Inside GM's State-of-the-Art Powertrain Engineering Center

Inside GM’s State-of-the-Art Powertrain Engineering Center
Photos courtesy of General Motors

The engines in today’s GM pickup trucks have never faced stiffer competition, but there’s not much that can be done about their design or performance except to look at the future, which GM is actively shaping inside its state-of-the-art Powertrain Engineering Development Center in Pontiac, Mich.

The $463 million benchmark facility opened in early 2008 next to the company’s Global Powertrain headquarters. It’s the crown jewel of more than 30 years of planning and restructuring.

Until the 1980s, GM’s brand divisions were managed as a confederacy. Chevrolet, Cadillac, Buick, Oldsmobile and Pontiac all maintained separate headquarters and engineering staffs that only came together on the bottom line of the company’s financial statements. It wasn’t unusual for similar vehicles, like the Chevrolet Camaro and Pontiac Firebird, to use V-8 or V-6 powertrains with designs and parts that didn’t share much in common except for their intended purpose and maybe a few bolts.

Industry rivalry changed all of that. As Japanese cars became popular and Ford and Chrysler grabbed market share from GM with new products, GM consolidated divisional engineering teams into shared resources that would design fewer engines at less cost with increased reliability.

In 1984, five engineering development teams became two with the creation of the Buick-Oldsmobile-Cadillac and Chevrolet-Pontiac-GM of Canada Powertrain divisions. In 1990, they merged into a single entity, General Motors Engine Division. In 1991, GMED and Hydra-Matic transmission groups were reorganized to create GM Powertrain. Later that year, the Central Foundry Division and Advance Engineering were merged into the division. In 1997, the formation of a GM global powertrain organization was announced, encompassing all of GM's powertrain engineering and manufacturing activities outside of North America.

Dyno cells are built to test everything from a standalone engine to a full powertrain. Here, a 5.3-liter V-8 engine is tested with its transmission.

Over time, multiple GM powertrain development centers around Detroit were phased out. GM opened the doors to the Powertrain Engineering Development Center in 2008, on the site of the old Pontiac Motor Division.

But it wasn’t just GM’s disjointed powertrain organization that changed. Three decades ago, computers were quickly finding their way into automotive development. They became invaluable because engineers could save time (and money) by designing and modifying parts on a screen instead of by hand.

Computer aided design was soon supplemented with computer simulation, which tested parts performance virtually before a physical copy was ever fabricated and tested in the real world. Modeling and simulation became more sophisticated as the lessons learned from the previous generation of car or truck were applied to the next generation.

GM slowly transformed its powertrain development process from one that designed and improved engines and transmissions based on real-world trial and error over thousands of vehicles and miles into a modern methodology that has more in common with software development than old-school powertrain hacking.

“If you can move work from the road to the lab, that’s fast. If you can move from the lab to math (data), that’s even faster. That’s our philosophy,” said Radu Theyyunni, GM powertrain engineering group manager for system design and analysis. In GM engineering speak, it’s called RLM: road to lab to math.


Theyyunni’s team is brought into a vehicle’s development very early in the lifecycle to help determine its performance and fuel economy targets. If a pickup truck requires a new powertrain, the mill’s displacement, architecture (diesel, gas, direct injection, turbocharged), transmission and axle ratio are estimated, and software is used to calculate the engine’s bore, stroke and crank size to model its power and torque characteristics. All of this happens before a single engine drawing or design has been created. This is where the rubber meets the road for Theyyunni and his number crunchers.

“Our goal is to use simulation methods to make sure that the first time we [physically] build a powertrain, it’s the optimal design,” Theyyunni said. “If you look back to before 2000, we’d design stuff and test it. It was a design and test philosophy. If a part broke, we’d go back and redesign and test it. There would be a postmortem where we’d be asked why [it] broke, and we [could provide a reason] but we weren’t driving the design. It was more like a support role, and each build could take six to eight months. What we’ve done in the last 10 years [is] move to math-based development.”

Today, powertrain analysis and design is done in short cycles, using powerful computers to develop a new engine.

Friction, temperature, emissions, fuel economy and other key traits are modeled and simulated multiple times to optimize component performance long before the first physical part of an engine is tested on a dyno.

