2016 Cadillac CTS-V Prototype Steps Out

[Bruce Nunnally]

The 2016 Cadillac CTS-V is coming. A 2016 CTS-V prototype recently dazzled spy photographers by stepping out for some testing in little more than swirl camouflage, giving us a sneak peek at the next CTS-V's aggressive new sheetmetal, grille, and bazooka-sized exhaust pipes. This particular Cadillac CTS-V prototype gives us our best look at yet at what the next CTS-V will look like. Up front, the CTS-V gets a new grille dominated by vertical lines, rather than the mesh design that we've seen on the past two generations of CTS-Vs. The new grille mimics the ones we've seen on ATS-V prototypes, leading us to believe that this is the new face of Cadillac's V performance brand.

Read more: http://wot.motortrend.com/1402_2016_cadillac_cts_v_prototype_steps_out.html#ixzz2tuvLNyNp

[Texas Jim]

[Cadillac Jim]

Nice look, no technical data - bit it IS coming!

[cdgrinci]

As with most spy-shots, can't glean much from the photo, but good to know the actual vehicle (in this case the "V") is coming.

[Cadillac Jim]

The big cosmetic changes are the four tailpipes instead of two huge ones, and the vertical-bar grille replacing the cross-hatch grille.

The platform is updated, and lighter. Everyone is assuming that the powerplant is updated too.

The Nuremburg time is 7:28, I believe, so there is a lot of room for improvement there. I heard that they are within three seconds of that with the CTS V-Sport. I expect that they would get ten seconds or more with the existing engine and transmission. If they go to a seven or eight speed with 50 hp or 100 hp more, they should be able to get in the 7:10 area. But probably not with street tires.

[Bruce Nunnally]

TOTD: What Does the 2016 Cadillac CTS-V Need to Be the Best?

Read more: http://wot.motortrend.com/1402_totd_what_does_the_2016_cadillac_cts_v_need_to_be_best.html#ixzz2uHxKKLGK

[Cadillac Jim]

Lighter weight and lower CG are key, of course. The suspension design point parameters - pitch and roll axes, anti-dive and anti-squat, suspension compliance and damping - must be built in, except damping, which is switched. Unsprung weight affects stickiness, all other things equal. Brakes are OK now. Then, it's tires, tires, and tires.

A little thing that can affect lap times is steering feel. I think more feel in the steering in the sport mode would improve driver input in the turns.

For better times, they might want to look at improving the intercooler. The one they use now is a bit of a mystery to me, since I have never seen a comprehensible cutaway diagram or description, but it seems to be a reverse-flow heat exchanger, with the hot air coming from the rear of the engine through two long tubes to the front of the engine, with the water going the other way. That's a good concept. Perhaps going to plated copper in the innards would improve efficiency.

A world beater would be an extra Freon compressor with the evaporator as part of the water flow for the heat exchanger, providing cooled water for the heat exchanger. This would be independent of the A/C used for the cabin.

I understand that they are going to a seven-speed or eight-speed transmission. It seems to me that if they are going to have four planetaries, they can have 15 speeds and reverse. A simpler design using five planetaries provides sixteen speeds with reverse. That's as good as a CVT as far as PCM control is concerned but handles the power and torque necessary for the CTS-V. You know that this is coming, and it's not too far away. Why not be the leader here?

Better fuel economy would be a plus, but not important in the practical sense; running the numbers shows that the difference between 15 mpg, 20 mpg, and 25 mpg for 12,000 miles a year at $3.00 per gallon is an extra $600 for 15 mpg over 20 mpg, and a savings of $360 over 20 mpg if you get 25 mpg. This is all down in the noise for a luxury car but it is a big deal in product image. So, variable displacement, low RPM cruising at any speed using the new transmissions, and economy algorithms in the PCM except in sport modes are important for product acceptance.

With an automatic transmission and a really good TCS/ESC you don't need a launch button, as I have found with my CTS-V. As long as the steering wheel is perfectly straight, the PCM will deal well with whatever you give it and whatever surface it finds. With a standard shift, you probably will need a launch button because the PCM has less control.

There is a lot of talk about dual-clutch transmissions in recent years but they are basically two transmissions and you switch back and forth between them as you go through the gears. This does not strike me as an elegant solution, except possibly for large trucks or large racing cars or some such because it achieves little more than a good electrically controlled set of clutches/bands on a planetary, but can double the size and weight of a transmission. And, skipping one gear is a bit awkward; one must shift from even-numbered gears to odd-numbered gears and vice versa.

