What Engine For the America GS?

Robert Linton · 04-12-2009, 03:53 PM

As we begin the R&D for what was to be a normally aspirated 4.0 liter engine, the question is should we go to a smaller displacement turbo instead?

demonfish · 04-12-2009, 03:56 PM

how about smaller twin turbo... then stick with the 3.6...

tis what i'd do, funds allowing.

Robert Linton · 04-12-2009, 03:59 PM

That is what I am thinking.

JasonAndreas · 04-12-2009, 04:52 PM

Quote:

Originally Posted by Robert Linton

should we go to a smaller displacement turbo instead?

Normally aspirated 3.6L with a 13k RPM red line and it has to have the potential to remain a daily driver.

ilko · 04-12-2009, 05:10 PM

I like the idea of a NA 4.0L. It's very different from everything else out there (just like the car).

Colin 90 C2 · 04-12-2009, 05:11 PM

I'm with demonfish. 3.6L, 9.0/1 compression, 2-gt28rs turbos, conversion to mass air. And you may want to start with 993 h/e's.
I have the complete plan, just not the funds to execute.

tony.t · 04-12-2009, 05:58 PM

In order of preference;
NA
centrifugal supercharger
turbo

turbo solutions always seem to run up against how efficient the intercooler is. For an equal hp level NA always seems to be the more elegant solution.

DAVISRILEY · 04-12-2009, 06:05 PM

Quote:

Originally Posted by JasonAndreas

Normally aspirated 3.6L with a 13k RPM red line and it has to have the potential to remain a daily driver.

Well, what about the 4.0l with a 10-12k redline, and daily driver capabilities? Can you imagine how either of them would sound?

Geoffrey · 04-12-2009, 06:10 PM

Given your quest for lightness, I would stick with a large displacement N/A engine like you originally planned. The turbo components add about 100lbs to the car in the wrong location. Having had both, I much prefer a non turbo car for real world driving and I'd wonder how well the Tip trans would do with a turbo engine. Just my $.02.

Robert Linton · 04-12-2009, 07:25 PM

But Geoffrey, think of the beautiful Secan intercooler.

Geoffrey · 04-12-2009, 07:35 PM

No doubt, they are beautiful. I've done so many MoTeC Turbo cars and I always return to liking the simplicity of the N/A engines.

Cupcar · 04-12-2009, 08:49 PM

Lots of people have smaller displacement air-cooled Turbos - there are only a few air-cooled 4.0 Liter 911s out there and none factory built.

Not to mention the throttle response and light weight of the N/A engine is hard to beat.

earlyapex · 04-12-2009, 09:21 PM

I always prefer a NA motor to a turbo or SC'd one. They sound better to me and I prefer their driving dynamics.

tony.t · 04-12-2009, 09:25 PM

Quote:

Originally Posted by Robert Linton

But Geoffrey, think of the beautiful Secan intercooler.

but unless you are able to come up with a better intercooling solution than the Secan you have hit a celing at which no more power is readily available.
No doubt the turbo installation can be made lighter than 100kg though.

ltc · 04-12-2009, 09:39 PM

I had simply assumed the car was already equipped with M64/GT1 derived powertrain with KERS.

04-12-2009, 03:53 PM	#1
Robert Linton Addict Rennlist Member Join Date: Mar 2002 Posts: 1,821	What Engine For the America GS? As we begin the R&D for what was to be a normally aspirated 4.0 liter engine, the question is should we go to a smaller displacement turbo instead?