“It’s like a zipper,” Theyyunni said. “Now, we do hundreds of [analysis and design] iterations [using computers] depending on what the component is. Then we test in a virtual validation using characteristics modeled in math, such as the ports [which determine how well an engine can breathe], block size and seal and gasket sizing. Each part in the [engine’s] bill of design and materials uses [math-based] rule sets that we’ve developed over time that have become our best practices. That’s what we use to create our simulations. Once you build your hardware, it’s too late to make a [design] change.

Engines are quickly moved in and out of dyno cells on pallets that float on a cushion of air like an air hockey puck.

“Back in the old days, we could always tell you why something broke,” Theyyunni said. “But today when I tell you up front it’s going to break here, it’s a whole new level of responsibility. [Our role] is more challenging, but it’s also more fun.”

The lessons learned from this iterative approach have helped GM improve each new generation of engines and have shortened the time required to develop them. Novel data and lessons learned from real-world testing that don’t agree with existing simulations are turned into new math-based rules that are factored into the next round of virtual validation testing.

“That’s where continuous improvement comes from, and it’s how we get better over time,” Theyyunni said. “Analysis, design and testing are linked together. Some of the designs are baked into our software so if a designer tries to build something out of whack, he’ll get a warning message that he’s violating his part guidelines.”

Depending on complexity and scope, some engine activity modeling can require up to three days of non-stop computing time using more than 100 CPUs to render three minutes of enhanced video footage that can be reviewed and understood by a powertrain engineer. That’s still shorter than what used to require weeks or months testing an actual engine on a dyno, and failing an engine in a computer is cheaper than failing an engine on a dyno.

Part of Theyyunni’s recent modeling efforts were the analysis and design of GM’s next-generation small-block V-8 that will help power all-new Chevy and GMC pickups by 2013 (which we expect will be 2014 model year trucks). The engines will feature aluminum engine blocks, direct injection and an advanced combustion system.

“We looked at hundreds of combinations of ports, chambers, cam designs and injector designs,” Theyyunni said.

In a non-fueled test cell, a transmission is coupled to an electric motor that stands-in for a gasoline-powered engine.

The latest version of the 6.6-liter Duramax V-8 diesel for the 2011 Chevy and GMC heavy-duty pickups required more than 500 piston bowl designs – a special shape carved in the top of the piston that helps control the way air swirls above the piston during combustion – before the optimal shape was created and rendered in metal.

Finally, after all the analysis, design and simulation are complete, a cross-functional group of engineers and managers reviews the results. If approved, the virtual engine becomes reality within walking distance of the computers it was designed on, and then it’s on to dyno testing or shipped to GM’s Milford Proving Grounds to be installed in a vehicle.

The 450,000-square-foot Powertrain Engineering and Development Center has two test wings that house 85 dynamometer test cells. It also has 100 powertrain component test stands and a powertrain engineering factory where prototype engines — from gasoline to electric — are built and assembled.

Steve Nash, the center’s engineering development manager, walked us around.

In engine dyno cells, test engines are subjected to different loads and environmental conditions using various calibrations designed to help the engine adapt to workload and climate while ensuring the engine doesn’t break. Valvetrain performance is also measured and checked against design specs. What used to require intrusive sensors installed on valves – which added mass and changed a valve’s shape – to measure engine timing is now done passively with lasers that return significantly more accurate data.

To help reduce the costs and risks associated with hot and cold weather simulations, rather than heat or cool entire dyno cells, environment boxes are lowered into place around engines or entire powertrains to simulate temperature extremes, from minus 40 degrees to more than 130 degrees.

Thermal oxidizers destroy at least 96 percent of carbon monoxide produced by test engines before the exhaust is released.

Non-firing dyno cells are used to spin up and test transmissions without the need for a conventional engine. Small low-inertia AC electric motors that can be programmed to simulate the firing pulses of almost any kind of internal combustion engine, from four-cylinder to V-10, are mated directly to the experimental gearbox’s torque converter.

“In the old days, we used to always have to have an engine and transmission to do dyno work,” Nash said. “The prime mover was the engine, and the transmission factory would always say we have to wait for the engine before we could test the transmission. In this facility, we’ve decoupled that. We don’t need an engine to start transmission calibrations and development. It’s all about being fast to market.”