[airmike]

Personally I think more gears is not a good thing. As it is with the 6sp auto, the dang thing has a long way to go to get to the appropriate gear at times. Adding more, means more time getting to the correct gear for the change that has occurred. I would think just getting the higher overdrive would be enough, if its gas mileage they are after. Can you imagine the car has shifted to 7th gear in town and you press the gas for an aggressive acceleration around 45, its a long way to 2nd. I don't think they completely skip to 2nd like you can a manual. I have not driven an 8 sp so maybe its not like that, but both my 6sp auto's are.

[Cadillac Jim]

With an PCM controlling the transmission, you don't have to use all the gears. With the hypothetical 16-speed, one concept is that the spacing between the gear ratios would be very close to 1:1.13 apart and provide the same RPM drop for ratios over a total range of 7:1 from a loafing high-speed cruise overdrive to a 4:1 parking-lot navigation low gear and stuck-in-snow-rocking gear. In a low throttle normal start to 40 mph from a standing start, you would use 1st, 3rd, and 6th, for example. But whatever gear ratio you want for whatever circumstance that arises, the transmission will offer it and the PCM can be programmed that way.

No one wants to go through 16 gears, one at a time, in most driving. But you want to hold the engine right at redline to get the best possible acceleration.

The challenge is to meet dual-clutch shift performance in a single transmission.

There is a lot of talk in the thread at Bruce's link about AWD. I'm ambivalent about this myself, mostly because I've never experienced it as a driver in a CTS-V or other high-performance car. I have no problem with my CTS-V in snow with the Goodyear F1 Asymmetric All Season tires so I don't see the need for AWD in snow. As far as grip is concerned, it has plenty of that too. If power was to the front wheels too, perhaps it would not be as sensitive to the wheel being straight on launch but I suspect that you would just get different behavior on full-power launch with AWD, not a loss of grip. Lesser cars just smoke the tires or turn sideways or worse, and some of this may be a problem with a manual transmission, even with TCS and PCM-modulated throttle-by-wire.

I see some mention of a launch mode in the thread at Bruce's link too, but not as often. I think that the present CTS-V solution of making the PCM deal with launch using the TPS and VSS and wheel speed inputs and such is better than requiring the driver to punch a button.

[jaxeagle]

Personally I think more gears is not a good thing. As it is with the 6sp auto, the dang thing has a long way to go to get to the appropriate gear at times. Adding more, means more time getting to the correct gear for the change that has occurred. I would think just getting the higher overdrive would be enough, if its gas mileage they are after. Can you imagine the car has shifted to 7th gear in town and you press the gas for an aggressive acceleration around 45, its a long way to 2nd. I don't think they completely skip to 2nd like you can a manual. I have not driven an 8 sp so maybe its not like that, but both my 6sp auto's are.

Totally agree. I drive an 8sp shiftable auto now and it is totally that way. darn the fuel economy crap.

[Cadillac Jim]

If the PCM controls the transmission, the time to shift from any gear to any other gear is the same. Engine RPM can be pulled down or blipped up using the throttle-by-wire control of the gas, timing, and even cutting the fuel injectors if it pulls RPM down quicker and humors the cat.

In other words, there really isn't any such thing as too many gears. What you are complaining about is that the PCM programming doesn't suit your driving style.

[Texas Jim]

If the PCM controls the transmission, the time to shift from any gear to any other gear is the same. Engine RPM can be pulled down or blipped up using the throttle-by-wire control of the gas, timing, and even cutting the fuel injectors if it pulls RPM down quicker and humors the cat.

In other words, there really isn't any such thing as too many gears.

What you are complaining about is that the PCM programming doesn't suit your driving style.

That's why I fixed mine so I could change when and how it shifts so that it WOULD better fit my driving style...

[Cadillac Jim]

This is also why the existing six-speed has an auto sport mode, so it can skip gears in sport mode. Manual shifting goes one gear at a time, which can be very quick but not as quick as skipping gears. For example, coming out of a sweeper into a sharp hook the other way, you would want to downshift two or three gears while working the steering wheel, which the sport auto can do nicely. You aren't using one hand to work the ratchet shifter or trying to keep track of where the paddles are on the steering wheel.

[airmike]

I am gonna have to put it in sport mode and just drive around and see what the result is. Having said that, Cadillac Jim, If the car has 8 gears forward, are you saying it is going to be just as irritating when in D and goes from gear 5-2 or more irritating?

I am not really trying to be humorous here either. Do you think I need to get the trans reprogrammed to suit my style or is this just something I get to live with. Assuming sport mode is more to my liking, it really doesn't seem right to have to put in sport mode just to drive around. Honestly it's not a deal breaker either way, I love driving the car, but I could love it more!

