fxz

Euro dealers back to the future?

https://rennlist.com/forums/997-gt2-...announced.html

City

Eduardo thanks for the feedback!

I still think Porsche won't release a 991.2 GT3 or GT3RS and will go straight into GT2 and GTRS to finsh off the 991.2 face-lift. The N/A engine is done!

So this makes sense finish the 991.1 off GT3 with a limited edition. How many worldwide do you think will make production?

Zeus

Why is everyone so quick to give up hope on the NA engine?

I'd take a lightweight, high-revving NA engine that costs $250,000 for Porsche to build for one of their future sportscars any day over a smaller displacement engine that needs more batteries to make up the power difference.

Someone, somewhere on the McLaren forums even posted that the 4.6 V8 in the 918 weighed significantly less than the TT 3.8 V8 used in every McLaren.

Z356

City: We will see on the predictions.

First of all, the '4.4' Limited Edition could be a .2 991 gt3 RS with
face-lifted features. So not necessarily a .1 991 gt3 RS (MY2016),
although it could be easily that as well. It all depends on the 'sell by'
date on the engine due to impending regulations that will affect
that naturally aspirated motor!



PAG did 600 of the .2 997 gt3 RS 4.0 as a Limited Edition.
I don't anticipate it would be anything less than that...and
perhaps a cool 991 of them to remember this last model
by its chassis - a la 918 of 918!




Saludos,
Eduardo
Carmel

karimgt3

Thanks for the info Eduardo!

4.4L flat 6 doesn't sound right to me though.. How thin will the cylinder walls be? And it will surely rev less aswell? Petevb?

plasticsdoc

Looks like 913 to me and the dealers think that also ?

Petevb

Possible in theory, unlikely in practice.

The 911's cylinder bore spacing has been held constant since the first 2.0 liter engines at 118 mm. Initially the bore was just 80 mm in diameter, so there was 38 mm of space between bores for metal, fins and air cooling. That decreased over time and the engines grew. By the 997.2 GT3 RS pistons were up to 102.7mm, so the gap was down to 15.3 mm using pressed in steel cylinder liners. The aftermarket goes larger still, to 104.5 or even 105.4 mm, but the cylinder walls are getting very thin.

The resulting 12.6 mm gap still isn't the technical limit. By casting the cylinder liners into the block instead of pressing them in, Chevy achieves just an 8.8 mm wall thickness on their LT1, just enough for two layers of metal with coolant between them. Thus while it would take more effort than I suspect Porsche is willing to put in, a 107mm bore with the current 81.5 mm stroke for a resulting 4.4 liters would be theoretically possible. Achieving 4.4 liters through stroking alone would cut peak RPM to ~8000- this seems highly unlikely. The best might be a combination of stroke and bore (105mm bore x 84.5mm stroke, 8500 redline) but it would be very unlike Porsche to make so many custom parts.

I'm not sure any of this dance is required regardless. It was pretty clear when Porsche released the 991 RS with 500 hp that they were leaving room for another model above it. The redline increase and head design would lead you to expect a ~525 hp rating with the 4.0 all else being equal. I'd probably just do that if I were them, or at most go to a 4.2L (104.5 bore w/ 81.5 stroke) and 550 hp. That'd be far easier, and would seem more than enough to sell a bundle at a significant premium to the RS.

NateOZ

4.1/4.2L was the rumor I heard last year, seems the most likely outcome to me as well.

neanicu

Why not just put a 5.0L flat 8 in it with 600 HP? I think it should fit,it's not that much longer. Ups Did I just say that out loud?

Serge944

Guys, even a 4.6 liter GT3 has been done. Accomplished by using an 88 mm stroke (stock 996 was 76.4)!! Way back by Koro.

http://www.autobild.de/artikel/koro-4.6-rm-s-45527.html

ipse dixit

Yes, been done.

But marketable? Profitable (from a usage versus warranty/repair standpoint)?

Serge944

You and I both don't know the answer to that question. But Porsche engines have no problem blowing up even at stock displacement!

STG

997rs4.0

I guess we all know that 991.2gt3 will have the 4.0l RS engine. And I'm on the list for the 4.2l (525hp) 991.2RS. I'll buy it if it doesn't come with a Panamera interior!

dark knight

I remain confused at the purpose of small run limited editions when they already cannot fill demand for regular GT3s and RSs