Five years ago, Stellantis killed the SRT division responsible for so many heroic vehicles. Anything with a Hellcat engine, the Viper SRT-10, the Ram SRT-10, the Neon SRT-4, the list goes on. Midway through last year, it brought it back into a brave new era. The Dodge Charger no longer offers a V8, the Challenger doesn’t exist anymore, and at the time, you couldn’t even get a Ram 1500 with a V8. It’s all part of a larger shake-up, and now we’re seeing early results of SRT’s latest go-fast endeavors: Giving a pair of turbochargers their own electric supercharger.
When turbocharging became mainstream again in the 2000s, we ended up with vehicles that weren’t the laggy, rip-snorting, fire-breathing turbo models of old because that sort of turbocharger sizing just wasn’t going to replace the low-down torque of a larger-displacement naturally aspirated engine. Some enthusiasts think it’s cool for forced induction to finally have enough exhaust pressure at 3,000 RPM and deliver a shove in the back comparable to being rear-ended by a TGV. The average consumer doesn’t want that at all, so we got all these turbocharged cars that fall flat on their face in the upper rev range like an early fuel-injected pushrod V8.
Obviously, larger turbochargers can prevent the power band from rolling over, but then you introduce that lag the typical driver doesn’t like. While automakers have tried various solutions in the past, ranging from twin-scroll turbochargers to variable geometry turbochargers to electrified turbochargers, they all have their trade-offs. Limited efficacy or cost and complexity, usually.
While not the first of its sort, Volvo’s twincharged T6 four-cylinder engine took another variable mainstream: Parasitic drag. To combat lag, the Swedish marque decided that a belt-driven supercharger would be the best bet for feeding the engine compressed air at low RPMs, with a turbocharger doing the work higher up in the rev range and a bypass valve managing the handoff. It works, but there are some efficiency trade-offs. That supercharger takes engine power to turn, and that’s not an ideal compromise.
Genesis took things one step further by eliminating the belt. The G90 and GV80 Coupe are available with a twin-turbocharged 3.5-liter V6 that also has a 48-volt electric supercharger. Drawing from power harvested by a starter-generator and stored in a battery, the 48-volt electric supercharger compresses air to feed the intake until the turbochargers wake up. But wait, what if instead of feeding the throttle body directly, the 48-volt electric supercharger fed the turbochargers instead?
That’s exactly how Stellantis’ eBoost Air system works. It uses fresh air compressed by the electric supercharger to spool the turbochargers from their compressor sides. In essence, it’s compound-charging until the valve in the intake ducting opens once the turbochargers can take it away on their own. So what are the upsides here? Well, the system’s targeting quicker spool on larger turbochargers, it doesn’t rob any power from the crankshaft, and all of the charge cooling can be done downstream of the turbochargers.
Bolted to a high-output Hurricane three-liter inline-six installed on a Jeep Grand Cherokee, Stellantis claims the eBoost Air system is capable of “virtually eliminating turbo lag.” That’s all well and good on stock turbochargers, but I’m excited to see what it could do when paired with larger units.
Still, as far as ways to combat lag go, eBoost Air has a certain simplicity to it. One electric valve like a throttle body, a few pipes, a relatively cheap 48-volt supercharger, and that’s about it. No need to draw air through a charge cooler or feed it through a second charge cooler, no need for additional water-to-air plumbing. While we don’t yet know how or if SRT actually plans on using this tech in a production car, they probably wouldn’t be showing it off if they weren’t at least considering it. Either way, it feels wild as all hell, feeding boost into turbochargers to make boost.
Top graphic images: SRT
So hear me out, what if engineers were to further reduce the turbo lag by connecting the electric supercharger directly to the engine. Or even better, add it directly to the drive! You could build it right into the transmission for instant torque and power!!! If they put it in a Jeep, they could do a play on words about 4×4 and call it 4 EXtra amazing! (*editor’s note I have a neighbor who drives her plug in Pacifica a few days a month between dealer visits; and a fried with a 4xe that doesnt park it inside very often…).
