458 Do you let off throttle when downshifting

I'm not sure why you would generally be on throttle downshifting?

If I'm downshifting it's typically because I'm braking in the lead up to a corner and need to get into the appropriate gear before the corner, to maximise speed at corner exit. I can't really think of any scenario where I would be on throttle and be thinking about downshifting - generally when you're on throttle your next gear change is going to be an upshift!

I can't necessarily answer your question about how the transmission behaves when downshifting while on throttle - however, I can say it behaves perfectly fine for me when downshifting off throttle.

 

On track I’d be braking when downshifting, but on the highway when you want to grab a gear to make a pass I can see being on throttle and downshifting. In that case I don’t usually let off the throttle, but I usually wouldn’t be full throttle either. Its always been smooth but I wouldn’t be in race or higher mode in that situation since I was just cruising around anyway.

 

Fair enough. If I've got an upcoming passing opportunity, personally I typically change down to the gear I'll want for the pass before I actually go to make the pass

 

I'm never on throttle when I downshift. What would be the purpose? If I want extra torque to pass and I need to shift to a lower gear, I still take my foot off the throttle when downshifting, its just intuitive.

 

This kind of driving behavior is trained by all these new cars with this auto downshift crap where you can throttle while downshifting and it'll put you in the lowest gear for max torque.

Being off throttle while downshifting is 101 level driving technique. You'd never do it in a manual transmission car, you'd definitely not do it in a single clutch and shouldn't do it in an old DCT. In an older DCT like in the 458. Its incredibly jerky if you downshift while on throttle, even moderate throttle, let alone medium+. I've had one person do this in my car and I yelled at them.

 

To get more attention on a drive-by at Cars and Coffee.

 

no

Yes

 

Fair point.

 

DCT can pull off pretty smooth shifts. Even on track sometimes you want to downshift at part throttle. Like when a long uphill turn leads into a straight. You’ve lost speed in the turn and want to power out. It’s not a big deal

 

From my longtime tech: It’s because that’s what it is programmed to do. Dual clutch transmission has 1-3-5-7 on one shaft and 2-4-6 on the other.

When you’re on throttle, it is pre-loading to switch to the next gear up, when you brake or coasting a while, it is preloading the next gear down. That’s how it gets these 80-100 millisecond shifts. If you throttle while in 2, it’s expecting 3. But if you psyche it out by braking and then upshifting, it will seemingly hesitate and sometimes buck a bit as it changes up and goes the opposite of what it anticipated.

 

on the brake when downshifting is even more desirable
Definite NOT on throttle as your posts states
The Ferrari DCT in the 458 is definitely NOT a Porsche PDK

 

To be fair it also takes into account which drive mode you’re in and what current roms are and whether you’re currently accelerating or decelerating

if you’re in race mode and at low rpm and have some pedal/throttle depressed I doubt the transmission is going to have the next higher gear pre selected