ITT : Alex learns about porsche engines

[John Milmont]

I kinda have lost all faith in rotary motors which is explained very well here: Hitler reacts to the Rotards - YouTube ...

Whats the surplus like of 3 rotor cosmo engines these days? I remember about about 8 years ago they were pretty expensive. You had to get one of dubious quality from a junk yard which would require a rebuild. Plus all the porting work and aftermarket turbos. Who would run a stock 20b?

 

[Paul Osborn]

I knew you guys would like that.

G1 Dave.

 

[Graham]

The 996 and 997 Twin Turbo and GT3 engines are based on the guts of a GT1 engine developed by Porsche for Endurance racing. These engines are NOT to be confused with the N/A offerings of the same model, which have a different crankcase etc.

600 BHP from a TT should be relatively easy, and not cost the earth. A couple of bigger Turbo's, a free-er flowing exhaust, 100 cel CATS and a re-map should get you there, and be very reliable too...

 

[domtoni]

Again to confirm what I said earlier and what Gravy is saying, avoid a 996/997 engine in its standard form. The watercooled turbos or GT3 motors are based on the old air cooled engines of years gone by. And they are strong.

 

[Dusty]

I can provide some input. I'm normally a vette guy, but recently picked up a 620 horse 2003 Turbo on the cheap. I got the whole car with a Sachs stage 3 clutch/flywheel, Recaro eglass backed seats, lighter battery, 5 point harnesses, upgraded zero clearance turbos, intercoolers and complete engine overhaul, plus GT2 gears in the G50/04 for a competitive price.

You could get a complete motor from a salvage yard for around 12-20 grand plus the EVOM upgrade to 600hp is going to run around 10-15 grand, depending if you install yourself or not. Turbos by themselves account for most of the price. You won't necessarily need to upgrade intercoolers, and EVOMs claim factory motors can handle 750 hp until you need stronger rods, pistons etc. Porsche makes well built motors with forged internals. I must warn you complete turbocharged motor weight is around 525lbs. Good news is that Porsche has been engineering motors with turbos for a long time. So these motors are spot on.

A naturally aspirated say GT3 911 you can get around 550bhp by boring the motor out to 4.5liters, but that is ridiculously expensive. Just boring out to 4.0 like the new GT3RS is like 30 grand on top of the cost of the base $30k motor taken out of a 996 or 997 GT3. You might as well buy some superlight Cosworth IRL motor for that price.

I kinda of like pushing 1.8bar pressure in a combustion chamber, as long as the internals can handle it. Viper and Vette motors..I prefer big nasty cams and ported heads. The kind where no one will tailgate because you'll blow out their eardrums. Mmm Corsa extremes and Borla XR-1s. Perfect for the street.

Yes I would suggest a Porsche turbo, preferably water cooled. Air cooled is a bit of a misnomer as those use tons of oil to keep temps down. But I still think lack of water cooling limits horsepower heat that can be removed, ultimately limiting horsepower output. Somehow I don't think the air cooled 4.5 flat twelve in the 917 lasts long. Single piston two stroke dirt bike motors and low output motorcycles.. sure air cool them. Admittedly I applaud Porsche for making their engine in a flat/boxer config to maximize cooling area much like a CPU in a computer...but the days of leaky radiators and crappy seals are far gone. But they keep the center of gravity or centroid of mass lower.

Overall I respect all engines as they were designed and built with a certain purpose in mind..it's finding the one that matches your needs.

One last tidbit..I get 35.6mpg (avg, not instant) highway going 75 in the 996TT..food for thought. Take that Prius drivers.

 

[Dalton Veitch]

I agree that different types of engines suit different purposes, and have been developed differently to specific directions and longevity (or not).
I like air cooling, as the heat is going to the air one way or another anyway. And you need oil in the engine, so why introduce a crap medium like water?
I agree that sealing, water radiators, etc. are better now, but I've still parked my family car at a shopping centre only to be surrounded by a sea of coloured coolant as a part of the water cooling system let go. Water boils away at a low temperature, and in modern cars that run the engine hot (for emission limitation) it is only kept in check by the pressure. Any leak in the system, pressure released and puff, your coolant boils off. It also corrodes everything in contact, especially with all the alloys now used, only artificially kept in check again, via additive inhibitors. What a poor medium for such sophisticated use.
Now I don't know if the 917 engine had a shorter life than the water-cooled engines in the competitors (I suspect not), but I admire Porsche. Whe people told them they couldn't get high power out of an air-cooled engine they showed this advice was nonsense and achieved it. When they were told you couldn't have a quiet air-cooled engine, such as in the 911, they developed one. It could accelerate away at full power and standing behind the car you could only hear the tyres on the road. People say a lot of things that they imagine are the case, but proper engineering can achieve many things. End of my rant. Some things are just plain enjoyable, irrespective of the engineering, such as the exhaust sound of a nicely tuned V8 (listen to the gear shifts of Steve McQueen's Mustang in the old movie Bullit).

 

[Alex]

Ya know, this thread does not make Alex all warm and tingly inside

Yea, okay, you can make 500-600hp in your porsche engine, but then I log onto yellowbullet and read about BBFs/BBCs making 1,000+ft-lbs.

If only a bigblock would fit I'd be in heaven....I wonder if you can cool a 700cid bigblock w/o a radiator, hmmmmmmmmmmmmm.

On the plus side though, at least 99x's don't sound like ass running straight pipes....unfortunately you just can't beat that bigblock mega cam lopity-lope-lope sound.
http://www.youtube.com/watch?v=bSrYVjkqrUM
vs
http://www.youtube.com/watch?v=AkBUvbX1MAM

 

[Ruth]

unfortunately you just can't beat that bigblock mega cam lopity-lope-lope sound.QUOTE]

For you maybe.

For me, that sound MIGHT be okay in a 60s or 70s era muscle car, or your Cobra, but seems completely out of context in a modern sports car. We're working hard to have ours sound as little like that as possible.

 

[Roger]

unfortunately you just can't beat that bigblock mega cam lopity-lope-lope sound.QUOTE]

For you maybe.

For me, that sound MIGHT be okay in a 60s or 70s era muscle car, or your Cobra, but seems completely out of context in a modern sports car. We're working hard to have ours sound as little like that as possible.

Yep. For me, the sound of an LSx at idle is just plain nasty. Hopefully the Coyote is nicer. A couple of turbos should sort out the power lower down the rev range too.

I have to say that I'm addicted to the turbo kick. I know full well that it's less easy to control on the track, but it make me :wideeyed:.

Unfortunately, I'm still a garage door and kitchen remodel away from being able to build a car. If only work didn't get in the way so much.