997.2 Turbo S news

[Alex L]

Source: http://www.autocar.co.uk/News/NewsArticle/AllCars/247387/

Porsche's new 911 Turbo S will become the fastest and most powerful 911 Turbo model ever when deliveries start in May.
The Turbo S badge has been used twice before, on limited-production run-out versions of the 993 and 996. This time, however, Porsche says the 997 Turbo S will be a model in its own right, sitting right at the top of the current range for the final two years of the 997's production.

It has been created to meet demand from customers asking for the ultimate driver's 911, and many of the options from the standard 911 Turbo are available as part of the list price.

Power from the 911 Turbo's twin-turbocharged, 3.8-litre flat six engine has been increased in the Turbo S to 523bhp, up from 493bhp. Its torque output has also been increased by 37lb ft, to 516lb ft. Despite these increases, combined fuel economy remains at 24.8mpg.

Power is sent to all four wheels through a seven-speed PDK dual-clutch gearbox in conjunction with Porsche's Traction Management system. Wheel-mounted paddle shifters are included as standard for the first time in a 911. Porsche's Torque Vectoring system, which includes a mechanical limited-slip differential, is also standard.

The chassis is upgraded by the inclusion of the Sport Chrono package, which includes Launch Control and Dynamic Engine Mounts. These changes improve chassis rigidity, reduce vibration and help boost speed and acceleration. The Turbo S's 0-62mph time is 3.3sec, 0.3sec faster than the Turbo's. It can get from 0-124mph in 10.8sec and reach a top speed of 196mph.

Other standard features over the regular Turbo include Ceramic Composite Brakes, Dynamic Cornering Lights, sports seats with increased adjustability, 19in RS Spyder alloys wheels and two-tone leather seats.

Prices for the Turbo S start at £123,623 for the coupé and £130,791 for the cabriolet, respective price rises of £21,800 and £21,743 over the Turbo.

 

[Alex L]

Web Special available from the Porsche UK site:

http://www.porsche.com/uk/

Or click here

 

[garyw]

I'm surprised that they have launched it so early.. its normally the run out model...[&:]

So a bit of extra power (wondering where thats came from?) and a raid on the options catalouge...maybe about £21K worth??[]
Well done Porsche for once again probably pi**ing off another load of new customers who may have just ordered new Turbos...[&:]

Quite liking the two -tone look though

garyw

 

[Alex L]

Yes, the 2 tone seat look great! Very Lambo-esque

Well 30 more PS but the same torque as the base Turbo model.

Am I going crazy or when the Turbo came out wasn't 0-100 kph (62mph) quoted at 3.4s? Seems the UK site has change this to 3.5s now (with PDK and Sports+)! Perhaps to differentiate the Turbo S more?! Maybe it was just the Press cars that were suped-up with Turbo S ECU remaps?!

 

[tscaptain]

I'm not p*ssed off! That two tone wouldn't look right with red........[] I dare say the same power would be available from mine with the right re-programming but it seemed fast enough for me already. And the other "standard" features are available as options currently anyway.

 

[Alex L]

How does resale on the S model work? As normally you don't get any money back for factory options when you come to sell. Given the S comes with all those options, does it depreciate effectively faster?

ie. how do 996 Turbo and S second hand prices compare?

 

[bobfair]

Looks like a fabulous car to me. The interior has been upgraded at last and looks very nice. Looks like the DFI engine can be tuned!! Still no sports exhaust though

I could see Sir Lancerlot in one of these when he is over his Italian fling

 

[Alex L]

ORIGINAL: bobfair
Looks like the DFI engine can be tuned!!

To a limit...

According to Engineers at Weissach testing the 997tt.II Dfi engine revealed a limit of 550-570PS on Porsche engine dyno (~640whp for chassis dynos) with engines destroying themselves at this level of loading. The causes of destruction are quite fundamental: conrods and piston failures.

 

[tscaptain]

These are pushing their luck then!

http://www.speedlux.com/speedart-btr-ii-580-based-on-the-porsche-997-turbo-gen-ii/

Don't see any mention of stronger con rods or pistons in there?[&:]

 

[Alex L]

ORIGINAL: tscaptain

These are pushing their luck then!

http://www.speedlux.com/speedart-btr-ii-580-based-on-the-porsche-997-turbo-gen-ii/

Don't see any mention of stronger con rods or pistons in there?[&:]

Look how little torque increase there is for an extra 80 BHP though! Only 20Nm.

Power on the stock 911 Turbo has been increased from 500 hp to 580 hp and 720 Nm of torque.

So they are obviously trying to limit the stress on the engine. 580BHP for an old M64 engine tune would come with at least 800Nm torque.

As Toby wrote on the Rennlist site regarding the new engine tolerances:

Porsche know, Tuners haven't got a clue

The Mezger engine was raced and developed for so long that I reckon tuners got blase about limitations (like some of the Switzer 800hp on stock internals jobbies !)
I guess they may come at this like they tune VWs or Audis ie the engine may be able to take another X%, but it is mostly guesswork.