As is implied by the headline, this sounds like a very American way to make a hybrid worse so it will sell to American truck people who are indoctrinated to hate hybrids.
Although I like the idead, why doesn’t it make more sense to just develop a hybrid turbo that uses an electric motor to spin it until the turbine can take over?
I feel like I have read about such a turbo recently. Did someone else patent it and Dodge can’t/won’t license the tech?
An electric/exhaust hybrid turbo seems like the simpler and better solution. It even eliminates the valves from the situation. I will not call them simple, because I am aware of the dual turbo RX7 and its love of failing.
See the 911 Turbo S review a few articles down, has exactly what you’re describing.
Thank you. I knew I read it recently.
That’s what I was thinking. E-turbo with extra steps.
Anybody else remember growing up in the F&F era, and the guys with bodykits on automatic civics would install an ‘electric turbo’ and they were pretty much all proven to be BS?
I swear I even remember reading articles in magazines debunking these things saying the physics don’t work out, and it would never be a viable way to add power…
The electric turbos of that time were literally just bilge blowers for boats.
Buy at full retail, slap a sticker on it and sell it on ebay for three times as much (four times if you include a switch and a few zip ties to make it a kit).
I thought the idea of being American car is about having large displacement engine with comfy seats/suspension setup for long straight cruise
I’m afraid that died with the Ford Crown Victoria. Torque, comfy seating, smooth suspension: pick two.
This makes a lot of sense. I hope other builders develop it too.
DANGER TO MANIFOLD
I’ve thought about a motor/generator connected to the shaft of a conventional turbo. You could use it to spin the turbo up instantly and eliminate the wastegate setup entirely. Just use the motor to control shaft speed and sip on off the excess energy in the process. Use this as power to spin up the turbo during transients.
It’s funny you say that
Seems like that could be really useful in F1….
Sounds a bit like the roadkill experiments with Yard blowers connected to a gennie to make boost.
My favorite is still the Boost Caboose.
At one point I had it mathed out that I could use a 15-20 hp mower engine and a Buick M90 supercharger to boost our Lemons car, but it sadly never came to be.
I have a mower in that range. You’d need another fuel tank to keep that thing running for a whole race.
Stellantis hasn’t even mastered 12 volt electrical systems and now they are playing around with a 48 volt system. I see no issues with this since they did so well with the 4xe electrical systems.
the E-Torque in the rams is 48V. Is it without problems? no, and they are doing away with it because of some of those issues, but I imagine they are better able to understand it than others just based upon experience and what not.
Given their somewhat tenuous relationship with quality, I’m not convinced that experience factors very heavily in Sellantis’s design process. It definitely seem to be more of a ‘Hold my beer and let’s try this!’ design philosophy which then has whatever good sense was left in it cut out by corporate bean counters.
Stellantis hasn’t even mastered PAINT yet
Well they have a firm grip on rust, or vice versa.
Hell, my recent experience suggests that they may have never mastered 6v systems, or else the previous owner messed something up when he retrofitted an aux jack
Maybe it’ll wind up better since they are already using such thin strands of wiring
“Feels American As Hell”
As in, copying something foreign companies have done for many many years, likely making it exponentially worse?
Yep, very american indeed xD
It’s a similar idea, but the implementation is very different than what I’ve seen before.
Mercedes M139 and M256 use the electric supercharger to provide direct boost.
Porsche’s “e-Turbo” is probably the closest, but it uses a electric motor mounted directly to the turbo (between the compressor and turbine) to keep the turbo spinning.
Calling this “copying” would be like saying BMW’s ShiftCam and Honda’s VTEC are the same thing. They attempt to solve the same problem, but they are different.
There’s more than one way to skin a cat…
American car makers have invented and introduced plenty of important technologies that became mainstream. Of course other countries invented stuff as well, but people who think that US cars are just big engines with ancient technology have no idea what they’re talking about (I’m not American btw).
