end-of-life.

          3. >Pulling more amps from the battery will heat the battery up.

            This is true. It also applies to rapid charging. However, the effect is short and pales in comparison to keeping the car outside in the sun every day vs. keeping it in a cooled garage.

        2. “Telsa spends a huge amount of engineering effort on battery management to ensure long life for the battery.”

          Yes, and that huge amount of engineering is “lie about its actual capacity.” The batteries start out with effectively greater than 100% capacity, but the system only uses 100%. So you don’t see any degradation for a long time because it’s just hidden from you.

    1. Electric motors usually have high overload tolerances. +40% is not that much as long as it isn’t sustained power. The limit as you point out is overheating, and usually the motor management will deal with that by limiting power.

      1. Yeah, but over some time the system the motor is part of probably will have some complaint that the power output was increased by nearly half over its design specs. Kind of like when I walk by a parked car with massive rims and you can look inside and see that the brake calipers are stock. Classic mistake

        1. Sure. Thermal stresses accumulate, and the insulation in the motor will experience higher heat loads before the thermal cutoffs can operate. This will not help the lifespan of the motor, but it won’t be such a dramatic problem either, considering it only applies to short bursts of acceleration.

        2. You don’t floor the accelerator under normal use every time you go from the stop lights. Marginally more power will be applied to the electric motor in normal operation, but this is likely still within the original specs of the motor.

          1. One foreseeable problem would be that this mod changes the power balance between the engine and the electric motor. It throws the engine load map off, so the combustion pressures and revs will be wrong and the efficiency of the engine under load goes down, hurting your fuel mileage.

            Or it may be that it pushes the engine to a better spot on the map, and the original compromise was made for other reasons, such as for conserving the battery if that is the limiting factor.

    2. The electric motor in an Insight is integrated into the flywheel; it’s between the engine and the transaxle. Since they are a series hybrid not a parallel hybrid (The electric motor cannot drive the car independent of the engine) they will chug along happily with the hybrid system disconnected; Honda was even nice enough to put a normal starter in there so the engine could be cranked even if the hybrid system has a fault. Buddy of mine had a coworker with one with almost 400,000 miles on it. Hybrid battery was dead and the transmission was missing 5th gear and he still got 40 mpg.

  3. “engines that can’t be fixed on one’s own due to the proprietary computer control systems”

    I remember a while back reading some articles here on HaD. One was about a guy who printed an adapter and installed a lawnmower carburetor in a car. I think there was also one where a guy designed his own carburetor from scratch. Or maybe I found that in the aftermath. Because that article had a youtube video which lead to others which lead to others, not unlike Wikipedia.

    But anyway, there were videos where people were explaining (much over my head) the engineering of a catalytic converter.

    Sorry.. but the illusion that automotive complexity is a new thing was shattered forever. Clearly it’s always been more complex and computerized. It’s just that the computers ran on fluids, air and pressure rather than electrons and voltage. And they were always black boxes to the mere mortals that worked on them. Working on a car was always just swapping out black box computers.

    1. The big difference between a mechanical system and an electronic one is the mechanical one is obvious to the observer and practically impossible to hide the functionality. Where the electronics is a board covered in chips that may or may not have any labels on them at all, that could do almost anything.

      While you can trace the PCB and gain some idea of how stuff connects as soon as it gets more complex than this PBC is basically just a reference example of some common buck/boost chip feeding another common example micro etc it becomes a game of wild guesses and probing, logic capture, quite possible decapping and high power magnification to figure out how the electronics work. With a mechanical system everything about how it works is quite easy to identify as its not all happening in the magic smoke contained within black blobs of epoxy. And for good measure if the company can make the part in a mass production setting its almost certainly possible for you or your local machine shop to make it in a relatively simple home workshop if you care to put in a bit of effort, money and time – where (practically) nobody has a home silicon fab…

        1. You want to buy me one sure – Not a brand I’d heard of but a quick look makes it seem like they are very vanilla watch mechanisms in fancy cases… Expensive and small/delicate doesn’t make it complex to understand – I’d hope as a they are a fancier brand they have nice to have features for great lifespan and accuracy etc and great surface finishes but ultimately other than a few really weird outlier watch mechanisms there isn’t much difference between a watch and a larger clock.

          1. The devil may be in the details.

            For example, the shape of the escapement teeth may be due to some complex mathematical formula that was found to improve the efficiency and let the watch run twice as long. Just looking at it may not reveal what that shape needs to be, so replacing a broken escapement wheel with something you made yourself to “look the part” or “that ought to work” may not result in the same performance.

