elanderholm

carrera GT motor:
452lbs 605HP
discuss...

EuG

Nm - found it.

LSs1Power

The Carrera GT HP is underrated big time. Peak HP happens at 8000 RPM showing 575rwhp and peak TQ occur at 6000 RPM showing 411rwtq. As we know the GT is rated at 605HP and 435TQ. Assuming a 15% (10% on a Dynojet) Drivetrain loss since the engine is on top of the wheels it should dyno around 515rwhp and 350rwtq. So we can see that its underrated big time.

I have the dyno on a vid and for some reason the screen shot didnt really work to post it. So im going to write down the RPM VS HP and TQ.

These runs were made on a Mustang Dyno (Usually shows 5-9% lower than a dynojet).

RPM RWHP RWTQ
2600 120 250
3400 200 310
4200 300 365
5000 350 395
5800 450 400
6600 505 405
7400 555 400
8000 575 395


By the way the V10 engine in the Carrera GT weighs 472lbs based on the information i saw.

So i honestly think there is no comparison between the LS7 and the Carrera GT engine unless you want to tow something lol.

slwhite

This is a case where the complexity is actually worth something. The Carrera GT engine is a sweet mill.

Baldturbofreak

something about that wounded coyote howl the 54deg 10's make.

Verrückt

slwhite,

I agree 100% with everything you've wrote on this page.



I don't have the exact Corvette numbers handy, but I know typical automotive validation tests are in the "hundreds of hours" realm.

I've dealt with midrange and heavy duty diesel engines that my customers have run on the dyno for around 10,000 hours at load. Think about that a second. Even after that, the engines till had much useful life left in them.

LSs1Power

Im working on a very nice dyno comparison between great engines (Carrera GT V10, M5 V10, Murcielgo V12, Gallardo V10, LS7, AMG 55 and 65)... I will just start another thread with it when im done.

The results are really interesting

Verrückt

See, you can't just say "less parts equals more reliability".

A hammer is a two piece machine. Two parts, a cast head and a shaft.

Do hammers fail? Sure they do. Aircrafts have millions of parts yet they are the most reliable form of transporation on the planet.

Ridiculous comparison? Sure...but it's equally ridiculous to say that a pushrod valve actuation system is more reliable simply because it has fewer moving parts.

That's because the motions involved, parts used, forces applied and trasferred are completely different! If anything, a pushrod design is more "rube goldberg" as the distance the force actuation must travel is much further and less robust...lending to the NVH and high RPM issues pushrod engines have.

Overhead cam engines have more moving parts, but the actual force transfer is more robust. The lever arms and linkages are shorter and more stout. The inertia of the actuation parts is less. The factor of safety can be higher. This is why OHC engines can reach 20k RPM, and pushrod engines cannot.

What does that mean? Well, if you are looking at TWO SEPARATE designs BOTH for actuating the valves on the LS7 via pushrods...then, yes. Your statement applies. The simple design may well be the better option. There are good pushrod designs and bad pushrod designs. There are good OHC designs and bad OHC designs. The only real engineering analysis you can make is to analyze each individual system and determine what part has the lowest factor of safety. Also, an complete FMEA analysis would help too.

However, you cannot compare to completely different processes and proclaim that fewer parts is more reliable as the forces, stresses, and factors of safety are completely different between the two methods.

pDz

V:

i appreciate the BMW V10 street motor as an engineering exercise --but if it was my money, i'd still buy a car with the new MB 6.3 litre engine. same peak HP numbers, but far superior torque numbers.

yeah, you need more displacement in the DOHC design to achieve the torque, but to me, that's worth it.

Blocktrdr

IMO this is a worhtless argument. The Diesel in the Audi R10 should be engine of the year. After that any of the new V8's in this year's F1 cars. Entirely new motors put in an extremely harsh environment and they are showing remarkable longevity. The Carrera GT motor isnt new, but the Bugatti Veyron Motor is. I would rate that above as well. What about Saleen releasing the new S7's twin turbo motor with 700 and some odd HP? There are several new motors better than these two.

ghoffman

"carrera GT motor:
452lbs 605HP
discuss...
Cost must always be an independent variable in the design considerations. I will guarantee you only one thing 100%; given no cost restraints whatsoever every single part on any car could be improved. Does anyone know what a BMW or Carrera GT crate engine costs? It would be surprising if you could get the Carrera GT motor for less than $150K. I can get a complete LS-7 for $13k. Does anyone think that given the delta cost the LS7 would not be improved?

