Speciale on the track + question about DCT

Watched the video.

We've tracked our Speciale quite a bit, and I have another day's worth in 2 other Speciales.

FWIW, I'll turn TC off but leave ESC on; generally speaking, if you're driving well, ESC is really just a safety net and should not have any compromise on the car at a DE event.

As for the downshifts, generally speaking no you should not be getting any rear wheel lockup or tires chirping, if anything the DCT and software do a great job of managing the shift, blips and chassis (eDiff).

At around 3:39 in your video, I hear some tire and see the rear end step out a touch, but that sounds like ABS induced with the weight forward and you turning in. However, hard to tell from just this view. Remember in ESC Off the ABS mapping changes as well and gets a bit more aggressive. Engine blips sound fine on downshifts.

To the best of my knowledge, there have been no software upgrades to the gearbox, so we are all running the same maps, unless I missed something.

 

Looks like fun! The only chirping I hear sounds like normal ABS and didn't seem to be related to the downshift, but perhaps I'm missing it.

 

another thought - all Speciales in NA came with the Ferrari Telemetry as standard (it's a data logger, not telemetry, but I guess telemetry sounds better in the marketing dept)

I've only played around with it a bit, but you should be able to get brake pedal pressure information off and have it overlaid on speed. Impossible to tell from the video when you're on the brake and how hard, relative to the speed, and when you are timing your downshifts.

Regardless, you should not get, and probably are not getting, rear lockup from the downshifts unless something is severely wrong with the car (which would have alarms flashing).

However, heavy ABS braking creates a lot of chirp and depending on how you are loading/unloading the chassis, it can sound and feel more pronounced (eg. turning the car in while it's on its nose with a lot of brake, the rear will rotate and you'll hear the tire).

BTW what track is that? The Farm (?).

 

You could tell what is going on with a simple AiM Solo DL...

 

That can't be right; I would have it looked at personally. Maybe it is just a clutch adjustment which is needed.

 

I actually set it up and it worked pretty well on the iPad app (for what it is). Quite candidly, it's probably the best "onboard, as delivered" data logging and analysis product I've seen on a car. Having said that, it does help to know how these systems work to get it set up and working. Apologies for the obvious, but getting it to work required me to actually follow the manual. If you can pull raw data, might be worth a phone consultation with Peter Krause. (it's Marelli based and behind the interface seems to act like Wintax). OR, if are in Tampa, go by the dealer and have Onofrio Jr. show you.

this is definitely not right. the gearbox will not accept a downshift IF the revs will exceed the limiter. it will also blip the appropriate revs with the appropriate intensity to match the engine revs/gear/rolling speed. you may notice the different maps (Sport, Race, et al) have different triggers. the car also adjusts itself (eg. will react differently if you go from full throttle to full brake, vs. partial throttle to soft brake).

Only thing I can think of is 1) there is a problem somewhere, which I've never seen/heard of 2) you are downshifting at the very top limit of revs, and the engine braking is overwhelming, which it should not be, but somehow is...

To Peter's earlier post, would be interesting to see the wheel speed sensor readings. A DEIS I believe can be used in real-time to monitor this (DEIS for road cars). If your tires are chirping, it means the wheel speeds are at/near zero during the downshift, or they are being dragged for some reason.

 

Hmm. I did this over a year ago, so I'll have to get my iPad down to the car and refresh my memory! I do recall it took me a couple attempts (user error) and remember you need to have the USB key inserted into the right receptacle (but sounds like you do that if you're pulling video).

IIRC I had the issue we all seem to have when pairing devices on bluetooth - i.e. I was jumping ahead too quickly and the device was not captured. But let me try again. I also think at one pointed I deleted the app and reinstalled it.

 

I'm sorry I hadn't seen this thread sooner. Last summer I was running a friends speciale and sure enough on downshift it chirps the rear tires. It has nothing to do with abs or esc. To me it seemed like an issue with rev matching on the transmission programming.

Imagine a downshift in a manual car without a rev match.

I have watched many cars on video as well and have not seen it in other cars. Your report is the first other than the one I was driving.

 

Why on earth should I do downshifts without braking in a rev-range where the rear wheels might lock up ? I would never rely on electronic assistants...

 

I didn't notice any chirping in the videos other than occassionally of hard braking. This is just a thought, what if it is the drive belt and not the tires? The belts will chirp on hard upshifts, I could see them chirping on a hard down shift as well.

 

Drive belts chirping? Really? How?

Also, 458's have chains.

No, I think we're talking tires.

 

I think it really is an issue with the DCT program and traction. Becareful as a poorly executed downshift in a stick car can cause a spin and the fact your tires are chirping on downshifts says you are breaking traction and that upsets the car's balance. Not something you want...

 

the 458 engine's valve train is absolutely chains.

However, the alternator, A/C compressor, et al are all spun by a (more traditional) belt. About $70....

These belts can slip slightly and "chirp", particularly when engine rev changes are abrupt (eg. a high rpm, aggressive downshift throttle blip). Across our cars, I never heard it, but I HAVE heard it on other cars.

I am unsure if it is an adjustment, material or contamination (i.e. did someone spray stuff they should not have on there) issue.

As for downshifting, unless your DCT has an issue OR the programming is off, OR you happen to be timing your downshifts such that the tires are exactly on a surface with different friction levels, the chances that the tires are instantaneously locking (chirping) is very slight. I'm sure you can make it happen (i.e. downshift in a puddle then continue onto dry pavement).

 

Since you have a datalogger just post screenshots of the trace overlays. Should be pretty obvious if the rear is locking.

 

The belt squeak is a normal and known issue on all 458's and more pronounced on the Speciale, just about every one will do it if driven hard.