            The basic principle of the device may be simple to understand, but the details of the design escape people who are not intimately familiar with the principles involved.

          2. Or, as I was watching a youtube video of a camera repair shop, the guy they were interviewing said something along the lines of, “Any engineer can repair a camera with spare parts in hand, but without the original repair guide they’re liable to break more than they fix and bodge it up. This makes the camera work, but it becomes unrepairable for the next guy.”

          3. Dude I never said the fix was trivial – just that is much more possible to look at understand how it works, which does then lead to being easier to replicate a mechanical part than an epoxy blob cluster with no documentation – even decapped with how common FPGA and microprocessor type ‘universal’ chips are you can’t figure out how it all works without the code as well.

            As seen in things like the reconstruction Antikythera mechanisms you don’t even need the whole thing in working order when you examine it if you care to put the effort in to it as each part that survives is very apparently an x toothed gear etc – it doesn’t look identical to the rest of the a,b, and c toothed gear but for the magic smoke contained inside.

        2. Pretty simple actually.

          Super expensive and fancy obsolete watch movement in jeweled case gets rich F-ers laid by hos. Costs mega bucks. Chinese knockoff works as well in dark clubs. Steel belted radial condoms recommended.

          Now you understand how a Patek Phillipe works.

      1. I have never really seen physical engines as anything simple and can’t work on them. But electric is easy to understand. I would not be able to repair a gasoline engine that won’t start, but I might be able to diagnose a faulty electric car and change the components.

        1. The problem there I’d suggest is just you don’t understand the principles of ICE enough, or are just too scared to play with what is probably the second and maybe the most expensive thing you own – though these days the engine is more likely to have en electrical gremlin than a mechanical one anyway… So you should be able to fix them by your argument that you could fix an EV by swapping parts. And it would be massively safer to play with a ICE with an electrical gremlin than the EV – those battery are really really darn scary if you don’t know what you are doing, but the engine management stuff and sensors of an ICE are all nice safe low voltage.

          The actual function of each bit in an ICE isn’t hard to work out – look at a flappy bit behind an air filter, may not know what it is called but have a good idea of what it does, in an old purely mechanical engine bay follow the Bowden cable that actuates it and you can understand that whole section… Take the head off and look at pushrods and valves, have a look at a camshaft, see the timing belt keeping everything in sync etc – one bit moves, pushes another and how the whole thing interacts is right there in for anybody with the patience to see. So take it apart with some care, maybe take notes if you don’t have the right service manual or understanding and you can fix anything. Not the case with electronics, especially with electronics that make efforts not to be understood with no labels on the chips or the silkscreen etc. You look at it and can’t even be sure in this era of many many layered boards if that pin is connected to anything at all. So something goes wrong and all you can do is remove the whole lumps and replace them if the documentation isn’t there to debug your way to which one of these chips let out the magic smoke (assuming there are replacement boards or chips available too – and often there doesn’t seem to be except as salvage – can’t make your own the way its plausible to do so with a mechanical system (except perhaps the mad fool working on silicon fab is their garage)).

          1. Another thing is that ICEs and mechanical things will often work in failure mode. They’re robust like that. It’s a good thing – and a bad thing.

            I had a 1980’s car where half the vacuum hoses were rotted away or missing and the carb dash pot was completely dry, but it would still work with slight adjustments. The throttle response was off (I didn’t know what it was supposed to be like!), it didn’t quite have the power (as if I had a dyno to confirm!), the ignition advance was off at high revs (but I didn’t know that!), but it started and ran “fine”. Probably the only reason it did run was a piece of debris stuck in some vacuum port in the carb so it would get the mixture in the right ballpark.

            Same thing with my old moped. It was finicky to the point that I had to stick a piece of hose in the air intake to constrict flow. I didn’t know that the carb was undersized and having that extra vacuum would make it pull more fuel through the jet – otherwise it would run lean and not start. 15 year old me couldn’t explain why it works like that – just that it did. I was running it “on the choke” all the time, and it ran perfectly – in a condition that was definitely wrong for the machine.

            Without knowing how the thing was supposed to work, you may not get the thing fixed right just by “having a look and think”, as I didn’t. It’s still in failure mode – you just bypassed the problem by luck or accident, and you may not be any wiser of it.

          2. Indeed Dude, but if you understand the principles properly and have any idea at all how it is supposed to perform you should be able to figure it out with a mechanical system. From the point it works you just keep fiddling till it runs as well as it can/you care to bother.
            Something you can’t really do with electronics without the documentation and software at all in many cases – without the firmware that FPGA is just a highly processed lump of expensive rock.

