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Comment by olivermarks | Hacker News Reader

One thing to bear in mind when that converting ice vehicles to electric is that they are constructed with a vertical firewall between engine and driver with lots of protection around location of fuel tanks and fuel lines. EV's are typically designed with a horizontal fire wall to protect the occupants from the batteries beneath them, which become unstable in a violent impact and often burn repeatedly. The centre of gravity in an ICE vehicle is very different to an EV. It is therefore arguably better to build some sort of EV kit car with a crate motor than to attempt to convert an ICE monocoque imo

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We're (mostly) talking about classic car conversions for something like this. Safety is way down the list of concerns. If you prioritize safety at all, you won't even consider riding in a classic vehicle.

I don't see how the nuances of a battery fire vs. much more likely ICE fire would enter into any reasonable consideration.

Exactly. This is for converting that 1971 VW “Thing” that is a deathtrap just standing still. You would drive in a relaxed manner it from your garage to the nearest coffee & cars meetup on Sunday morning, then back again.

Nobody is buying these with the intention of building an electric hyper-car to use at the track.

Why wouldn't something like this crate engine be great for a Prius? The Prius has a 90hp ICE. Replace that with a 110hp crate electric and now you have more power in a 100% electric vehicle.

Doubt the extra horsepower will get you much gain once you add batteries

Not this particular motor, no. But you can bet people will be swapping these into racecars all the same. I'd love an electric powered track car.

Fires in car crashes are actually quite rare. That's very much a Hollywood-ism.

Yes they’re rare but they still do happen. Next time you’re making a long drive on the freeway, watch the edges of the road for blackened pavement indicating a car caught fire and burned to the ground in that spot. It might be more often than you think.

EV fires are common. https://en.wikipedia.org/wiki/Plug-in_electric_vehicle_fire_...

Most of the time a crate engine enters the equation there is some sort of hideously unsafe car waiting for it. Its safe to assume that if you are the kind of person installing a crate engine you have some sort of idea of what you are doing, and are capable of taking informed risks.

Your reasoning assumes people don't skip steps in the process of learning things. There are cliches to support my case. "Only knows enough to be dangerous" "More dollars than sense"

That itself is dangerous. You're basically discouraging someone from offering advice to the general public because you think the knowledge is generally known, but that's just not the case.

I have a general idea of what I'm doing but reading that comment changed my perspective of what is and isn't dangerous in a car and those dangers shift from ICE to electric.

Frankly, I'm glad he opened my mind to the ideas.

>That itself is dangerous. You're basically discouraging someone from offering advice to the general public because you think the knowledge is generally known, but that's just not the case.

And if you don't discourage it all discourse gets drowned out into a bunch of "hurr durr don't forget your jack stands" type virtue signaling (in the technical sense, not the politically loaded sense) about safety and you get Reddit. You can't please everyone.

IIRC the earlier work on roll-overs made the point that all cars have a resonate roll-over frequency that plays a part when drivers over correct a swerve. I wonder if anyone is taking a new look at that isdue. Also, whdn a bunch of combustion engines get displaced, what is therd to do with them beyond recycling the metal? Looks like the cost of these freed-up motors is about to drop. Motor futures; shorting anyone?

Reminder: Kevin Hart is suing the builder of his Hellcat 700HP Plymouth Barracuda.

Not to be rude, but you would have to be real thick to not understand how unsafe that car would be. I know it's a harsh thing to say, especially because Kevin Hart was seriously injured. Still, when you take risks, sometimes it doesn't work out.

One of my college professors said there are things that are intrinsically unsafe. Where layered defenses don't buy you much. A fuckup means a high risk of being injured.

Sadly yes.

There's a reason that e.g. Shelby Cobras are so rare. Very easy to spin out a short wheelbase car with a V8.

https://en.wikipedia.org/wiki/AC_Cobra

It is a disgrace that Hart is suing the car builder.He had someone build a high performance show car and then allowed a friend to crash it. He is now wrecking everyone's right to modify and build cars because of his own stupidity.

>The driver, Jared Black, lost control of Hart's 1970 Plymouth 'Cuda while driving with Hart and Black's fiancé, Rebecca Broxterman, in the back seat. The car plowed through a wooden fence and careened down an embankment, where it came to rest in a heap.

Reminder: dont let your cool friends drive your race car. This is how Paul Walker died.

