RudyP

Very cool! I remember seeing the video that Derek at Issimi made about it. Pretty wild!

VanMcQueen

Your 355 may not do it…yet.

Save the wear on your synchros and double clutch in older manual Fcars (and Pcars for that matter). Your mechanic (and wallet) will love you. First thing my mechanic showed me when I got my Fcar was to double clutch and shift from from first to third when cold. Had no problems with first to second shift ever, even when cold, but it makes sense to save that wear and tear on the gear box. Those cars are getting older and parts harder to find.

It’s interesting you can’t double clutch in modern Pcar.

GrantG

You can - it’s only occasionally that the throttle is not quite as responsive as desired when doing it.

AlexCeres

it’s pointless to double clutch a modern car with synchromesh

Maverick787

Looks like fun😳
https://m.youtube.com/watch?v=2SXPHwe3swI

GrantG

Sure goes into 1st gear much smoother from moderate speed when cold…

FourT6and2

I have quite literally never needed to downshift to first when moving. 1st is when you come to a stop or you're going soooooo slow that you'd stall in 2nd. Why would you need to shift to 1st "from a moderate speed"?

GrantG

In the mountains here, there are some very steep uphill switchbacks when you would be lugging the engine badly in 2nd…

FourT6and2

keep it in 2nd and just drift that sucker

348SStb

I am reviving an old thread to ask a few questions and also to make a few relevant comments. Too bad I missed this thread when it was active previously. I’ve also read the more recent 992 thread on this but decided to post here.

I may be shopping for a 991.2 Speedster soon, so this topic becomes relevant to me.

I did own a 2018 GT3 Touring May, 2019 — March, 2020. I honestly cannot remember this being an issue for me but I do not doubt it. I had the car a short time and anything before Covid seems a lifetime ago, doesn’t it?

=====

Questions

1) The first post on this thread and subsequent comments are slightly unclear because the “clutch out” step is not mentioned. “Heel and toe” downshifting is not specific enough because heel and toe can be performed with and without the double clutch technique.
That is to say — a proper double-clutch downshift proceeds as follows. While traveling along in 6th gear at 60mph, for example, and desire is to downshift directly to third gear, foot comes off accelerator pedal; clutch goes in; gear lever goes to neutral; **clutch goes out;** throttle blip to higher RPM with right foot; clutch goes in; gear lever moves to third gear; clutch goes out while throttle is applied for acceleration. This is double clutch downshifting — that’s what we’re talking about, right?

In the video above, Damien isn’t specific on this either.

Indeed, heel and toe can be done also with the synchromesh, which is off accelerator, clutch in, blip while changing the gears, clutch out, accelerate.

2) A software change was mentioned that would solve the problem. Did anyone ever succeed in this or does anyone know what the solution is?

3) Can anyone confirm if auto rev matching will do the blipping for him on a double clutch downshift? That is to say: after the shifter goes to neutral and clutch comes out, clutch goes back in, gear shifter goes to lower gear and the car blips the throttle on its own — driver refrains from applying throttle just before selecting lower gear; then throttle is reapplied for acceleration as clutch come out.

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I would like to make a few comments that would help both anyone reading this thread who is of a younger generation who doesn’t know what double-clutching is (and is open-minded to learn) and also anyone who thinks he knows what double clutching is but really doesn’t. I can’t help the haters, and there seem to be a few who commented on this thread. Alternatively, there’s Wikipedia and other literature that discuss the technique and its purpose.
<https//en.m.wikipedia.org/wiki/Double_clutching_(technique)>
<https://www.jdpower.com/cars/shopping-guides/what-is-double-clutching-and-how-does-it-work>

1) Anyone who says double clutching is “pointless” in general or “pointless if the car has a synchromesh” or “pointless if the car has auto blip” absolutely 100% does not understand (a) how a transmission works; (b) what the mechanical purpose of double clutch downshifting is. Period, end of story. I explain below.

Besides being fun, there is a mechanical purpose to double clutch downshifting. It’s not for bragging rights, fun, or for keeping things old school although those attributes may accompany.

On the contrary: it is almost a must in many cases and a must for those who don’t want to have a transmission swap and who prefer to blame themselves for their own mistakes instead of others (in this case, the manufacturer).
For example, if you’re cruising along at 85 mph in sixth gear and want maximum acceleration, you’ve got to go directly to third gear for acceleration. You don’t row down gear by gear. How do you go directly to third from sixth? Anyone who simply applies the clutch, shifts to third, and lets the clutch out is a complete amateur at manual transmission operation. In fact, such a shift is extremely stupid. It puts extreme stress on the synchromesh and is something that is 100% avoided by drivers with proper experience and training.

You double clutch downshift to go from a high gear to a lower gear during competitive conditions. You don’t ask the transmission to take it on the chin by forcing the synchromesh to do the work — enough repeats of that will often result in a blown transmission.