Dynoed transmissions can also be paired with test or production rear differentials to simulate drivetrain load. To speed up the powertrain test process even more, the entire rig — with or without an engine — can be tilted dynamically in a way that simulates driving on an actual road or highway to start dialing in transmission calibrations before a future engine is ever fabricated and paired with the gearbox.

“Any road course we have at Milford can be simulated on our tilt stands, including compound angles [which simulate stopping on an angle] and up to 1.3 g [through a turn],” Nash said. “If there’s an issue with a customer’s engine on a specific road course, we can map [the road], bring [the model] in here and rerun it.”

In 63 percent calibration dyno cells, the entire powertrain and drivetrain is brought together physically for the first time. Calibration data from the test is provided to vehicle engineers at Milford, where they can use that information to get a jump-start on making further adjustments and changes in test vehicles running in the real world.

Another innovative technique used to reduce testing time is the plug-and-play movement of engines into dyno cells on air-floated pallets. All of the cables and instrumentation needed to record data during dyno testing that used to be part of the test chamber is rigged to the pallet and engine before the entire unit enters a cell. Changeover procedures that used to require a full day connecting an engine to sensors and fluid feed lines can be now be completed in as little as 20 minutes. This also allows the dyno chamber to have maximum uptime for improved engine testing productivity, and fewer dyno chambers are needed to manage the work. A single person can move the air-cushioned pallets that tip the scales at 3,000 pounds like a giant air hockey puck.

Powertrain engineers and dyno technicians sit side-by-side outside each test cell during testing.

“We always want to make sure our test cells are running,” Nash said. “And we never have to change the test cell if an engineer comes along and says they need to collect more data. Before, they would screw up our [dyno cell] template. Now, the test cell always stays the same.”

Innovative ideas have also been implemented to manage emergencies. Instead of using carbon dioxide to put out a fire, high-pressure water mist is used to smother flames so rescuers or injured people don’t risk suffocation. Dyno chamber roofs are also engineered at an angle with blow-off panels in the event of an explosion.

All of the engine exhaust created during dyno testing is captured on site and funneled to four large thermal oxidizers that scrub and clean the exhaust to remove up to 98 percent of harmful carbon monoxide and soot before the exhaust is released into the air.

Up to 250,000 gallons of fuel is stored on site, and it takes one large refueling tank truck a day, like you’d see at a gas station, to keep things running. There are 27 fuel types, including all gasoline octanes, diesel, biodiesel, ethanol, methanol, compressed natural gas and liquefied petroleum gas.

All of this adds up to one of the most advanced powertrain facilities on the planet that’s designing and creating GM’s future, one engine at a time.


I can't wait to see what GM churns out for the next gen trucks, esp considering the innovations by Ford, technology encourages better technology, we could be talking power AND MPG's. awesome

Great work General Motors Corporation!

This is American engineering at it's finest! This is why American O.H.V./pushrod motors can still compete, and beat, overly sophisticated O.H.C. motors.

Great story! Thanks!

We will have to just wait...............wait......................wait and see.

You mean to tell me they do not have an aluminum block or direct injection in their pickup engines? It's 2011...

My 1997 Tacoma had those features without the $463 million facility, hmmm...

All of that and they still build pushrod's...

nice write up mike intresting stuff, wonder what the other fuel types are

@ Oxi

You're 1997 Tacoma does not have direct injection. To date no production Toyotas have direct injection including the Tacoma and Tundra.

Some Lexus engines have direct injection.

@ Oxi

Sorry partner, your 97 Tacoma doesn't have direct injection. Check your facts before you bash, then we might take you seriously.

@Bob M.
While Oxi's 1997 Tacoma does not have direct injection from factory, there are numerous production Toyota vehicles that do, although to my knowledge they're all sold outside of USA and Canada. They are called diesels...

@ Tony,

I understand there are diesel Toyota's that utilize direct injection. I meant gasoline engines in the North America market. That was my error for not clarifying

OXI my 2011 Chevy has an aluminun block and with the pushrods, or cam in block, as they call it now, they can use MDS to shut half the cly. off, for more mpg, the Hemi, and the 5.3 have it toyota NO, and they also have variable cam timing also, and I'm not sure but, I bet the Hemi and all Chevy small block V-8's weigh less than the 5.7, maybe even the 4.6 &4.7 toyotas too. I know from experience that they get better mpg than any toyota V-8, the 4.7 in the 1st gen tundra at work get awful milage, I could hall the same load in my Dakota V-8 with less effort and still get better mpg, and the V-8 in the Dakota? 4.7 aluminum block an heads w/ohc. to boot! You realy getting to be obnOXIous, if you don't have anthing nice or informative to say shut your pie hole!