Hasn’t Audi been selling these for a decade?
Dear Lord! In my reading here today, I have been rear-ended by a 747 AND a TGV on launch. What’s next? A Saturn V?
A JATO bottle should do the trick.-
Too bad they only have an ON switch.
It’s so close in idea to being effectively an MGU-H from F1 but so far off in execution.. (the MGU-H was probably my favorite piece of automotive tech of my lifetime)
It just feels like this version would have a ton of conversion loss (generate electricity, spin blower with electricity, spool turbo with blower charge). With every step incurring fairly significant losses.
Not really? The supercharger doesn’t seem like it’s meant to run full-time
I’m not really following. The Genesis system (which the article says is similar to the SRT one) uses a serpentine belt-driven starter/generator, which incurrs paracitic loss to generate power for the supercharger. It feels a lot more efficient (and probably robust) to just electrically drive the compressor side of the turbo while using the turbine side to generate the electricity. This has the additional benefit of almost eliminating wasted boost and harvesting basically all of it’s energy from waste energy (exhaust) instead of from the crank (ie. a belt-driven starter/generator).
I’m assuming it all comes down to cost, although I do question how much cheaper developing and building an electric supercharger and coupling it with a turbo along with all the associated components mentioned in the article would be compared to a MGU-H system which would also have the benefit of simplified packaging…
More likely, it all comes down to finding a solution that isn’t already covered by someone else’s patents.
Not THAT is a reason I hadn’t considered…
American as hell, lolol. In addition to every other mention in the comments, JLR P400 ingenium engines have used an electric supercharger since 2020.
Clearly this is MOPAR still taking inspiration from RoadKill. They started with leaf blowers, then they saw the potential in electrifying those leaf blowers, then the decided bolt those fuckers onto turbos
Boy, they really like spending on warranty repairs, don’t they?
not really, they are kind of taking over where Hyundai left off with regard to the customer experience for warranty repairs.
Audi did this years ago.
And is it just me or does it seem like this site getting kickbacks on the patriotism and Stellantis articles lately?
I’ve vowed not to buy another Dodge/Chrysler/Ram product so I’m only reading these articles for fun. And there are a lot because Stellantis is one of the few companies delivering fun ideas/concepts when everyone else is building boring cars successfully or just scrambling to fix recalls.
Granted, they are going to fail at 90% of the shit they are seemingly throwing at the wall in an effort to make things stick, but in the meantime it’s entertaining! Like in the way you can’t look away from a car crash….
idk, I might agree a few years back with the hurricane and complete revamp of the Charger, but now they just seem like they’re scrambling to shove an antiquated HEMI into everything so they can shout about having a V8 at bald eagles like they’re on a rural talk-AM radio channel arguing politics.
And then they can reprogram the Fratzonic exhaust to also generate the supercharger whine. Might have to put another speaker under the hood.
I’m no engineer, but this seems like a horribly inefficient way to transfer power. Might as well go full Rube Goldberg.
Seems horribly inefficient… yes, that’s why the title claims it “Feels American As Hell”, right?
No, the American way is “inefficient, but dang it it just works”. This feels more like something out of the reject pile of German or Japanese engineering. Complicated, delicate, AND inefficient!
So this means the Hurricane 6 fits in a Grand Cherokee?
Also I’d be more interested in this system if anyone else other than Stellantis was developing it.
Yes, I have zero confidence in their ability to make this durable, same with the twin turbo I6s in general. If it was Toyota 15 years ago, maybe.
Doesn’t the much-maligned 4cyl C63 do this?
I wonder if this plays into the plans reported a few weeks ago, for a 600hp Charger for the 60th anniversary. Larger turbo + this setup should make that number attainable.
*Looks at the 911 Turbo hybrid turbo system and looks at this*
I think there’s a way to cut out a lot of extra parts in the anti- turbo-lag category that SRT isn’t considering
Each of the 911s turbos probably costs more than an entire Hurricane engine. This seems technologically much simpler than trying to get an electric motor to survive in the middle of a turbocharger.
