aco

cough...Audi R10...cough

lobuxracer

iTrader: (2)

Those are to prevent oil from pooling in the head under high g loads. Its a common problem along with oil in the pan moving away from the pickup.

05RollaXRS

^^^

Werd.

Look at Porsche 911 GT3 997. It has a small 3.6 Liter boxer flat 6 engine making 415 HP@7800 rpm and a 8400 rpm redline with 300 ft-lbs of torque. That is 115 HP/Liter.

It tears a 0-60 in only 3.8 seconds and 1/4 mile in 12.1 secs. It sounds like a genuine racing car. That is faster than a Corvette base coupe with 400 HP and 400 ft-lbs of torque.

Secret is in short aggressive gearing to match the power under the curve (amplifying the torque to the wheels in a phenomenon called "torque multiplcation"), a flat power under the curve from the low end right up to 8400 rpm (gets 80% of it's torque below 3000 rpm).

lobuxracer

iTrader: (2)

That's why I say someday we may be racing diesels...still, if you look at the competition in the class they're in and the type of racing they're doing it says a lot for why a diesel is a good choice for Audi. Le Mans racing isn't nearly as competitive as open wheel racing, and so far, no one has attempted to build a diesel for open wheel (F1/F2/F3, etc) where they compete against gasoline powered engines. Again, that day may come, and it may be sooner than we think, but so far, no one has done it.

FWIW, diesels have ruled in off-shore powerboating for quite awhile. It's a perfect application for diesel technology.

TRDFantasy

Indeed it is. I'm just wondering and hoping that there will be additional mods to the engine's internals made.

RocketGuy3

iTrader: (1)

Thanks, that clears a lot of things up...

But I think that means that at least one of the things I was getting at is true: assuming peak power remains constant, there isn't likely to be any real advantage in a higher-revving engine than a lower-revving one, right?

05RollaXRS

It is a typical big displacement muscle car vs small displacement high powered and highly engineeried car debate.


The advantages are:

- Can use much smaller displacement and put light weight forged pistons and internals in order to make the car rev freely up to high rpms. A big displacement engine with a lot of low end torque must have strong and heavy internals to handle the torque down low, which in turn means a much heavier engine.

- Lighter engine means better front to back balance and less understeer.

- With the engine free revving and proper tuning using engine management technology, peak torque can be spread across a huge rev band up to redline, which makes the low end torque usable in every day driving and make sure it never dies off at high rpm.

- What is the point of having tons of torque in the first 2000 rpm when 90% of the drivers cannot control it and can result the car to spin out and waste it?

- Can utilize short gearing (and final drive) to match the powerband of the car since a massive rpm band makes up for the shortness of each gear and amplify the torque to the wheels since wheel torque is a product of crank torque and total transmission ratio (final drive, gear ratios, axle ratios). So if a high revving engine can make a lot of HP at high rpm and maintain a max. flat torque curve across a wide rpm band, it can make up for not-so-impressive peak crank torque through luxury of aggressive gearing.

- Power is a lot more controllable in corners and full throttle with less risk of losing control and spining out, which means faster cornering speeds. A lot of power is wasted if the chasis cannot handle the low end torque since the rear end can slide out due to heavy oversteer causing the car to spin out. Mercedes AMG cars have this problem where their chasis are not able to handle the massive low end torque.

- Sounds a lot more exciting because of the race car like sound at high rpm.

LexFather

Porsche knows their shiat

CK6Speed

iTrader: (1)

Personally, I love high reving high strung engines. I just the sound of it. Plus, I used to have a blast shifting at 8000 RPM. That was the highest reving car I personally had. I don't ride bikes so that doesn't count.

lobuxracer

iTrader: (2)

My 1985 500 Interceptor redlined at 12,500 and hit the rev limiter at 13,500. Pretty cool for a little V-4.

lobuxracer

iTrader: (2)

This is not possible. You give up low end power for high end power in small engines. If you want advantageous hp on top, you will undoubtedly sacrifice hp at low rpm. It may not be all bad, but it's not possible to have your cake and eat it too for a lot of reasons that are basic to engine design.

05RollaXRS

Yes, you are right. You do sacrifice low end.

What I meant to say was that it is not completely peaky and temperamental. You do compromise on the peak torque that could be achieved at a much lower rpm with a long stroked and low revivng engine, but with modern engine management technology, most of the high revving engines can achieve 75 - 80% or more of their peak torque within the first 3000 rpm, which atleast gives decent daily drivability.

RocketGuy3

iTrader: (1)

Similarly, couldn't you use a taller gear in the higher-torque, lower-revving engine to get the same effect? (Again, keep in mind that this engine would have the same peak power output.)

And I don't really see why a lower-revving engine would be any less able to have a fairly flat torque curve.

Exodusfrit

Don't get me wrong here I love the IS-F. When I was looking for a new car a few years ago I drove the Lexus IS-250. The salesman asked me what I thought. I told him the car felt sedated and slow. He then said ok try our "rocket ship" the IS-350. The car was one of the most comfortable cars I have been in but it still felt very unexciting to drive. I told him his rocket ship was slow and he had enough of me. At that time the IS-F was not yet available.

So to replace my supra turbo I bought an E46 M3. I recently raced an IS-F and easily overtook it and had 4 car lengths between us before slowing down for the up coming light. Someone on this forum said that rpm doesn't equate to horsepower but I am confident that my 330 hp M3 outperformed the IS-F because it's redline is close to 8000 rpm. Which is way higher than the Lexus. The M3 does not die out at high rpm either. Though the 8 speed in the Lexus is good for gas mileage - the fact is the more often you have to shift the longer it's going to take to accelerate. It's more of a gimmick where as the M3 is engineered for performance all around which makes the 6 speed more practical for performance.

In my opinion the M3 is the better car. The IS-F sure is pretty though.

ISFJames

iTrader: (4)

You sound like a typical BMW driver. lol yes, your bmw is gods gifts to dbag bmw drivers everywhere. You probably raced a 350. Even with the 350, you're not going to get 4 lengths.