I am excited about the next generation pickups from GM. I only wish I didn't have to wait until 2013 to drive one. What ever GM comes out with, I have no doubt it will be the standard that other trucks will be measured against. I also wonder what the next great innovation GM comes out with that nobody else has thought of. I guess we will just have to wait for now. I love new innovation, just look how far cars and trucks have come over the last 20 years.

Heck, just look how far, snowmobiles, motorcycles, waverunners have come over the last 20 years.

@Bob Personally I think I'd love to see GM come out with some decent power (no one really needs more than like 400 lb-ft in a half ton) but crazy good mpg, like 26-30 mpg or something along those lines. I think if GM leaves the power wars for the HD segment and focuses on good power and better economy, they could crush ford, this coming from a guy who's about to take the plunge on a 2011 f-150

That is some good stuff to hear about. I want Mike's job

i agree they should come out with something that gets 25 to 30 MPG's and forget about the HP wars if they could do something like that, we shall see

Cool stuff. Would've been nice if they threw us a bone on some new engine ideas. It's been a long time coming GM.

I still wonder if the reverse flow 4.5L dmax was a problematic design. All that heat concentrated in the center/top of the engine and being so far away from air flow. Maybe it solved some things but created other issues?

The article reads like an AVL commercial. They're the vendor for all that neat dyno cell equipment. IIRC, they have some Horiba (schenk-pegasus) stuff up there too, but AVL got much of the business. I have seen plenty of quick-change engine carts, but the floating carts they have are slick. Anyone know how they're powered?

@Oxi ('s expense): Not only didn't his '97Tacoma Not have direct injection, Toyota first rolled out DI in 1998, and it was 2005 before the 1st Toyota in the US got DI (Lexus GS300). Further, the RZ and VZ engines used in Toyota trucks bofore 2005 had IRON blocks and alloy heads. ( They're tough motors, but they aren't what Oxi claims.
/piling on


government motors will ALWAYS be behind the LEADER, FORD. FORD will ALWAYS be the KING of trucks.

It is nice to see some news from GMC.
I am looking foreward to seeing what they come up with.

They refine computer modeling based on prior real world data.I do get the impression that they are "stuck" on the use of pushrod engines. (not saying that is a bad thing)

How do they think outside of the box?
Would they consider moving away from pushrod engines?

It is too bad that they are being so tight lipped about what they will release in 2013.

@Oxi... your '97 Tacoma.. if you ever had one.. came with an IRON block. The 3.4L V6 and the little I4 were NEVER produced in a aluminum block for the Taco.

Go back in your hole TROLL!!!

@ Mike,

Great article! It's great to see GM working on some new fuel efficient engines. Can wait to see what they come up with. Would love to see them keep to similar hp and torque numbers as the 5.3 but with much higher mpg.

What do you hear from Toyota? When will they step up to direct injection and more fuel efficient engines in the Tacoma and Tundra? I believe the Tundra is out a ways like 2013 or 2014, but what about the Tacoma. It's crazy to me that the compact and midsize truck aren't much better with fuel economy than the full size trucks.


GM had a V-8 aluminum engine in 1960,it was later used by LandRover until several years ago !

GM has had an aluminum engine in its trucks for a while now...

Chrysler had a couple aluminum engines since the early 90's and a Aluminum V-8 in 99.

But for reliabilty and longer life cast iron is the best,many aluminum engines cannot be rebuilt ! mostly import aluminum engines are problematic !

Toyota's Tacoma aluminum 6 cyl uses more fuel than a pushrod V-8,so I dont see an advantage in anything Toyota has !

There is nothing wrong with a pushrod engine,the worlds most powerful engine is a pushrod (Chrysler 426 Hemi 10,000+h.p used by Toyota,Ford and GM in top fuel today)

Toyota still used point ignitions and carbs when the American manufacturers had electronic ignition and fuel injection.

