GrantG

They are not going to gain 6% power at 3% higher revs without adding displacement...

With the Variocam on both intake and exhaust now, there really isn't much trading of low-end to create more power on high-end anymore.

Alan Smithee

^ You are assuming the ECU is max'd out and numbers are accurately being reported/quoted for the GT3, no?

Guest89

Thank you for underscoring the point which I initially made.

robmypro

4L = 244 cubic inches. The thought of getting this much horsepower out of 244 cubic inches is astounding.

GrantG

No, I'm just assuming that the safety margins for the RS would need to be similar to the GT3 and that they would need to make 30hp more (even if both numbers are conservative - it would be too embarrassing to have the actual difference be only 10hp on the dyno, because the GT3 already makes 515hp...)

Alan Smithee

I guess what I'm saying is...I agree with Dante on a 4.0 with ~530 @ 8,500 RPM; I expect both engines were developed simultaneously, and the GT3 was dialed back to 500 via ECU, so no need to add displacement or crazy RPM to get more power out of the engine.

fxz

Then easy to tune GT3 to 530 HP

with a dundon catless easy 560HP

4L 560 hp sounds crazy with redline 9k max rpm

btw not to mention piston speed stroking

Brosef

amen

GrantG

That would be really sad (and unprecedented) if they electronically neutered the GT3. Porsche has never done that to a GT car before (GT4 has restrictive intake and exhaust, but not actually stifled like the 981.1 Boxster was compared to the Cayman and 3.4L S to 3.4L GTS to create an artificial difference, for examples).

And I do not believe this is what happened...

MaxLTV

That can very well be the case. Look at the Dundon headers development thread - a lot of power was unlocked by changed header design, but it then runs into software torque limiters. Just removing limiters via tune allows for more power. It's not a gigantic difference but enough for a one small step. But who knows if they have done it for marketing reasons or to reduce reliability risks.

Alan Smithee

I fully expect AP to regale us with some elaborate explanation as to the magic involved with the upcoming RS engine power increase so that it will not appear to be an ECU change. We'll see...to me it just seems too convenient that, with all of the changes to the new 4.0, it currently makes exactly the same numbers as the old one.

CAlexio

Try just adding a Cobb to the gt4 engine without any other mods, and then tell me if you still think it wasn't ECU hobbled in some way. You think VAG engineers who hid diesel emissions from the world, who put out perfectly incremental and symmetrical power, torque and Nurburgring lap time improvements... aren't messing with ECU's?... come ON man!!!

Drifting

Exactly. Very suspicious for the new Motorsport GT3 engine with new architecture and all these new improvements described by AP, to make exactly the same HP and exactly the same torque as the 991.1 RS, and 997 RS 4.0.

I think the .2 GT3 is being electronically neutered a bit, and Porsche can just release that neutering for the .2 RS, and bam the .2 RS gets 525 hp out of basically the same engine.

GrantG

I also think the numbers are too convenient (and have said so repeatedly), but my conclusion is different. I just assumed that they didn't want to upstage the 911R and 991.1RS with better numbers, but that independent dyno pulls would reveal the .2 GT3 to be the stronger motor (in torque and hp).

Maybe I'm being naive, but I assumed they wouldn't do something as cynical as not opening the throttle all the way (which is how they cut 10hp from all the Boxster versions of the 981.1 compared to the Cayman) on a GT car.

All production cars are tuned with a large safety margin (to run on crappy fuel, etc.) and so it's no surprise that the GT4 makes more power with a tune alone (reducing the margin for error in ignition timing, etc.). But, so does every other Porsche model.

At 125hp/L before ram-air, even the conservative factory rating doesn't leave too much power on the table (if there was funny business, there certainly wasn't very much of it...).

Just in time

At 530 hp would mean specific output of 132.5 hp/L. That folks is pretty heady if the engine is going to last 100k miles. Someone mentioned 140 hp/L. Phewwww!