We need some destructive testing and racing to find those limits - its going to be carnage

 

[tscaptain]

Ok so we reach the limit of my knowledge of physics! How do they increase the power by 16% and the torque by only 3%? I also wish someone would decide on which units to use! Anyone have a simple explanation of the relationship between torque and bhp? All I know is that torque is the turning force and power is the rate at which work can be done.....[&:]

 

[okellyt]

TS

The Turbo S is 30hp more and 50nm more. The latter being the same as the std turbo's torque on overboost with sports chrono plus (for 10 secs)

I don't have the formula to hand but torque x revs sort of relates to power, its not quite linear and there are lots of other factors but broadly speaking that is how the two are linked. (torque is work , Power is rate of work)

So an inrease in rev limit can equate to more power even with a lower torque, a drop off of torque at higher revs can result in a lower power etc....

I am hearing different things to Alex, from my sources the VTG seems to be the source of a few problems for tuning the engine. Replacing with std turbo's a couple of tuners are running the DFI engine on destruction tests at very high powers with fair reliability at the moment. What's truth and rumour, or indeed as Mr Blair might say "ones perspective of truth" is anyones guess

I guess we really won't know until there are some tuners models out there []

 

[tscaptain]

ORIGINAL: okellyt

I don't have the formula to hand but torque x revs sort of relates to power, its not quite linear and there are lots of other factors but broadly speaking that is how the two are linked. (torque is work , Power is rate of work)

None the wiser Tom![]

 

[okellyt]

TS

Other factors being equal. If you had an absolute flat torque curve through the rev range, you'd have a lovely clean power line, increasing in line with the revs. So if this theoretical car had a peak power of 60hp at 6000rpm, then it would have more or less 30hp at 3000rpm (lots of sources of losses come in here so its not quite true). Then 45hp at 4500rpm etc.

What makes it difficult is that the torque output has a curve ie it varies with revs and this in turn effects the power curve which then stops being a nice straight line with revs.

If you stick a car on a good dyno system reality is very different - once the engine is in the car you restrict the engines air intake and exhaust and then load up the engine with connection to the drive shafts etc this dramatically effects the cars power and torque curves. You've just put an engine into a significantly lossy system

The curves then go all over the place, as there are a number of compromises. In addition you get various steps and drops as different valve timings etc come into effect (with mechanical systems its all spiky in reality unlike the smooth curves the sales manuals show you). The bit I don't understand is there seems to be a compromise to be reached between low end (revs) with a lot of torque and high revs with a lot of torque (basically you can't have both, so there is a trade off) - so compromise top end power for mid range power (& acceleration) or comromise mide range power for more top end power............

One of the reasons the 997 tt is much faster than it feels mid revs is that it has an almost flat torque curve over several thousand revs, so power rises with revs in an almost linear fashion giving very consistent acceleration - Humans notice sudden changes in acceleration more than linear acceleration, so the car ends up going faster than we think. However the torque drops off toward the red line, so peak power is reached earlier - this gives the comment given in a lot of magazines to the effect that there was no point running the car to the red line.

So why would a car produce 10%-ish more power with only a 3% torque increase - Well if peak torque co-coincides with high revs you get a higher maximum power, so then it'll accelerate hard near the red line but not much might be going on at lower revs. You could raise the rev limit on the engine and keep a relatively high level of torque output at this point, or you can do lots of clever things to reduce losses at high revs optimizing what you already have. The latter point being one that Porsche obsesses about with the GT3

In the case of the modified car it has 70nm more than the normal car, which has 650 - except for on over boost with sports chrono where, for 10 secs you can get 700nm. The over boost will likely have its peak torque at lower revs so it does not increase peak power. Whereas the torque curve is likely to remain higher near peak revs for the modified car and therefore you get the power increase.

 

[garyw]

So it looks like the S revs slightly higher and the extra power is just via the ECU...

garyw

 

[tscaptain]

Thank you Professor O'Kelly[]

 

[Alex L]

ORIGINAL: okellyt

I am hearing different things to Alex, from my sources the VTG seems to be the source of a few problems for tuning the engine. Replacing with std turbo's a couple of tuners are running the DFI engine on destruction tests at very high powers with fair reliability at the moment. What's truth and rumour, or indeed as Mr Blair might say "ones perspective of truth" is anyones guess

VTG's?! Plenty of tuners offer upgraded VTGs for the 997.1 Turbo - mostly for Stage III cars. Why would the same VTGs in the 997.2 Turbo now be an issue?!

 

[okellyt]

Alex

As I said its what i am hearing, buyer beware with rumor and all that - however what is being said is not that the VTG's per se are problematic but if you want consistent higher power outputs without straining existing components they are tending to have to use their own adaptations, notably a bigger turbo unit (VTG or otherwise). Even the example quoted earlier indicated that their 680bhp follow on conversion required a change to the standard VTG to a bigger one........This is no different from the Gen1 TT engine, where most of the big power hikes replaced the standard Turbo unit with a bigger one and for really high outputs they abandoned VTG for two traditional Turbo units.

A lot of this is down to resources available to the tuners, they don't have the volume of turn over or cash reserves of Porsche but still can't afford to risk expensive failures on their high power conversions, so will revert to what they already know - established, less complicated and cheaper parts rather than trying to design and custom build an even more complex and expensive VTG replacement part.

 

[Porker993]

All I can say is, Wow. What a car ! I am in the fortunate position of not being ***ed off as I shall be unable to afford one for about 10 years !

 

[okellyt]

Mark

I have to agree with you. It comes with all the turbo options I would have ticked as standard - is a little bit cheaper and has the extra power and torque thrown in for free[]