Petevb

Again, it is not. Please research on Ferrari's home page or eslewhere. If you do all will become clear, for example:
"The engine's full 561 lb-ft of torque being available only in seventh gear. As on the California T, Ferrari has tailored boost curves for each gear. So in seventh, you get a torque curve as tall and wide as possible for freeway passing. In the lower ratios, boost is artificially restricted at low revs"

See "response time to throttle input", previous post. Read it through a few times, I'm sure you can get there.

Yep, I've tuned on a mustang actually. Mind explaining why the stock car's making boost 1500 rpm late?

sticky

What becomes clear? So Ferrari has boost per gear? And? What does this have to do with increased boost pressure not resulting in increased lag on the 991.2? The entire point you are incorrect about?

Regarding tuning on the Mustang, sure, I can explain it for you. Load on a dyno is not often the same as load on the street. Inertia dynos in particular will show slower spool for this reason.

Do you expect a car to spool on the dyno the same as it will in the real world? Didn't you notice different torque peaks/curves in different gears in the graph you posted?

Porsche's spool claim is from their own testing. My own testing shows the 9A2 spools incredibly quickly and 1000 rpm sooner than a BMW S55 motor on the same dyno. BMW claims it starts to spool at 1800 rpm.

I'd be happy to refer you to my testing if you like.

How does any of this change the fact you are incorrect about tuning the 9A2 engine and your claims that less boost results in quicker spool when it's the turbo hardware and engine that determines this?

Petevb

Again not answering the question, but bringing up a good example that I mentioned before. Porsche found 10% torque at 3.5k by increasing displacement 5% above. Nice showing.

The aftermarket finds over 30% torque at the same point while increasing displacement 8%. The aftermarket (and Porsche themselves, in house) also take the engine out to 4.2 liters and beyond safely and reliably. Porsche never chose to sell that.

I suppose you think Porsche is simply technically unable to keep up with other manufactures in the HP race? They are falling behind because their engineers simply can keep up with the Italians and Americans. Or maybe they are intentionally choosing to limit their offerings for other reasons? I wonder...

Petevb

Ferrari uses lower boost in the lower gears to improve response. It's that simple. They spell it out. Reducing boost reduces the time it takes to reach that boost. Reduces the response time- the time from asking for 100% power to getting it.

Not hard, or at least I would not have thought so.

It's the same or higher on a brake dyno like the mustang. That's the entire point.

sticky

I don't know what you're going on about. You claimed Porsche intentionally limits torque in NA motors. I'm saying that is a load of BS. Now you're deflecting to who knows what.

In the turbo engines, sure, Porsche isn't giving the 991.2 more torque to maintain an artificial hierarchy. A tuned 991.2 Carrera will stomp a 991.2 Carrera S. Just like a tuned 991.1 Turbo will stomp a 991.1 Turbo S. Didn't Porsche only change software on those btw? I wonder why.

Porsche obviously is offering incremental increases with the GT3. 3.8 to 4.0. 8700 rpm to 9000 rpm. Now we'll see 4.0 to 4.2. Then we'll see the end of the road. They aren't picking up torque with boost but displacement.

I think Porsche is offering tremendous power and performance today. It's why I bought one. So what are you talking about?

What does people in the aftermarket increasing displacement have to do with anything? Haven't people always done this? I can increase bore on my motor and take it to 3.8 liters. And? Do you like seeing yourself type or what?

sticky

How is lower boost improving response? Are you sure it isn't more of a traction issue? Boost by gear is implemented for those reasons. You're literally ignoring a 488 GTB graph with more boost that refutes you.

Lowering boost is not going to improve response. You're telling me I can just dial out some boost pressure and my turbos will spool more quickly? LMAO. Wow, I wonder what they feel like at 1 psi! You can't shift the torque curve to the left by dropping boost you can only reduce torque.

It's the turbo hardware that will determine the spool NOT THE BOOST PRESSURE. More boost, less boost, it's still going to start to spool the same based on the wheels/compressor map every time.

Petevb

I don't know, go ask Ferrari. Maybe they can explain it to you, I clearly can't.

Petevb

Done. Good luck sir.

Maybe someone got something out of it, sorry for taking the thread off track OP.

sticky

So I googled that article you quoted and are taking liberty with. Um, they don't limit boost to improve response. They artificially limit it to produce a more linear curve. Porsche tunes the 9A2 to offer a very flat curve as well but this is done to mimic an NA motor not to improve response. You literally are just making up your own narrative:

Not a single word about lower boost improving turbo response. You know why? Because it doesn't.

sticky

Go ask Ferrari why the laws of physics don't apply? Ok, cool.

Now with that nonsense out of the way back to the 9A2.

randr

Figures as measured 991.2 S from fully closed throttle:

1800RPM ~ 3s
2000RPM ~ 2s
2300RPM ~ 1s
2600RPM ~ 0.5s
2900RPM ~ 0.3s

NA 0.3s to 0.2s - I'm not sure why people believe NA cars throttle response is instantaneous? it never has been.

The numbers above are from fully closed - this is not the real world, it is technical lag.

In the real world the .2 series hold boost for up to three seconds........so if you have been over 3000RPM........

Moreover if you have Sport Chrono you can hit the magic button which both optimises boost, response and gear.

As I have said previously, on track, lag is a complete non-issue as you're always over 3500RPM and I can't tell the difference between .2s NA car and .3s FI car - However I can tell the difference between 300HP and 400HP (delivered by the torque).

To get the thread back on track - I'm happy that Porsche have put out the official kit, this plus the remap will ensure lag is minimised through total engine management - which is far more sophisticated than stand alone wastegate management. Job done

R_Rated

He wants to argue with everyone in this thread and has no concern with facts or data.


Footnotes on Thread....

7.5K gets you Porsche Warrantied bigger turbos, a tune and a plastic engine cover. Really expensive for turbos... but cheap for Porsche.

Vs the 991.1 it is less money but also far less components for similar gain - which is nothing on the street

randr

I'm happy to pay the price for - two turbos, additional brake ducts, carbon fibre "plastic" cover - plus the Porsche factory engine remap which ensures all components work throughout the system e.g. anti-lag strategies, engine mapping through to PDK and PTV - E.

The price for reliable integration and plus warranty is well worth it.

I actually understand what the boost control/management is, and throttle response variability is under and off load.

R-rated no one gives a stuff about the 991.1 in this thread or frankly, from my perspective at all - this is a thread about a kit that you can't fit to your car - stop derailing a thread yet again.