[Cadillac Jim]

The problem with the four-speed, as with four-speed transmissions since 1949, is that a downshift to 2nd or 1st is a pause while the engine revs up to synch with the required RPM followed by a roar and a lunge forward. With the six-speed, that can happen if you suddenly nail it, but with the delay shortened by the faster-revving Northstars and LS V8's and the DI V6 and any of the turbo/supercharged engines. But I find that with the six-speed, the transmission keeps the RPM between 1200 and 1500 at light throttle, and at progressively higher RPMs as the throttle angle increases. In the sport mode, shifts are firmer and quicker, and lateral acceleration will drive a higher RPM - i.e. a downshift, and there is a second or two of grace before an upshift if you come off the throttle. Not having taken the car to the track, I'm relying on posts here and elsewhere about the auto sport mode on the track, but my feeling is that I would rather have both hands on the wheel to keep a tight line in the hairpins than deal with a manual shifter, if the RPMs are kept up where they need to be for optimum and predictable throttle response, because these are maneuvers at the limits of your tire's ability to hold if you are trying to manage to get your best time through the maneuver.

As for the street, driving alone in light or zero traffic I often put the suspension in the sport mode and the transmission in the auto sport mode for normal driving. That gives the best overall steering responsiveness and feel and the car is always in the right gear for best throttle response. But I never drive like I'm on the track on the street. Nevertheless, 0.8 g turns are effortless and the downshift happens during braking or turning, not when you tap the throttle coming out of the turn.

As for "irritating," well, the eye is in the beholder. I will say that in my 1997 ETC the PCM tunes the transmission shift points and shift firmness for the driving history of the driver, as determined by number on the fob that last unlocked the car. I would assume that this is true of your 2006 XLR. So, if you putter along in traffic all week and then complain about a lazy transmission when you nail it, well, perhaps your experience might be a little different if you engaged in a few minutes of spirited driving and saw the difference in the transmission. But the sport auto mode is there anytime, just shove the shifter to the right. If you do use a manual shift, you put it back in the auto mode by holding the stick or paddle in upshift for about two seconds. The continued display of the transmission gear in use indicates that the transmission remains in sport mode.

Be sure and use your fob every time you get in the car to be sure that it remembers you properly. For best results and variable driving habits, use two fobs, one for puttering along and another when you want to switch to the other PCM program. I don't know whether or not you would have to stop the car and shut it off or not, but I suspect not.

[airmike]

I will give you an example of my complaint? I have a 40 mph street that I will drive 45 with cruise on (saves on tickets), then turn onto another 40 mph street. What I like to do is accelerate (briskly would be my description) not floored, maybe 3/4 pedal. I do not try to go around the corner very fast, but just before getting straight I like to feel the push. That is when it seems to occur on either my xlr or my wifes mustang (both 6sp auto). The reason I blame the 6 sp is because I don't notice that big pause in the sts, driving the same style.

I have gone off topic (maybe) long enough for something that isn't going to change anyway. Jim I would ask you to try the scenario I explained and tell me if you feel similar in your car. Bruce Nunnally, your drive train should be just like mine, what say you?

[Bruce Nunnally]

If I want ready-now acceleration I use sport mode and manual shifting and downshift ahead of needed acceleration event.

I am not certain I understand the scenario - you go 45/40, turn onto another 40 mph zone, accelerating thru turn to engage stability control?

[airmike]

The scenario was driving at 45mph cruise on, and slow to turn at a very reasonable pace, then accelerate rapidly (not floored, maybe 3/4 pedal). Nothing excessive ever. No tire slip, no stabilitrac..If I only use slow grandma pace acceleration it doesn't shift to 2nd gear and the pause is not noticeable. If I push the pedal enough to shift to 2nd it has a long pause. I am not sure pause is the correct description though. This is what started me on the thought that if I were to be driving with cruise on, in an 8sp tranny the pause/hunt/?? for second would be even more exaggerated. Although an 8sp would likely not be in any higher gear at 45mph with cruise on than a 6 sp.

[airmike]

p.s. my car shifts into 5th at 44-45 mph under no acceleration.

[Cadillac Jim]

The pause is to gently engage the transmission before applying power, and is not something you will see in the sport mode.

My transmission upshifts at very light throttle whenever doing so will put the engine RPM at its minimum for good driveability, which is 1200 RPM for my 6.2 liter LSA in normal mode, higher in sport mode. I suspect yours does the same, but the final drive ratio and engine RPM settings will differ.

[Bruce Nunnally]

The aisin 8 speed in the CTS is likely pretty different from the GM 6speed in my STS-V or the coming GM 8speed

That said, the scenario presented may be confusing for transmission -- you are not in a hurry (not max throttle) but need to downshift, so softest imperceptable downshift preferred (?), even if not snappiest shift