      2. >the mechanical one is obvious to the observer and practically impossible to hide the functionality

        It seems you’ve never tried to service an early 90’s Ford carburetor with all the emission controls, pre-heating and multi-venturi throttles and recirculation…

      3. over a decade in automotive electronics, I can mostly assure you that what is on that PCB is a set of supper common parts using the stock reference designs with maybe a little passive glue between or to tweak available options.

        Its automotive, no one wants to be all rouge hacker and get their asses handed to them over a recall cause they used some junk no name chip pushed a little too far. The documentation trail goes all the way back to the sand the stuff was made from

        1. Also, because they’re using the cheapest suppliers, nobody wants to do anything clever. Conservative designs with wide tolerances means it will still work when all the parts are out of spec.

      4. I’d argue that it’s pretty difficult to understand a carburettor just by looking at it (not least because there’s internal air/fuel passages that aren’t obvious to an external look). On the other hand, a fuel injector is conceptually simple, ‘put electricity in, get fuel out’.

    2. Semantic sorcery. I can work on large, mechanical parts, but I can’t do much with a chip under a black blob of epoxy. There are talented people who can tease out some esoteric secrets from the blob, but even these are fairly limited. Any mechanic should be able to understand how an engine works, that’s in the scope of their job. reverse-engineering computers (designed to be hostile towards understanding, whereas the engine is designed to be understood) (usually) is not.

      1. >Any mechanic should be able to understand how an engine works, that’s in the scope of their job.

        There’s so many pitfalls in that statement. If you don’t know the design, you can apply many plausible but wrong assumptions and get it kinda-sorta working, but on wrong principles that deviate from the original point. Then the next guy comes along and tries to bodge around your bodge, and it just won’t work.

  4. This seems highly illegal and dangerous to human safety. Plus, risky for the equipment.
    I get goosebumps when I read a sentence saying “the only other change is to upgrade the 100 A fuse near the battery for a larger size”, and you should too, there are so many things wrong with it.
    I would not even do it with my electric bike.

      1. Depends on what the design tolerances are for the wire.

        You don’t design the cabling to only just handle what the fuse is sized for, because you’d lose too much power in the cable. The way fuses work, the cable has to tolerate much more current than the fuse in order for the fuse to work in a short circuit – otherwise the cable can limit the circuit and not blow the fuse.

        The fuse is there to protect the weaker points, such as the battery itself.

  5. <>

    I owned a 47 Willys jeep. It held no mysteries. At one time or another I held every part in my hands and connected every wire.

    Things started getting mysterious with the advent of the automatic transmission and multi-jet carburetors.

    Given the complexity of projects that show up on HaD, it always surprises me that there’s not more (or maybe any) open source ECU projects out there.

    1. There’s a few out there – Megasquirt probably being the most well known DIY option (source available but not open licensed). There’s truly Open Source options out there like Speeduino and RusEFI as well – likely others but those are the ones I know of.

      1. It’s an analogue computer that meters out and mixes a certain amount of fuel, depending on the airflow through it and various other inputs (accelerator pedal movements, idle mixture settings, manifold vacuum etc.). Basically magic.

    2. The ammount of complexity that is built in a ECU anfäd the ammount of calibrationnand tuning that is needed to get a decently running engine nowadays is not replacable by an open source project. Additionally there are legal constraints that do not allow tampering with the certified settings (even though there is a huge aftermarket of ECU/Chip tuning – mainly illegal).
      your 47 jeep would run on a variety of hydrocarbons, produce a ton of soot and dangerous gases, has an efficiency that is ok for war time under the circumstances, lasts a human lifetime or more, makes a fat noise that will wake the whole neighborhood, has besides brakes no features that are asociable with the term safetx, and is probably too slow to drive safely on a highway.

      If you want to roll an ECU on your own, start with an engine from the late 80’s, that is managable.

    3. About the same story over here. I miss purely mechanical vehicles that didn’t have a TV-sized touchscreen for a dashboard. They were better and that is actually a matter of fact, not opinion. Get these kids off my lawn!

  6. Fuses on circuit boards generally protect equipment.

    Fuses in the wiring are sized to (Only!) protect the wiring from getting more power than it can handle, thus preventing fire. It has nothing to do with what is hooked up at the end of the wire. To put it simply, bigger fuse needs bigger wire.

    1. If they are able to solder a resistor in parallel of the shunt resistor instead of changing them, I guess they’ll also solder a 2.5mm2 wire in parallel to the actual cabling and hoping for the best. Hopefully, this kind of mods don’t last long, the wire will burn its insulation, touch some ground and then burn the battery since the fuse will no longer protect it. Problem solved!