I will give Toyota this,they are the number 1 company for random excelleration,rusting frames,cracking side glass,cracking tailgates,bad welds,bad engines,bad cams,oil sludge,falling out transmissions,rusting floors,rocker panels..and recalls out the tail pipe and its owners are Kool-Aid chuggers !!

Instead of SAVING money on fuel, I'd rather WASTE money replacing rear tires, GM, my current rear tires are in pretty rough shape for being less than a year old, lets see if we can only get 3 months out of the set on my 2014! Aggresive goal...

Funny,I see Chevy add on t.v with the Heavy Duty trucks and GM is comparing its new Diesel with Dodge's old 650 torque Diesel and bragging about it....that is putting egg all over GM's face...Dodge now has 800 ft lbs of torque,so the new GM diesel obviously cant beat the new H.O Cummins RAM,they had to rush out propaganda adds with the lower torque,older Dodge Cummins engine..Still , GM/Ford/Chrysler is better than any unreliable Toyota lol !!

You should know morpar doesn't rule, that 800 foot pounds of torque doesn't mean dodge will beat GM'S 765 foot pounds of torque. Ford's powerstroke has 800 pounds of torque and it didn't help them beat the mighty duramax diesel. I am sure will run another shootout with Dodge's high output cummins diesel and they will post the results. GM didn't rush anything and Dodge only upped their cummins engine because GM and ford were leaving them far behind. Rumble in the rockies didn't even include a Dodge truck because it exceeded the gross vehicle weight ratings and it was deemed unsafe to do so.

So if I were you mopar doesn't rule, I wouldn't run your mouth about 800 pounds of torque because that doesn't mean the Dodge will be the first up the hill. It may even finish in 3rd place.

Next HD Shootout (we're calling it the Grudge Match) is in July. Yes, we'll have the HO Cummins.

@Mike Levine,

I am looking forward to the No Holds Barred Grudge Match.

mike levine why don't you test regular cab long bed single rear wheel 2wds for your next HD shoot out so we can see the most that these trucks can pull and the fastest they can accelerate. Using crew cab long bed dual rear wheel 4wds waters down performance.

You should have a regular cab short bed 4wd off road package or regular cab short bed 2wd work truck test with Vortec V8, Hemi V8, I-Force V8, Coyote V8, and Ecoboost V6.

Nobody buys regular cabs anymore. They went out of style in the early 90's.

@ Josh - regular cab trucks are a dying breed. I rarely ever see one other than fleet trucks.
A "Grudge match" is an appropriate term. Regardless of who wins someone will hold a grudge ;)

@Toyota lol - I find it silly to brag about the "(Chrysler 426 Hemi 10,000+h.p used by Toyota,Ford and GM in top fuel today).
The rules state that each manufacture is stuck with the hemi design.
That is like saying Harley V-twins are the best motors out there ,but you are only allowed to race at the AHDRA (All Harley Drag Racing Association) events with a Harley.

Engines do not get MPG.
Engines do get BSFC.

So GM's new pushrod engines will be 2 or 3 valves per cylinder?
1 or 2 spark plugs.
Direct injection
Cam-in-cam VVT (an upgrade on VCT)

Will GM have their 8 speed automatic ready for the 2013 model year?

Really, there hasn't been much substantial new engine design ideas from any manufacturer for a long time.

A few years back it was the electronic valve/camless engine designs but not much talk about that anymore.

How about a split cycle engine being able to improve fuel efficiency by 50%:


You can have any beer here as long as it is a Corona - Dom Toretto, F&F

@ Frank - as long as your buying ;)

GM- Got Ecoboost?


Aw, to bad........

Ford is winning.............. :)

Every Tacoma I have owned has NOT had a distributor!

2. 3RZ–FE Engine
The DIS (Direct Ignition System) has been adopted.

The DIS (Direct Ignition System) contributes to the powerful high output by providing a powerful spark to the engine. The ignition system is the same as in the 3RZ–FE engine of the ’97 Toyota Tacoma.

The 2.7L 3RZ-FE 4 cylinder is found in both 2WD and 4WD models. This dual overhead cam engine offers 150 HP and 177 lb-ft of torque. The 3RZ also sports a timing chain setup. 1995.5 and 1996 year models use a distributor type ignition system. 1997 and later models use a distributorless ignition system (DIS). DIS replaces the ignition coil with individual coil packs at each cylinder, giving the engine computer better control of the ignition system.

