V-6 Ecoboost: 350 or 420 Torque?: Grassroots Motorsports forum: Grassroots Motorsports Magazine

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June 17, 2011 4:08 p.m. DWNSHFT Reader

I searched and I don't think we've discussed this. When Ford's Ecoboost V6 came out in the Taurus SHO it made 350 torque at 5000 RPM. A year later it was introduced in the F-150 and made 420 torque at 2500 RPM. [In both applications it makes the same 365 HP at the same 5500 RPM.]

Does anyone know what is different in the truck motor? More boost is the obvious possibility, but why doesn't the Taurus get the benefit?

One possibility is that the Taurus transmission couldn't handle the extra torque. Or maybe the truck could fit a larger intercooler, allowing more boost.

It's also unusual that the truck motor makes more torque at a LOWER RPM. Any possible reasons?

Thanks for your thoughts!

David
June 17, 2011 4:13 p.m. mndsm SuperDork

I'm thinking it's all retuning. I'd be willing to bet that the transfer case in the SHO couldn't handle the kinda power that a full boat Ecoboost would throw at it. So you turn down the torques, remap it so that the drivetrain isn't getting slapped as hard at the line, and there ya go. I'd be willing to bet that the Ecoboost in the truck and the Taurus are a tune away from being identical. And I bet the first Taurus guy to figure that out snaps halfshafts or grenades a diff in short order.

Gotta remember, Ford's been putting a lot of torque in trucks for a lot of years.... not so much with AWD cars.
June 17, 2011 4:26 p.m. DaveEstey HalfDork

Because they didn't want the SHO Taurus to be faster than a Mustang GT haha
June 17, 2011 4:38 p.m. alfadriver SuperDork

I happen to know....

The big difference in the engines is the SHO/MTS/Flex/MKT powertrain is intake variable cam timing, whereas the truck engine is twin independant variable cam timing.

Exhaust, turbos, intake, intercooler- all different.

There are a bunch of detail changes inside the engine, which does change how it's tuned....

And the trans is more capable, too.

But the engines are not really the same.
June 18, 2011 1:50 a.m. Vigo Dork

The only reason the difference was created was for the non-truck transaxle and driveline. I think this was stated in the newest issue of motor trend.

Regardless of whatever changes they made to limit torque, the issue is not what the motor can take but what the transmission can take and still be able to be warrantied for years and years without costing a mint.
June 18, 2011 12:04 p.m. alfadriver SuperDork

Vigo wrote:

The only reason the difference was created was for the non-truck transaxle and driveline. I think this was stated in the newest issue of motor trend.

Regardless of whatever changes they made to limit torque, the issue is not what the motor can take but what the transmission can take and still be able to be warrantied for years and years without costing a mint.

Motor Trend takes the rather simplistic reason and runs with it. There are other issues, too, but the trans is one of the bigger ones. Not only, though.

As for the limits- there are some other natural limits that cuase torque to be limited as well- turbo speeds, temps, part capabilty, etc.

Just like the trans- everything can take the increased torque- the question becomes how long- what will fail first? The 6F trans is pretty stout, but the 6R is designed for the truck.