Can't really look at the 996 Turbo engine or the 997 Turbo engine (GT1 or the new 9A1) vs. the engines in the NA cars a difference at a time. One has to consider the whole package.

As we 996 Turbo and the early 997 Turbo owners know the Turbo engine is based on the GT1 engine while the NA cars' engine is based on well the M96 engine.

These are very different engines. The GT1 engine had to produce competitive amounts of HP and do so reliably over a goodly span of time. It is detuned and some less expensive parts are used -- steel rods/rod fasteners vs. titanium for the GT1 for one thing. The GT1 engine may have had steel crank and layshaft gears while the Turbo engine's layshaft gear is IIRC aluminum. Also, of course there's a huge difference in the Turbo engine and its crank to layshaft drive and the layshaft to cam drive vs. the M96 engine and its IMS arrangement.

I do not know if the GT1 engine is an open deck design or closed, but the M96 engine is an open deck. (The new 9A1 engine is a closed deck engine.)

Even if an automaker released two engines based on one basic engine platform one engine NA and the other turbo-charged there are (should be if the turbo-charged engine done right) big differences internally. Compression ratio almost certainly will be lower. Camshafts have different profiles and different lifts. Timing will be different too. Points at which variable timing is activated and by how much and this applies to the variable valve lift feature of VarioCam Plus almost certainly will be different. The turbo-charged engine -- at least this is the case with the 996 Turbo -- can be fitted with wide-band O2 sensors to provide more precise fueling (critical that a turbo-charged engine running on boost not be fed too lean a mixture!). Along this same line the Ecu and fuel/timing maps are different, knock control may be more agressive, and of course there's boost control (variable vane turbos on the 997 Turbos). Fuel injectors may be larger. Intake system larger on a Turbo engine and this almost certainly means the air filter is larger.

The turbo engine may run a bigger oil pump, have a larger oil supply (or in the case of the Turbo engine be dry sumped compared to its NA brother which has an integrated dry sump). The turbo charged car can be fitted with almost certainly higher capacity fuel pump, bigger radiators or have an extra radiator or a bigger oil cooler, run a cooler thermostat, have better aerodynamics to help direct more cooling air through the radiator duct openings, and so on. The radiator fans and engine compartment fan on temp thresholds may be set lower and the fans may have more stages (speeds).

By my observing coolant temperature in real time my 996 Turbo runs quite cool even in warm weather that would have the coolant in my 02 Boxster 10 or more degress hotter and the radiator fans running. The Turbo's aerodynamics as it relates to air flow through the radiators (at least) is much better than that of my Boxster.

Done right a turbo charged engine and a NA engine can be quite different (along with the car platforms both are fitted in) though from the outside the engines (and the cars to the casual observer) look quite alike.

Sincerely,

Macster.

 

Well put macster.

 

I second that. I knew there had to be more to it than just slapping on a couple of turbos.

 

It really isn't THAT much more than a loaded C4S. That AWD system probably isn't cheap. The extra plumbing and turbos/intercoolers/electronics cost a bit. Wider track and bigger wheels, etc.

However, at the end of the day, the price bump is there simply because they know people will fork out the money to be one-up on their neighbor.

 

Sorry, the proper flat 6 99x Turbo engine ... The one with a true dry sump and a history dating back into the 80's... Has set the bar pretty high ... IMHO, the finest production engine ever to come out of Porsche. Period.

Everything else is just a cost reduced commodity design.

Of course, I could be wrong....Boolala is the RL expert on this topic.

 

There's something to your observation regarding the price bump (difference).

No one needs a Turbo with mega hp and such. Many cars can deliver much cheaper and just as reliable transportation as that provided by the Turbo. The C4S comes darn close to providing the same Turbo ability to cover loads of miles in comfort and safety. And in most places one can't use the but a portion of the C4S's performance.

It is the want over and above the need that has some bearing (probably more than we can imagine) on the price.

The price of something is not its cost to make with a reasonable profit added on, the price is what the market will bear to pay which in the case of the Turbo I would hazard a guess is way above the cost to build the car with a reasonable profit added on. Way above.

But obviously, Turbo owners are willing to pay.

Sincerely,

Macster.

 

Some of the Porsche techs I speak with once in a while are almost fulsome in their praise of and their admiration of the Turbo engine. Some believe the Turbo engine is the only engine of recent vintage worthy of the 'Porsche' name.

Until the 9A1 engine. These same techs are as thrilled with the new 9A1 engine as the Turbo engine. It is not out of the realm of believability to believe that Porsche has in the 9A1 engine produced a superb engine one that doesn't diminish the Turbo's rep but brings with it or will over time, it own rep and ultimately outshining the Turbo engine.

I mean as good as the Turbo engine is if Porsche engine designers can't surpass that engine's design -- and smart/economical commoditization of the new engine to make it cheaper to make, reduce the amount of engine parts dealers are required to stock, make the engine easier to service/work on is just as important as bumping the hp/torque numbers to new highs -- given all the time they've had to study/learn/etc while the Turbo engine (and the NA engines) have been in service, then they're in the wrong line of work.

Sincerely,

Macster.

 

Time will be the final judge...BTW, are they racing this new engine yet?

 

There is more to an engine's appearing in race cars than its performance or suitability, etc.

I mean, sure, the engine may be crap, ill-suited for racing.

But I can easily imagine there are other reasons why a newly introduced engine is slow to appear on the track.

Race car owners and their race teams/techs/etc and the shops and techs at the shops they use have alot of history with the current engine offerings. They have spare parts, or aftermarket parts that have proven themselves over time.

The mechanics can remove, disassemble, reassemble, install the current engine very quickly with no mistakes, time after time.

No race car owner wants to be the first. If the engine's crummy and cars with the new engine do poorly the car owner can lose sponsers in a heart beat. They'll likely go to his competition. Ouch.

Also, I suspect Porsche has some stock of the old engine it wants to get rid of before it obsoletes the old engine and any stock of spare parts it has with the release and official sanction of the new engine.

Lastly, I'm not up on what it takes to get a new engine certified for racing. Most race classes are not the old run what ya brung variety but have rules on what engines are recognized and allowed. If I'm right then it takes time and money and given the economy is still not very robust Porsche and car owners are probably reluctant to spend that money right now.

Sincerely,

Macster.

 

 

Of course he is.
He is the author of the thread on this topic, with the most views (by a 2 to 1 margin) since this forum was founded.

If that doesn't make him an expert, I simply do not know what would...

https://rennlist.com/forums/997-turb...new-turbo.html

 

The GT2RS. When Porsche built a hard core, top of the line world beater they went old school with a real dry sump and a 6 speed. That speaks volumes to me.

 

Not exactly, if the new engine was 'all that', then teams would be using it before it's even released to the public. There are plenty of teams that would spend whatever is required to win, trust me.

 

Can you? sure...it increases the combustion chamber volume.

However, this greatly reduces the quench, which actually increases the likelihood of detonation, despite the lower compression.

A sort of half-assed way to do it.

 

yes, some people argued they were the same, and they aren't. Sure the basic architecture is the same, but there HAVE to be significant differences.