Specifying Performance for the Cadillac CTS

I have written about my recommended engines for the Cadillac CTS — I would like to see the LLT DI 3.6L 304hp V6 as the Standard Engine, and the L94 or LS3 403 or 426 hp V8s as the Performance/Premium powerplant.

Let’s put these more in performance specification form.

2010 Cadillac CTS

The Current top non-V CTS Performance Sedan will go 0-60 mph in 6.3-6.5 sec, and corner at 0.87-0.9 g on a 200 ft skidpad.   The base CTS sedan with 270 hp V6 is a bit slower and does not corner quite as well; so say 0-60 mph in 7 sec and 0.83-0.85 on a 200 ft skidpad.

I would like to see the current Performance Sedan as the ‘base’ model.  The counter-argument is that some people want the fuel economy of the 3L and are not that focused on Performance, so I am willing to compromise on this point.

For a CTS Performance Sedan with sizzling performance in today’s market Cadillac needs to attain 0-60 in under 5.5 sec, and a consistent skidpad result above 0.9g.  I believe that the easiest way to get there is to put in one of their current excellent off the shelf V8s, but I would be equally happy with a forced induction V6 that brings the power.

The skidpad / cornering issue is weight.  Until the next CTS refresh that seems fixed.  What can be altered is adding more rubber.

With the retirement of the STS this year, now would be a good time to bring the MR suspension to the CTS Performance sedan.  With the right tires and the right tuning that should keep it over 0.9g on the skidpad.

A true CTS Performance Sedan with 0-60 in under 5.5 sec and that corners at 0.9g would still not match the super car CTS-V performance, but it would be a terrific value and aspirational model at its current price point.

In Pursuit of a Lighter Cadillac CTS

One of Cadillac’s plans for the next Cadillac CTS refresh is to make the CTS one of the lightest cars in its class.  One assumes they will do this through additional use of Aluminum, and high strength steel.  The advantage of high strength steel is that for the same properties a thinner, lighter piece can be used that has the same or better strength and durability.

There is a 2-3% improvement in fuel economy for every 100 kg (220 lbs).  So although the EPA cycle is complex, in general a 28 mpg CTS might break 30 mpg with the loss of around 500 lbs of weight from its 3,681 lb curb weight.  Obviously there is a limit to the fuel economy that can be gained in this manner, since Cadillacs one can safely say will always have some weight.  Cadillac’s goal of being the lightest in their vehicle class seems ideal.  This goal is one that will have to be revisited in the crowded markets Cadillac competes in.

Cadillac CTS Safety Cage

The Cadillac CTS currently uses Advanced High Strength Steels in strategic structural locations.  Advanced High Strength Steels (AHSS’s) are multiphase steels which contain martensite, bainite, and/or retained austenite in quantities sufficient to produce unique mechanical properties (transformation hardening).  AHSS’s exhibit an excellent combination of high strength and high formability resulting primarily from their high strain hardening capabilities. AHSS’s can be further classified by tensile strength; the ideal application for different tensile strength AHSS’s varies.

A recent study by Lotus Engineering confirms that a total vehicle, synergistic approach to mass reduction is feasible and could result in substantial mass savings with minimal piece cost impact.

I am very excited about the emphasis at Cadillac on weight management, as it will also make my favorite Cadillacs more nimble and athletic — when you lose weight you just FEEL better!

Competition improves the breed Send more LLT V6 HP

Motor Trend did an early test drive and acceleration test on the 2011 Mustang with 3.7L V6 engine, managing a surprising 0-60 time of 5.1 seconds from the base Mustang.  Why does this matter on a Cadillac blog?

The base Mustang competes directly and aggressively with the V6 Chevrolet Camaro.  The current 304 hp V6 Camaro outsells the current Mustang, partially because it out-accelerates the 2010 Mustang V6, which got the old 210 hp 4L engine.  The new hotter base Mustang with the new 3.7L DOHC V6 makes 305 hp, and will ‘put the hurt’ on the current V6 Camaro, if the Mustang consistently manages 0-60 times of around 5.1 sec and the Camaro does the deed in around 6 sec.  Similar hp, but the Camaro is heavier.

To respond, Chevrolet will need to pump up the volume on the LLT DOHC DI V6, perhaps by 40-50 hp to overcome the Camaro’s weight disadvantage.  Generally in this weight class, 10 hp = 0.2 sec difference in 0-60 time.  BTW, another thumb rule in this class is that 100 lbs = 0.1 sec difference.  So the Camaro needs a minimum of another 30 hp, but another 50 hp would be safer.  So that means getting the LLT V6 up to 350 hp.

This is an exciting development for Cadillac because the CTS family shares the LLT V6 with the Chevrolet Camaro.  So hopefully any ponies that GM Powertrain prepares for the Camaro will go right in to the CTS as well.  Doesn’t always work that way, but the current CTS is also coming in high in its class for the acceleration tests, so that makes a good case for sharing.

What can GM do to increase the V6 output?  Tuning the LLT to run up to 7,000 rpm should get it to 325 hp.  Since it is a variable valve timing engine, there is no disadvantage to tuning at the top end.  Work on a more header-like exhaust manifold, and improve the exhaust port flow on the LLT should yield 20-30 hp, which would put the engine at 345-355 hp, with almost no recurring increase in cost for the power train.

Oh sure Bruce — if it is that simple why doesn’t GM do that already?  Because the LLT was meeting the design spec already — a great high value V6 that puts out more than 300 hp smoothly and with great MPG.  But now we need the more, and GM Powertrain needs to turn up the wick and send us a 350 hp LLT.