Plus, seems a lot easier to add to an existing engine platform.
I know this is counter-intuitive, but it was really fun the first time I drove a MazdaSpeed Miata with its little turbo that spooled up with just enough lag to disconnect the press of the foot to the feeling in your butt. Can’t help but grin wide as you got pushed back in your seat a bit. A real “I have got to get me one of these!” moment; and I did.
I later did some go-fast intake and fuel control mods to reduce the lag (thank you Flying Miata!), but that slightly delayed boost was missed, just a little, when it was gone.
Later, another Miata I had with a supercharger also didn’t come with the delayed boost, and though I knew off the line it was quick, I also missed, just a little, that kick in the pants that the delayed boost gave you.
Turbo lag isn’t great for performance when “I want to go NOW!” from idle or low speed, but it definitely has the giggle-inducing quality of your car saying to you, “oh, you want to play?”. In my Fiesta ST it the lag makes you want to keep the car on boil and it’s more fun than a barrel of monkeys when you drive with vigor, but good lord, it sure is slow until it wakes up. It’s funny how Camrys can easily outrun me from a light, but I can push a lot of higher class performance cars hard in the twisties.
My old Sonic had similar giggling inducing boost curves. Stay out of boost and it was just a slow commuter penalty box, rev past 3k and OMG what are we doing, we’re gonna die! I tuned it and did a few supporting mods to double the boost in the thing, which really made it hilarious by 4K. I left the exhaust stock, which kept it from attracting too much attention.
I had a tuned Cruze that did the same thing. Flip the cruise control on and it was stock. Flip the cruise off and be ready. 3rd gear was a lot of fun. It pulled hard. No mods besides the tune. Fun car, I kind of wish I still had it.
I originally had that tune, but upgraded to a new tune from Bad News Racing after I ported the intake manifold, and added a K&N Cold Air Intake. It also had No Lift Shift, but that never quite worked right, I did remove the speed limiter, and tested that once. That limiter was there for a reason, anything above 120 was beyond the aerodynamic limits of the car.
I miss the power, but not the terribly uncomfortable seats and quickly failing interior plastics.
Agreed, we often make things less fun as we pursue more raw speed. I find myself preferring the fun side of the equation more and more these days.
This was announced on the day after I went on a shallow dive for engines with both a supercharger and a turbocharger, like my Detroit 8V92T. Wikipedia has a good amount of these engines under a subheading
https://en.wikipedia.org/wiki/Twincharger#Applications
All I really learned is that I would gladly trade my Wanderlodge for a Nissan Micra Superturbo.
You have a Blue Bird Wanderlodge motorhome with a big ol’ 8V92T? Does Mercedes Streeter know? Does it have a sub-10s 0-60 time?
I like the odds of Mercedes both seeing my comment and also just happening to have a spare twincharged supermini to trade.
My dad had an IH truck/tractor pulling a total of 80,000 pounds GVW with an 8V71. The famous 318. He was so happy when he sold it and got a Kenworth with a 350 Cummins.
No one ever wanted to sit within 20 feet of those Detroits for more than 10 minutes.
Mine’s 30 feet behind me swaddled in sound insulation, but it did startle me the first few times I went under an overpass. I kept looking for a motorcycle with an open pipe hauling ass up my port gunwale.
Volvo has entered the conversation.
HONK HONK
Honk!
I have to admit being clueless about the ‘honk’ reference. Is that a Wanderlodge thing, or a motorhome thing in general?
The Super Turbo makes a “honk” kind of noise under hard throttle when handing off between the SC and turbo. Mighty Car Mods had a series on the Nissan March Super Turbo about five years ago. Lots of “honk” involved.
Now I really want one!
So, the aftermarket electric turbos from ebay were actually onto something?
Yeah, but only when paired with a Fuel Shark and an intake Tornado.
In theory yes, in practice absolutely not.