04-12-2009, 05:10 PM	#5
ilko Agent Orange Rennlist Member Join Date: Jun 2006 Location: The Highest Point on Manhattan Posts: 10,110	I like the idea of a NA 4.0L. It's very different from everything else out there (just like the car). __________________ Current: 993 Carrera 4S - my mistress with wide hips B7 S4 Avant - just got it!! Past: 964 RS America #17 - supercharged flame thrower 964 Carrera 4 - met its match at Lime Rock 944 Turbo - 32K mile garage queen

04-12-2009, 05:11 PM	#6
Colin 90 C2 Addict Rennlist Member Join Date: Jun 2003 Location: Delaware Posts: 967	I'm with demonfish. 3.6L, 9.0/1 compression, 2-gt28rs turbos, conversion to mass air. And you may want to start with 993 h/e's. I have the complete plan, just not the funds to execute. __________________ 90 C2-GP White/Black,Gemballa primary muffler, drilled airbox,K&N, Roock/Bilstein, Lwt Flywheel, no drips 254 RWHP

04-12-2009, 06:10 PM	#9
Geoffrey Addict Rennlist Member Join Date: Dec 2001 Location: Kingston, NY Posts: 8,183	Given your quest for lightness, I would stick with a large displacement N/A engine like you originally planned. The turbo components add about 100lbs to the car in the wrong location. Having had both, I much prefer a non turbo car for real world driving and I'd wonder how well the Tip trans would do with a turbo engine. Just my $.02. __________________ Racetek Engineering 93 C2/RSR 3.8 92 C2 Coupe 89 911 Turbo 91 944S2 Club Sport 87 924S

04-12-2009, 07:35 PM	#11
Geoffrey Addict Rennlist Member Join Date: Dec 2001 Location: Kingston, NY Posts: 8,183	No doubt, they are beautiful. I've done so many MoTeC Turbo cars and I always return to liking the simplicity of the N/A engines. __________________ Racetek Engineering 93 C2/RSR 3.8 92 C2 Coupe 89 911 Turbo 91 944S2 Club Sport 87 924S

04-12-2009, 03:56 PM	#2
demonfish User Join Date: May 2007 Location: Birmingham, UK. Posts: 963	how about smaller twin turbo... then stick with the 3.6... tis what i'd do, funds allowing.

04-12-2009, 03:59 PM	#3
Robert Linton Addict Rennlist Member Join Date: Mar 2002 Posts: 1,821	That is what I am thinking.

04-12-2009, 05:58 PM	#7
tony.t User Join Date: Feb 2009 Posts: 25	In order of preference; NA centrifugal supercharger turbo turbo solutions always seem to run up against how efficient the intercooler is. For an equal hp level NA always seems to be the more elegant solution.

04-12-2009, 07:25 PM	#10
Robert Linton Addict Rennlist Member Join Date: Mar 2002 Posts: 1,821	But Geoffrey, think of the beautiful Secan intercooler.

04-12-2009, 08:49 PM	#12
Cupcar Addict Rennlist Member Join Date: Jun 2001 Location: California Boardwalk Posts: 2,228	Lots of people have smaller displacement air-cooled Turbos - there are only a few air-cooled 4.0 Liter 911s out there and none factory built. Not to mention the throttle response and light weight of the N/A engine is hard to beat. __________________ "It all started when I began looking around and just could not find my dream car. So I decided to build it myself” - Ferry Porsche 1969 912/5, first Porsche (Gone), 1970 914/6 with factory GT conversion kit see Excellence, May 1993 (Gone ), 1983 944 driven from new daily into the ground and walked away from , 1992 911 Carrera Cup USA Edition see Total 911, April 2008 (Gone ), 1995 993 RS Clone in progress

04-12-2009, 09:21 PM	#13
earlyapex Addict Rennlist Member Join Date: Jan 2004 Location: Salinas, CA Posts: 2,946	I always prefer a NA motor to a turbo or SC'd one. They sound better to me and I prefer their driving dynamics. __________________ http://jwemotorsports.com/ Eric 1978 911SC, PRC/PCA spec 911 1993 964 RSA #33 Lifelong copilot

04-12-2009, 09:39 PM	#15
ltc Super Moderator Needs More Cowbell Lifetime Rennlist Member Join Date: Mar 2002 Location: Fortress of Solitude Posts: 27,713	I had simply assumed the car was already equipped with M64/GT1 derived powertrain with KERS. __________________ ...Lewis

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