I just read about this in R&T (I subscribe to GRM too), looks like an interesting implementation of an "electric turbo".
The motor/generator replaces the flywheel and the engine ECU doesn't need to know it's there. Good for 150 hp boost.
Right now they only do Porsches and it costs $75,000. Has anyone else tried this before?
Looks similar to what Mercedes is using behind their new inline-six.
That's just another electric hybrid set up. And if you want it to work the most effectively, the engine does need to know it's there.
Given the cost and the benefit, you will start seeing items like this popping up on a lot of new cars. Which means people will try to adapt them to older cars for various reasons.
For 150hp, you will need some serious batteries to make it work. Ok, by "serious" they are nothing compared to what a typical hybrid has. But it's very much not the standard 12V battery seen in a car. 150hp is just under 112 kW, or 111,900 W. Many starter-gen sets run at 48 V, which would be over 200A. So I'm guessing that P runs that at a more typical hybrid voltage of over 400V, which keeps the current way down, increasing the efficiency of the system.
That is pretty much how the original 2000 Honda Insight Hybrid worked. $75k is rather expensive, does it include the batteries, charger, etc?
nimblemotorsports said:That is pretty much how the original 2000 Honda Insight Hybrid worked.
The only thing it doesn't have is a way to keep all the valves from opening so that all "engine braking" is done with the motor/generator.
Given that this is the whole general idea behind hybrids - recoup braking energy for use later - I don't see this doing all that much for fuel economy relative to a properly engineered hybrid. And if it doesn't benefit economy, well... even for Porsches, you can buy 150hp conventionally for less than $75k, I'd think.
With the size of their battery pack, that 150hp is going to last single digit seconds. Good thing you can only floor a modern Porsche for single digit seconds on the street anyway.
It's a one trick pony kind of implementation. When people start adapting something more like the belt-drive mild hybrid systems in place of regular alternators etc and more of the features that go along with them, it'll be more interesting to me personally.
Vigo said:With the size of their battery pack, that 150hp is going to last single digit seconds. Good thing you can only floor a modern Porsche for single digit seconds on the street anyway.
It's a one trick pony kind of implementation. When people start adapting something more like the belt-drive mild hybrid systems in place of regular alternators etc and more of the features that go along with them, it'll be more interesting to me personally.
I'm not sure if I really see the major difference between a belt driven vs. direct drive system- really, the difference is do you mount it like an alternator or like the starter? Power wise, the direct drive can put more out, given there is a limit on the belt- but that will take a lot of power output to make it.
One interesting tidbit I've heard in development, the belt driven ones don't generate enough torque to spin a cold engine (below 80F), so you need a starter anyway.
In terms of the one trick- it's also the trick that has the most potential- recovering energy that would normally go to the brakes. No, you can't drive on a battery charge, but it's the biggest carrot for the lowest cost in terms of hybrid improvement. IMHO, that's why Honda chose that path with the Insight in the first place. But since the world was more about hybrid enthusiasts, the Prius won out.
The thing is- for that kind of system, what voltage do you run it at? The higher = more efficiency and more cost. 48V appears to the the starting point.
alfadriver said:In terms of the one trick- it's also the trick that has the most potential- recovering energy that would normally go to the brakes. No, you can't drive on a battery charge, but it's the biggest carrot for the lowest cost in terms of hybrid improvement. IMHO, that's why Honda chose that path with the Insight in the first place. But since the world was more about hybrid enthusiasts, the Prius won out.
Some interesting anecdotes about that.
Honda's first gen Insight required VTEC so that the engine would contribute nothing to engine braking. The Insight's VTEC kept the intake valves from opening in the first place. So it was kind of like GM's DoD except it applied to all of the cylinders, and it didn't break.
Had a customer with an Insight with a failing IMA battery so he had us do some procedure to disconnect it. Even running gasoline-only, every time he came in for service his fuel economy minder was over 60mpg. So the Insight really didn't NEED hybrid tech to get good economy, since it had a slippery shape plus no weight plus an efficiency-driven engine design. The IMA was only there to add power to cover for the fact that it had a 1.3l engine with an effiency-driven design.
Having experienced both... the Prius is an awesome hybrid. The Insight (first gen) is a gimmicky CRX HF.
In reply to Knurled. :
That's actually a good point- where the electric system is there to make up for the lack of expected performance. Sort of like a turbo, but one where some of the energy is gotten from waste energy.
and it's interesting that the Insight didn't get much better...
Yea, a way to keep the valves open (or closed actually) would greatly increase the amount of recovery a system can do- but given the location of this P car system- you could easily decouple the engine and just shut if off, and let the system get driven by the transmission. Well, I say easily in theory- it would be a complicated system, for sure. But the cost of an extra clutch is cheaper than most valve deactivation systems (other than the whole engine on/off system that Honda can do).
In reply to alfadriver :
I think the best add on hybrid system would be like a Gear Vendors overdrive, where it sits in between the tranamission and driveshaft. The problem lies with integrating everything with the engine management.
Integration is where the true wizardry lies.
When I win the lotto I’m totally doing this to my 996 and Boxster. Then I’m going to go find fast cars and make them cry.
Isn’t FCA’s “light hybrid” kind of similar? I rented a 2020 Ram 1500 with the Hemi and a 48 volt battery pack connected to a motor/generator that was mechanically connected via belt to the crankshaft. And of course it does regenerative braking. According to FCA, when all the planets align it boosts the torque output at the crank to 540. That truck would scoot. Brake pedal felt slightly wonky in light braking conditions.
They show classic 911s on their page but their only examples are newer ones, so I'm wondering how a clutch and pressure plate would work with this.
They're not trying to turn a 911 into a 918 or a Prius. If it was a lot cheaper and as bolt on as they claim the system would be an alternative to a turbo kit.
For $75K you can buy a really nice car and build a REALLY nice motor that puts out way more than 150 hp extra.
I'm not sure if I really see the major difference between a belt driven vs. direct drive system- really, the difference is do you mount it like an alternator or like the starter?
The difference is that it's easier. Adding some kind of big spacer between the engine and trans has some fairly serious mechanical side effects in most cars, whereas attaching something slightly larger in place of the alternator is pretty easy in some cases, like the FCA vehicles where it's right on top with plenty of hood clearance. I'm just approaching this in terms of some aftermarket company making some kind of bolt-on mild hybrid system.
Yeah, with the belt drive you're limited to how much torque the stock belt can accept. I don't have a number for that but i do know i've seen numerous cars where a seized accessory pulley kept the engine from cranking, so it's at least more than the starter itself is capable of (1-3hp big whoop, but a fair bit of torque!). Stock belt-driven mild hybrid systems usually use a larger (wider) belt so those are actually up a notch or two from that. There's a lot of belt capacity info to be gleaned by reading into the issues people have driving superchargers. Wider belts, more idler pullies to increase belt wrap, etc. Some of them are putting probably 70-100hp across a 'regular old serpentine belt'. Another benefit of putting something on the belt drive is you get the torque multiplication from the pulley ratio.
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