Paul’s friend was driving his own car, I forget where I heard an in depth about it but supposedly the tires on those cars went bad fast, and it was one of the first items they were driving it. Irresponsible, but in those conditions that car had essentially no grip, combined with a car that was legendarily known for being very difficult to drive on atleast 8+ year tires was a recipe for disaster

The more grip the tires have, the shorter their life.

The less grip your tires have, the shorter your life.

My understanding is that it wasn't a treadwear issue, but more like dryrot..the car had been stored for a long time.

I'm not sure how long tires last in storage, but if they're X years old they can look and feel perfectly new, but not be safe anymore.

That was the issue, the car had very little miles, but were stock tires

Basically, replace tires if they are 5 years old on cars like that. Age is a big problem.

Generally, 5-8 years. UV exposure makes a big difference.

I had a car in storage one time and the tires looked great. I took it in for inspection and the guy was like "sorry man these tires are over 5 years old, I can't pass this". At first I was really mad, and then calmed down and realized that there was probably a reason why, so I went ahead and got new tires.

You are right, they were co-owners of the garage.

I am a mature and experienced driver and I drove FWD and AWD cars all of my life. On several occasions i stopped myself from buying a powerful RWD sports car .... just because of all the cases where (even experienced) drivers spin out and crash while taking "high speed" turns in poor traction conditions. I know that ill most likely push my car and not being able to control it - freaks me out! I cant even imagine giving someone else to drive a 700HP monster (with me not being in full control)!!!

The next car this (and other) shops build (if they survive the law suit) will come with a stack of "release of liability" documents for the buyer to sign. I 1000% guarantee that.

Its stupid on their part that they sold the car to him without release from any potential liability if he crashes the car or injures himself and others, like in this case.

In a high performance car, even lifting the throttle in a turn can put it into a spin.

Wait until you hear about motorcycles...

https://youtu.be/3sniigpXfAY?t=140

That guy was just being stubborn. He had long since dumped the bike low side and tried to correct by locking the handlebars all the way left.

The rider wasn't being "stubborn".

It's a right hand turn and "locking the handlebars all the way to the left" wasn't trying to correct the "dumping" of the bike.

Locking the handlebars all the way left would hopefully have ensured the bike went down, stayed down and not sat back up again thus causing the "tank slapper". When you ride a bike, especially a motorbike you counter intuitively "steer left" to turn right, and vice versa.

Former sports bike rider here...until I bit the big green banana.

I was driving through the desert in my truck. I took a tight turn, probably a little too fast for my truck but it worked out. The driver in the performance car behind me wound up flying off the road. Because it was flat terrain he was fine and back on the road shortly. But I always wondered why my truck took the turn alright, and he had what could have turned in to a nasty crash. I guess the lesson here is, make sure to keep your tire tread in check.

I highly doubt it's tire tread if it was dry weather.

Turn-in is actually noticeably improved by lower tire tread on tires (as long as your tires are still roadworthy and the road is dry).

If you take a look at one of the most popular "sticky" tires for autocross, it almost looks like the tread has completely worn away on a normal tire: https://www.tirerack.com/images/videos/video_images_758x426/...

More likely they tried to get into the throttle during the turn at the wrong place, or tried to brake during the turn when caught off-guard, both of which would upset the balance of the car and send you off the road.

Traction control (or intentional chassis/suspension design) might have saved them from oversteering (spinning out towards the road), but not been able to prevent them from going off the road

Probably panicked and locked up the brakes. Most cars (even sports cars) are set up to understeer unless really provoked, on the basis that a frontal crash is safer than hitting something sideways.

Speculation, but could have been: Going into the corner too hot, coming out of the corner too hot (throttle induced oversteer), or just not knowing how to drive...

I was once at an "open track day", and this group of kids brought a Nissan GTR and a Skyline. They couldn't drive these cars, there was a Miata out there that they couldn't keep up with. I never actually saw them out on the track, so all I have is second hand reports via stories that were making the rounds of the pits, but I do know they didn't stay very long.

Sports cars usually have stiff sway bars, which are generally better for high grip situations. Your truck, and rally cars will generally have less or no sway bars because in a hard off road corner, weight will transfer to the outside wheels which helps them bite into the ground and keep you on track. A car with stiff sway bars and suspension will slide out horizontally because the whole car stays much flatter in the corner.

Highly doubtful, he probably hit the accelerator in the turn and overdid it. There's no way your pickup out handled a performance car on blacktop.

