True, but only for humans because the high humidity inhibits perspiration.

I don't know about yours, but my 911 doesn't sweat, so that effect is irrelevant.

In fact, the high humidity reduces power because the water vapor displaces air, reducing engine power and, therefore, waste heat.

 

Here's some thinking on the torque, taking the extreme case for a 991.2 3.0 L tt. The GTS engine is rated 550 N-m (405.659 ft-lbs which as an engineer I call 406). The ECU is set to go into limp mode at 700 N-m (516 ft-lbs). Why so high? The answer is Porsche allowed extra torque to enable launching. At 6000-6500 rpm launch, the engine has high torque and high power, but there is an added factor: rotating mass of the engine crank & portions, cams alternator and belts, and flywheel, and the total of those is considerable.
Here is what I'm thinking about tuning and ECU recording of peak torque.
Even if you were to very aggressively tune for higher power and much higher torque, the torque limiting would not likely come into play without launching. And the recording of peak torque by the ECU never appears that high at full throttle with a tune, without launching. So the peak torque recorded would not appear to be excessive, unless maybe when launched.
Thoughts?

 

👍 I will place my order in a few weeks, when we return.

 

Kiril had 450 ft lb at the wheels on a mustang dyno at 3k rpm in 4th gear. And he has a manual. Thats way over 516 crank. Keep thinking what u want but the 991.2 pdk will be the weak link eventually on this platform. 992 goes up to 850 Nm and will be more robust except I bet its untuneable.

 

The PDK may be the weak link, torque-wise, but it's unlikely it will break with a JB4 tune, especially if not launched. JMHO.

 

I agree completely that the jb4 will be much safer that a flash. If u remember on dyno day my GIAC flash also had a tabletop tq curve down low to protect the tranny. Vs the cobb which just rocketed to pk tq. Jb4 is going to be using stock accessory tables like aatish said. Youre not gonna exceed any safety parameters guaranteed.

 

You are talking PDK in regards to launch, right? And it and the manual have the same max. torque ratings?

 

According to the technik manual yes 406 ftlb for both. Its the same transmission except for the clutches. Gearset from the 991.1 turbo is actually bulletproof. The clutches are not that robust. The manual is also a dry clutch and more susceptible to heat. But overall i think the manual is more solid

 

The PDK will see higher torque than the 406 ft-lbsa, because of the harder shifts and launches. Full 406 torque at WOT is less than during launched and shifts. Most manuals are never launched as hard a PDK. That rotating mass upstream of the PDK clutch at 6000+ rpm adds significantly to the peak torque during launch.

 

The ECU doesn’t know how much torque is being made so can’t impose torque limits...it also means that the PDK box can’t increase clutch clamping force correctly, which is another reason why a flash is a better engineering solution.

Ignition curve can’t be optimised, increasing boost and fuel pressure but using stock ignition curve is not optimal.

It would be really easy to write code that would tell you if a piggy back is in use, others have done it and I wouldn’t be surprised if Porsche have. As a result quite taken aback at the assertion from the vendor that the device can never be detected. Would that be admissible in court should an engine fail and warranty be rejected due to piggy back use?

 

PDK logs tq and other logs. In the BMW world its completely detectable IF they dig far enough (ie the region rep in contact with Germany). If its a spun crank or turbo in the BMW world, its gonna be a fight. With Porsche I'll assume the same. Audi have a tool for it (Piggy's even after removal)and Audi dealers are the most strongly encouraged of ANY car manufacturer to flag those cars.

 

For me it should be assumed it's detectable and if there is a major breakdown they can attribute to the tune then suck it up and take care of it.
So with that it's really about picking the best tune for what you want from your car instead of trying to sneak under the radar.

 

We have ways around that to optimize and change timing

For the tuning to operate properly the ECU can't be aware it's being manipulated or you'd throw a fault code. We're not looking to be your partner in warranty fraud. If you damage something operating the vehicle outside of the factory specifications you should pay for the repairs. That said, the JB4 is a diagnostically invisible tuning solution.

-Payam

 

Code as in software, not as in a fault code. If you really think that no code could detect what is going on you haven’t understood the capabilities of modern engine management systems.

Do you give a full warranty for any drivetrain failures attributed to having the device installed? If it cannot possibly be detected then this would surely cost you nothing?

 

ran out of popcorn halfway thru this thread but it seems that a proper ecu tune is much better than jb4 especially if there is same warranty risk