Any improvement that will lead to more future sales is good. Maybe America's tax payers will get back some of that bail out money. For starters, GM can take a good look at reverse-engineering the Toyota all-aluminum DOHC 32-valve 5.7-liter V8 for their half-ton pickup trucks. For sedans GM should copy the Hyundai line of 4-cyl DI engines, with and without turbo. I cannot think of any way to improve on those two engines. For small diesels, Mercedes-Benz clearly leads the pack and GM would be wise to incorporate those engineering feats.

I think GM has the best in-house powertrain engineering, period. While the Ecoboost may be impressive, I have been told that the design actually came from Bosch engineers in India, as Ford has outsourced a lot of their engineering.

Mike L, you should include a ladder match or something, really make this thing a grudge match.

While I applaud all this reseach faculity etc!

Lets keep in mind this sounds a lot like what has gotten GM in trouble!

Just because it saves GM money, doesnt mean its good for GM!

Example =When you stated that GM divisons had different engineering teams and engines that were different across the brands of Chevy Ponitaic, Olds etc!
Its when GM started to combine and make look alike products, and remember all the conversy in the late 70s when GM started putting Chevy engines in Oldmoblile etc?

Its when GM started making generic products was the downfall of GM.When a Pontiac or Oldmobile was separate enity they did better, just look at how good Cadliliac is doing now, one thing its a totally different car than Chevy and Buick!

Hope GM has learned lessons on pass mistakes!

About the only earth shattering thing about the EB is the underwhleming fuel economy in spite of all the promise and hope of a 25+mpg v6 pickup. By the way, Ford didn't invent direct injection turbo engines. They've been around for well over 2 decades. Now back to the original topic.

You're talking about direct ignition system (coil on plug) whereas the article and everyone on here are talking about direct FUEL injection... Please do yourself a favor and stop talking because at first I thought well he means well now I see you're an idiot.


Who the heck do you think you are?

I have logged more miles and driven more Toyota's than ALL of you HATERS combined on this forum! In other words, unless you have owned one or currently drive one and think you know everything about them, do me a favor and go back into your cave.

Yes, I was talking about DIS direct ignition system that I had on my 1997 Tacoma 2wd and I was SPOT ON to what I was saying unlike you and others on here...

Oxi, please just stop, you respond to every comment that is critical of Toyota by shouting racist and resorting to typing in capital letters. It doesnt make your point any more valid, in fact you spend a lot of time appealing to emption and an illegitimate authority. Just because you have never had any problems with your toyota vehicles doesnt mean that there are none, you are not a good sample size when toyota sells millions of cars worldwide every year. Ive never had problems with my f150, but i accept that there are issues that may or may not show up in them, I know they are not perfect.

And to be fair, you said direct injection, not direct ignition, the two are far from the same and not interchangeable. Dont go back and change what you said to try and save face, for once admit your mistake and move on.

can we PLEASE stop with all this Toyota stuff i get it you guy like Toyota's give it a rest, can we have normal comments about what GMC is doing, (this is a story about GMC) how does this always turn into Toyota's comments

@ dan,

Usually Oxi brings it up and then it turns into a bashfest


Ford has had the Distributorless Ignition System (DIS) since 1990 in the 4.0L engine

I will gladly take the cast-iron block, pushrod V8 HEMI Magnum (or any other American V8) over an all-aluminum D.O.H.C. V8 any day. As a matter of fact I do have a HEMI Magnum great motor. A cast-iron motor is much stronger than an aluminum motor. Just like a 4X4 with a solid-front axle is more durable than a 4X4 with an independent-front suspension. Proven technologies!

Guys, thats just Oxi being obnOXIous, just don't give him the satisfaction of a bashfest. Oxi who in the h_ll do you think you are? glass houses and stones, rusty frams an bent tailgates, all have one thing in common, toyota.

@Noah- Toyota has versions of both the GR V6 and the UR V8 with direct injection. Those can easily go into the trucks, but they'll probably hold off until the refresh happens for each one (taco in the next 18mo). It's known that the Tacoma will get a new engine of some type. I'm hoping for a 4cyl turbo (with or without spark plugs), but it could be a direct injected GR.

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