2) I was privileged to own four different Ferrari F355s. Two of them had the gated manual. The F355 had a mechanical actuated gearbox with direct transmission linkage. I also owned 360 and F430 gated manual vehicles — those were cable-actuated, as were my 348, Mondial t, and 456M with gated manual. My 512 TR was mechanical. There are advantages to the mechanical-actuated gearbox but the cable system was already perfected by the time Ferrari came with the 360 and Porsche has perfected it also. Not an issue.

3) Anyone who doesn’t know about double clutching is often someone of a younger generation, but not necessarily; we also cannot discount the worldwide problem of people doing something the wrong way for years and years and then thinking that just because they’ve been doing something a certain way for years and years that it must be the right way (we see this problem especially with construction guys who use bonehead techniques while they brag about how many decades experience they have); further, obviously such a person doesn’t know how to properly drive a Ferrari, didn’t own one, or didn’t care enough about the car to car to treat it nicely. No Ferrari owner who loves his car and who is educated EVER shifted into second gear without a double clutch upshift while cold; further still, second gear was skipped most if not all of the time while cold, whether by people who were educated or uneducated on the double clutch technique.
Yes this is a Porsche forum, but there is plenty of crossover.

4) I do not hate the auto-blip function. I think it’s great technology. I often do my own blipping (for both enjoyment and better results) but sometimes on double clutch downshifting, I will let the car do the blip. On my 2016 981 Spyder and my 2017 991.2 Carrera S, I always double clutch downshift when I want to accelerate via a lower gear. To those who might disagree — I’m sorry that I love my machines, understand how they work, and want them to last; and I’m sorry that I’m good at it, as are so many others are here as well.

**On my 2018 GT3 Touring which I owned only for a short while and drove quite sparingly, I imagine I used the double-clutch downshift technique via auto-blip instead of blipping myself which is why I do not remember this being an issue. I could be wrong — again, I’m not fully remembering.

====

Thanks for reading. The main purpose of my post here was to ask one of my questions above which I repeat below because (sorry to repeat) I may be shopping for a 991.2 Speedster soon.

2) A software change was mentioned that would solve the problem. Did anyone ever succeed in this or does anyone know what the software solution is?

VanMcQueen

348SStb:

Sorry, I don’t have answers to your specific questions (I ended up with a pdk). But I wanted to thank you for taking the time to write your post. Well thought out and written.

I let my wife drive my 308QV to a car show yesterday, while I followed in another car. I cringed because I forgot to tell her to shift from 1st to 3rd. No problems whatsoever, car shifted into 2nd fine, but it was difficult to watch. LOL.

markiegt3

Hi,

I have a 991.2gt3 and use the traditional heel & toe and never had a problem rev matching????

I thought the car sensed when it was moving so turned the soft limiter off, as I have done down shift well over 5k revs, I am sure, just being silly to put in 2nd for a 9k pull

markiegt3

Drove car for a service, heel & toe down change incl double declutch and revs went over 6K on the blip.

I do it in one fluid movement, so maybe the blip occurs while the clutch isn't fully released? Touch of overlap??

Dougr743

I just did, what i think he is says, went from 4th to 3rd rev match off, double clutches. So clutch to move into neutral, then clutch with revs to move into 3rd. It revved, pretty close to what was needed. I wonder if its a long delay that is occurring. like clutch to neutral, drift at idle, rev, while clutch is being pushing in? I am not sure how to get this to happen, 991.2 gt3 manual. Now if you have rev match on, it will cut the rev completely or act strange What i cant seem to understand, it while you are under braking, like the old days before rev match, you brake and gas, while engaging clutch at the same time, so it would have to be a brake while in neutral, while the car is at idle, due to not being in gear, then clutch and rev that is causing it?

alps

Regarding ECU intervention, I had a strange experience while tracking my 991.2 Touring recently. Sport mode on. Approached a corner in 3rd with around 6k rpm, applied the brakes hard intending to shift to 2nd, moved gear lever towards 2nd (not sure how far I got but I don't think I was fully into 2nd gear), changed my mind and decided to stay in 3rd (too much going on for the next corner), moved the gear lever back to 3rd, let the clutch out and car took off towards the corner pushing for the rev match required for 2nd gear which was maybe 7k+ rpm. My foot was off the gas. Pushed the clutch in and broke hard and the revs dropped and I continued through the next corner in 3rd but pretty upset at the computer intervention and lunge towards the edge of the track.

For the rest of the day, I was very careful and deliberate with the shifts (no reconsideration of gear selection midpoint) but was a bit freaked out by the unintended acceleration.

Sport mode is great but not foolproof and does seem to require you to commit to what it expects and don't change your mind. Another example of computers not being quite ready to replace humans yet.