Meh...10 speed DSG. Gimme 15 or 18 gears along with two sticks to shift them!
Twin Stick Pappy
Seriously, this whole "look how many gears we have" bullcrap is getting a little nuts. I realize a wider ratio spread and smaller steps are better, but at what point do you reach the law of diminishing returns? 10, 12, 20? Shoot, take a wide ratio CVT and stick the planetary gear set out of an old Powerglide behind it. Depending on what your needs are, you could rig it up for either super low range or super overdrive.
I'll just keep my 5 spd...thanks.
A 1L displacement TDI would not keep the 4-cylinders (thermal efficiency goes down as cylinder dimensions go much smaller) but rather go down to 2 or 3
So I just did some math and the surface area to volume ratio does worsen with more cylinders of smaller displacement. I just took a cylinder 8cm wide, 10 tall, for a displacement of 502.4cc. Dividing that volume into 4 smaller cylinders yields 125.6. Then, 2.5 pi r cubed was how I figured out the dimensions of the smaller cylinder. Radius 2.5198, height 6.2995, surface area 139.5596. So 4 of those little cylinders have 558.23 square centimeters, vs 351.68 for the big cylinder. 1.58 as much surface area for the same displacement? Wow. Hopefully I did the math correctly..No, the surface-to-volume ratio worsens (increases) with smaller bore-stroke dimensions.
Yes, that is true, say you have 1 shift from 5000 rpm to 4000, or 2 shifts, the first one drops to 4500, then the second to 4000, if you the same slip rate, you'll have the same shift time for the single shift as the 2.But the clutch slip is what makes a DSG shift time, and there's less clutch slip with closer ratios.
Yeah, my guess based on quick math and what I read is they probably limited the torque in the peak of the powerband, but carried that number up to 4000 rpm or so to get that nice 272 hp. And of course a turbo that makes power like that won't spool early enough, so they used the e-assist.with modern turbocharging and controls you can essentially tailor any shape of the torque curve you want.
Partly it's because they know people actually drive in the lower part of the RPM range.I do not understand why they undersize the turbos on the tdi so badly. They're going into cars, not pickup trucks.
Ah, wait until the gassers get hit with some of the same emissions requirements that diesels have now, in particular the DPF filter. That will hit their MPG the same as it did for us.If this is the same engine as in the new Passat we're getting here (240hp/500nm for us) it has a compression ratio of 15:1 or thereabouts.
With Mazda Skyactive gasser having 14:1 the engine types are getting closer and closer.
Who would have thought 10 years ago??
I don't know if I like this, the gassers are getting more fuel efficient and has good torque charasteristics, soon they'll be better than diesels
Do you need more than 370lbs of torque? my ALH vnt17 was around 375ft/lbs and it was plenty. All you need is a longer torque band not a short peak. With 10 (t e n) gears and a decent torque band the engine would be in peak power mode without the need for a crazy high torque peak surge.
My stage2 2013 was as fast as my more powerful ALH vnt17. Because it had better torque / power band and 6 gears. But the ALH was much more fun. Torque surge, smell, sound, smoke....