    2. It depends on the application. In some cases the fuse is there to protect the electronics and not the wire.

      In a house wiring, you’re correct, but there are also mandatory safety factors for the wiring size so that the fuse will reliably blow before the cable even begins to get hot. Fuses also don’t act instantly, so you may exceed the rated current by 100% for brief periods of time up to 10 seconds, depending on the fuse.

      The EU rating for 1.3 mm^2 wire is 10 Amps. Hence you need a 10 Amp fuse for it. The resistance of such a copper wire is 13 milli-ohms per meter, which causes a power loss of only 1.3 Watts per meter at the rated current. (P=RI^2) This will not cause significant heating of the cable even if it was embedded in a wall, which is the point of such ratings. Doubling the current to 20 A causes about 5 Watts of heating, and you need tens of watts per meter before it gets dangerously hot quickly, so you can “safely” run twice the current – just not legally so.

      1. Note that a 20 Amp fuse may require 40 amps to blow “instantly”, and if it’s a slow fuse your heating power would be about 21 Watts per meter for 10 seconds. That gets you into the danger zone if the fuse doesn’t work as intended, which is why you shouldn’t do that.

      2. In this case the fuse is there to prevent fire in case the electronics fail.
        The wire will be sized for performance purposes. The fuse is probably sized to be as small (read:cheap) as possible

        1. Besides, fuses don’t come cheaper when smaller in rating. It’s comparatively harder to make the smaller fuse because the operating tolerances will be smaller as well, so it has to be made “better”.

      3. Sometimes you get trouble with long wires, maybe some contact resistances, and devices that draw more current when the voltage is lower. There may be warnings not to chain extension cords, and of course if the voltage drops out of spec at the end under load you shouldn’t use it, but you have to know that’s what is happening of course.

  7. I don’t doubt that this works, but there’s no way 100Amps is going through that shunt resistor.

    It would be interesting to know how this really works instead of the (at least I think) incorrect explanation.

    I’m willing to learn something new in case I’m misunderstanding this.

    1. You are partly wrong, 40 % more power means 40 % less distance when at full throttle, but most people don’t drive at full throttle. This mod won’t really increase the power consumption when driving normally but it will increase the maximum acceleration and maximum power used when accelerating. So assuming you drive it the same before and after the mod the range will not change, but if you are modding it in the first place you will probably accelerate more aggressively and hence will probably end up with a shorter range.

      1. Driving slow cars fast is much more fun than driving fast cars slow.

        A Honda Insight is as slow a car as exists. A Honda 600N could outrun it.

        The great thing about 600Ns? You drive them at full throttle, barely keep up, assuming you drive well, right gear etc.
        I should get another, but they’re insanely priced for what they are. Like bugs.

    2. I have a ICE car with more power, through increased maximum boost from the turbos. It’s still just as economical as it was before, depending on how it is driven. Maybe even better now.
      With more torque at lower rpm, it could be more efficient.
      It didn’t come from the factory this way due to turbo lifespan. And probably because BMW wanted a bigger performance gap between a 335 and an M3

      This being a series hybrid, may also result in better fuel economy due to less load on the ICE.

      Everything is a trade off. You could argue that increasing the value of this resistor will make your car last longer. It probably will. It will probably make your MPG worse too

  8. Safety is important, but those here readily forget that the major corporate car makers have given us vehicles that catch on fire overnight while sitting in your garage whether ICE or EV.

    As an American and heavily pro Bill of Rights, there are way too many regulations on personal vehicles that the consumer is being forced to pay for whether they want it or not.

    1. ” …there are way too many regulations on personal vehicles that the consumer is being forced to pay for whether they want it or not.”

      That (unfortunately) is not going to change. As politicians ‘see’ fossil fuel automobiles as part of the air pollution problem, restrictions will become more strict until automakers just cannot meet new standards and throw-up their hands in frustration – alternative powered vehicles will be the only option in the future. Electric (Inc. solar), hydrogen (Inc. fuel cell) are the contenders for the near-term.

      But, do not forget that tax revenues must the replaced: reduction in petrol-fueled vehicles significantly impact tax collections. The taxman will not be cheated out of a penny. Plug-in vehicles will likely require separate metering to manage non-residential wattage pricing.

      Potentially, the most damning aspect to computerized vehicles will be laws that demand that all vehicles be equipped with real-time data telemetry and vehicle-to-debit transactions for every infraction of “the rules of the road.”

