157dB

Thats the 1.6L non turbo engine in a cramped engine bay.
I would guess the even bigger 2.3L TWIN SCROLL TURBO
4 cyl for the 2015 stang will be swimming in the engine bay and
overheating will not be a problem.
But it is uncharted waters none the less...
But 300/300 ratings down low on the RPM scale?

http://motrolix.com/2013/12/2-3l-eco...rom-honeywell/

j-town_edge

EcoBoost is going to be an issue unless they change piston material. Just caught an article on Ward's Automotive today (had to for work) and a piston supplier brought up the point that turbocharged GDI engines run higher engine temps and they have seen dramatic increases of the piston head (aluminum) expanding, which causes a lot more friction in the cylinder. They suggested that for the first time they will be purchasing steel (in a 1 piece forging) for use as a piston head, as steel has a much higher resistance to thermal expansion. Wonder if Ford thought of that, because I'm pretty sure that most of Ford's passenger cars and even light trucks use aluminum piston heads.

Steve@Tasca

Ford has extensive experience with forced induction, I doubt we'll see any issues with pistons.


-steve

j-town_edge

I would agree, but we can't disprove the notion that steel has a much higher resistance to thermal expansion compared to aluminum. And I'm not just saying that because I work in the steel industry (SBQ).

Excerps-
Today, aluminum is facing a challenge as piston makers seriously consider steel as a core material because of its rigidity, resistance to thermal expansion and lower cost. Steel pistons have been common in medium- and heavy-duty trucks, but automakers now are highly interested in steel pistons as a way to reduce friction and fuel consumption while producing more power, says Horst Binnig, CEO of German piston supplier KSPG Automotive.

“Now we see steel going into mass-volume production for pistons,” Binnig tells WardsAuto during the recent North American International Auto Show here.

The move toward turbocharged gasoline direct-injection engines has raised operating temperatures to the point that aluminum pistons are under tremendous stress. They expand, causing excess friction within the combustion chamber.

Steel has different thermal properties and is able to resist expansion even as engine specific loads rise from about 50 kW to as high as 80 kW today, says Alexander Sagel, president of KSPG’s Kolbenschmidt piston unit, currently the world’s No.2 piston maker.

“With steel, you have much better control over friction, and you can significantly reduce friction between the skirt and the liner,” Sagel says, adding the thermal expansion coefficient of aluminum is 26; for steel, it’s seven. “That means aluminum is three times more likely to expand.” Steel is heavier than aluminum. But, when combined as a system with optimized hardware such as rings, liners and pins, steel pistons actually can result in an overall weight savings, Sagel says.

There are packaging considerations as well. A steel piston is more rigid than one made of aluminum, so it can be smaller. The piston crown can sit 30% lower than with an aluminum piston, allowing an automaker to reduce an engine’s deck height during the design phase, Binnig says. KSPG can manufacture a steel piston as a 1-piece forging, and the supplier has patents for both the design and process, which Sagel describes as “a kind of warm bending process."

If this is starting to take place in Europe, and Ford Europe gets involved, it'll make it's way here eventually.

Steve@Tasca

I asked a friend/customer of mine that's a high end racing engine builder about this. He builds engines for some of the countries quickest and fastest Mustangs including 1/4 mile record holders and top speed record holders.

Here's his response.

"I have not read about steel pistons coming into favor either in SAE or Engineering news.
Diesels use a fair amount of steel top ring insert cast into the piston to help support the top ring, but the only thing I have seen is hard anodize in the top ring area like in the 5.0 piston.
Recip weight would be against OE consideration of mass and throttle response. The other negative is steel does not convect the combustion heat as well as aluminum.
I would be very surprised if any OE would go that route."

-Steve

5.0GTCS

Yep, good point there, I had a 2004 SRT4 putting out 400hp/400tq with zero issues... and that was a pretty quick machine, tracked and it here and there and had a ton of fun with it, then sold it and bought current 2011 GTCS... funny how many drivers underestimated that ride tho, till they realised what they were dealing with, it's gobs of HP/TQ and lightness was equivalent to a 500 Hp ride.