> Its stupid on their part that they sold the car to him without release from any potential liability if he crashes the car or injures himself and others, like in this case.

It boggles me that anyone would have any expectation that the seller of a high performance car would be liable for the driver crashing it. It’s not like they didn’t know it was a beast of a car. What happened to personal responsibility?

We live in a world of "terms of conditions" and "disclosures" and "terms of use".

Even this simple purely informational use only website HN has a 10 pages list of "terms & conditions": https://www.ycombinator.com/legal/

Any performance car builder should have one too.

The machinist who built my engine told me the only reason he was doing it was because I was over 40.

I assume “money” was also a reason?

No. Though he knew I could pay for it because the parts I brought in were expensive ones, and of course he wouldn't give me the result if I didn't pay.

I assure you there there are good machinists out there who will gladly take an 18 year old's money, so he isn't really helping anyone except getting some virtue signaling out of it.

I'm sure there are. My machinist did a good job, the engine is a bad mofo sleeper and just what I wanted :-)

Lol really? Guess what Kevin, building a fast car and not learning how to drive a fast car has consequences. I have a a 650 HP mustang, one of the first things I did was take classes on how to handle high horsepower vehicles. What an idiot.

The CG isn't likely to be considered in the sort of vehicles this crate engine is going into, it isn't usually even from the factory. This is a 100HP motor, most cars with a 100HP motor are far from a 50/50 weight distribution. :-)

I'm more concerned with integration with safety features like airbags. I'd love to do an EV conversion of some fairly pedestrian car with my daughter for her first car, but I'm likely to take a fairly pedestrian donor car, and even a couple grand is going to get a car with airbags that need to integrate with the various sensors (including, as I understand it, ECU and engine sensors) to say when to fire.

>This is a 100HP motor, most cars with a 100HP motor are far from a 50/50 weight distribution.

Honda Prelude and similiar have ~100hp and pretty decent weight distribution.

Which Honda Prelude? The H22A engine puts out more like 200HP. Not at all in this class. Grassroots Motorsports corner weighed a Honda Civic Si, still performance oriented, still way over the 100HP, and found 62% front loading. The Honda site lists the 2011 Civic Coupe as 60/40 and 140HP.

I imagine a whole ecosystem around the conversion process, with modular components designed to replace the functions not directly provided by the engine.

However airbags and similar systems may be too risky litigation-wise.

How is that any different than adding a fuel cell to an ice which has similar constraints? Couldn't an aftermarket battery pack be made that has all the requisite fire protection built into the case (again, similar to fuel cells)?

Or have a battery that's shaped like a fuel tank? Maybe you won't get the same range as battery all over but it's prob enough for most people?

You're probably get an awful range out of a fuel tank shaped and sized battery pack.

Not sure why you're being downvoted. In the future when battery energy densities are a multiple of current gen we'll definitely have gas tank form factor batteries for restomods.

Today the range would be pretty bad though, but probably fine for a classic car grocery getter or trailer/show queen.

I think the bigger concern is fire protection, which is already a solved problem with fuel cells. Shouldn't be too different for batteries.

I suspect the aversion to a more blocky shape (higher volume/surface-area ratio), has to do with heat dissipation, which if I recall correctly, improves with surface-area.

EDIT: hence the flatter/thinner batteries we see in EVs.

That actually mostly doesn't matter for most batteries. Most EV batteries are actively cooled/heated with fluid moving inside. So the heat dissipation occurs in the radiator for the battery, not at the surface of the battery. We see flat batteries because sticking the battery at the bottom of the car helps with weight distribution and handling.

That's actually something I'm working on right now. I'm trying to convert a Mazda RX-8, which has a weird gas tank that goes up and over the drive shaft. I think I can get about half my battery back where the gas tank was (which is right under the back seats).

I'm not sure where all the rest are going to go, but probably most will be in the engine compartment somewhere.

I could also use the space where the muffler was, but I'd have to make sure there's enough weight in the front of the car to offset it.

> adding a fuel cell to an ice

For anyone as confused as I was: https://en.wikipedia.org/wiki/Fuel_tank#Racing_fuel_cell

It's one of my pet peeves that in the racing world "fuel cell" means "hardened fuel tank" instead of "solid state fuel oxidising power generator".

Particularly as fuel cell engines have been researched.

For electric conversions, Lithium iron phosphate batteries are popular in part because they're less likely to catch on fire if you puncture them, short them, overcharge them, or otherwise abuse them.

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