      1. The tax question is insidious because it will require at least some form of mileage monitoring, which implies always on GPS tracking and reporting to authorities. Otherwise people will cheat the “black box” and start screwing with the odometers. The alternative is fixed yearly taxes which will be too onerous for poor people and unfair for people who drive less.

        Fortunately, there’s some signs of backpedaling in the EU with politicians getting shaky feet over the 2030-35 ICE engine bans. The voters really don’t like it, so the industry has had some success lobbying for e-fuels (synthetic gasoline) to get a pass.

        1. In NZ we have road user charges for diesel vehicles, where there is no road tax

          Tampering with your odometer is illegal. Just like swapping your petrol engine with a diesel one without registering it as such.

          It seems to work ok

          There are plans to add road user changes to EVs. Eventually maybe all car, with taxes removed from petrol to capture hybrid road usage too.

          1. Something being illegal has no bearing on the point – just getting caught doing it has.

            How do you do that for odometers depends on how they plan to implement and inspect them. Regular odometers in cars are routinely faked by people selling used import cars that have no local inspection records, so no paper trail to show what the reading should be.

          2. One effect of “do not tamper” laws is that parts of your car become unrepairable as you’re not allowed to touch them – only approved technicians would then be allowed to fix whatever is broken with the engine management unit that holds the odometer.

            Which is a boon for the manufacturers looking to implement planned obsolescence. Integrate all the important electronics with the system that holds the legally required data, and whoops it’s John Deere all over.

      2. >restrictions will become more strict until automakers just cannot meet new standards

        With the EU emission/economy standards, they already can’t. They’ve been passing the regulations by cheating, and the politicians have allowed this because voters like stricter emission standards (“they’re doing something about it”). At the same time, the voters don’t like more expensive, less powerful and smaller cars, so the politicians have allowed the industry to cheat for decades in order to keep up appearances. The limit has been reached where they can no longer continue cheating, or making up new regulations, without admitting to the fraud.

    2. Yes, there are too many regulations, you’re right. You can’t even legally build a reasonably sized truck anymore. I just have to take care of my Ford Ranger until judgement day. People will whine about how all the new trucks are the size of tanks and filled with unaffordable luxury features, yet do they have any idea what CAFE regulations are? Or that they voted for them? No. They think some vague group of rednecks is to blame, but it’s the opposite.

      1. Winning comment of the thread. Go look up Eric Peter’s Autos who has commented on this very thing. The problem is that getting lead out of gasoline has now become ban everything and the consumer is paying the price.

        I’m all for a clean environment and have worked with chemicals in labs that do need to be disposed of properly, but yes, people are totally ignorant of how bad these regulations are and that ignorant ideologues with little science or engineering education or ability or making this stuff up.

    1. I don’t think that’s what they’re telling you.

      As I read it, “[…] lets the computer sense the amount of current being drawn from the hybrid battery and delivered to the electric motor” means that the added resistor is there to trick the sensing mechanism/method into thinking less current is flowing than is actually flowing.

      The motor controller would increase the *sensed* current until it matches the target. As a result, the actual current is higher than what the measuring device is reporting.

  9. Consider: you don’t floor the accelerator under normal use every time you go from the stop lights. Marginally more power will be applied to the electric motor in normal operation, but this is likely still within the original specs of the motor.

  10. Wow, some of the comments here seem really out of character for HaD. Honda massively overbuilt the Insight, as it was the first modern production hybrid. The entire drive train, motor, inverter, DC-DC, etc. I’m sure some of you will be horrified to learn I own an Insight with both the 40% current hack and 60S 10KWh lithium conversion that raises the nominal voltage from 144v to 222v! It turns the car into a plugin hybrid that I can control with either the gas pedal or a thumb stick. I can get 300+mpg for 30-40 miles on the electric motor, or burn the tires with 21KW of instant torque plus 67hp from the engine. The Insight is a fun car to modify with an amazing community of enthusiasts. Only filling the tank every 1500 miles is nice too.

    1. 21 kW is 28 hp. Pick a unit.

      88 hp…Must scream.
      Putting the Geo Metros in the rear-view, for sure. Running with mini-vans soon, if you keep up the tuning. Dare to dream.

      Bet the NHRA tech guys want you to put in a cage and a chute.
      But that would ruin the collectability. On a sweet car like that, you want matching #s and factory paint.

  11. You guy’s countries are soft. There’s more than one boat car legally on the road where I live in Florida USA. A 4 horsepower boost on a 20 year old electric car wouldn’t raise an eyebrow

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