EuG

I agree.

Got me very curious, so I read up on this motor a bit.

I must admit – it sounds incredible and Porsche must be given mad props for it!
However, one can’t ignore that it’s totally maxed out effort, cost not a factor engine.

LS7 is not only not maxed out, but detuned from factory as well.
It’s a confirmed fact that LS7 can make ~550bHP w/o any changes to the engine itself (just more aggressive tune and less restrictive air intake)

I have absolutely no doubt that a much more aggressive (yet still emission compliant) LS7 will make 600bHP+ w/o even breaking a sweat.

Once again, I’m VERY impressed with this Carrera GT engine and technology that went into it and not trying to take away anything from it , just discussing as you asked

Verrückt

I'm going to go ahead and call you out on that statement.

Try this.

Floor your car in first gear at 1000 RPM.

Now floor your car in 6th gear at 1000 RPM.

Notice the difference? In both cases, your engine is making the same horsepower and torque. The ONLY DIFFERENCE is the actual torque the wheels apply to the road through gearing. At those speeds the aerodynamics can be ignored.

I think you'll find a slight difference to say the least.



That's the effect of gearing on acceleration.

Verrückt

There is more than one tuner out there who will install twin turbos on the Carrera GT getting you 1000 hp+. It's not that big of a deal because obviously the same type of kits exist for the Corvette.

I have no other information on what types of modifications are required.

One link

Gemballa has one in development, but no one has seen a real car yet.

EuG

The problem with your argument is that you’re thinking “instantaneous”

The difference between accelerating from 1000rpm in 1st gear vs. in 6th gear is that your RPMs (and hence HP) will be climbing much more rapidly in 1st than in 6th.
Therefore the total HP during that run will be much greater in 1st gear and therefore car will accelerate much faster in 1st gear.

You can twist this inside and out, but there’s no getting away from physics.
HP is the only thing that matters for acceleration because it’s the rate of how fast work is being performed - by definition.

EuG

I understand.
I didn’t mean to say that there’s no way to add HP to Carrera GT.
You can turbo or Nitrous any motor – that’s granted

I was speaking strictly NA, since we’re discussing the motor itself.
I think forced induction systems should be left out of such discussions, because it really bears on a totally different subject.

Guibo

But an aircraft requires considerably more maintenance than a car, right? Or a hammer, for that matter. I can jump in my car, go to the corner store, or go on a 50-mile trip, with no worries whatsoever. Would you trust an aircraft trip of any length in which you knew absolutely no checks were done before flight?
Then consider the millions (billions?) of hammers used everday vs the # of aircraft. All used without "pre-use inspection" . Surely, you're not implying that hammers need to be more complicated? The fact that they are this simple should tell you something.

And regarding those fuel economy numbers, the EPA results may be flawed, but that doesn't mean the Euro tests are the final word either. If you look at the Euro test, vs what German mags like Sport Auto and AMS have gotten with both cars, you'd see the M5's official Euro ratings are likewise optimistic.
Alternatively, you could look at real-world driving results by owners and other mags. From an M5 forum fuel economy thread with about 20 respondents, the average of mixed driving was about 12.0 mpg. The average of highway driving was 15.6 mpg. FWIW, R&T and C&D got 10.9 and 11.0 mpg in mixed driving.
From the recent Z06 forum economy threads, with about 14 respondents, the average mixed driving was 15.4 mpg. The average of highway driving was 26.3 mpg. R&T and C&D got 17.0 and 18.0 in mixed driving for the Z06.
By the Euro ratings, the M5 gets only .2 L/100 km worse than the Z06 in highway driving, or 23.0 vs 23.5 mpg. That's sort of a joke, considering those real-world driving experiences (and yes, many of those Z06 drivers were doing 70+ mph). And as an example, AMS got 20.5 for the M5. That's much less than their figure for the Z06: 26.0. (What's the Z06's EPA highway figure again?)

blandcastle

Excellent point Major!

nick@carter.in

Meir David

hi friend

Dont know exact weight,

but I'd not think it is any more than the 346. Still al. small block, crank is forged, rods are TI, heads are AL....