I must admit that this discourse has taught me alot about all this. I agree that a "feeling" could be just that. I just think that there is one part we may be missing that would then explain the "feeling".

That being said, I noticed you said "but i do know that the 15% increase in tq at the top of the rpm band definitely get the kind of performance that you observe in an S2k". Why did you differentiate the "top of the rpm band"? Back to looking at just one gear, what makes 130 lb-ft of torque different at 3,000 rpm than at 8,000 rpm. Or am I looking into you rlanguage too much? Up to this point, all of our calcs have left this exact thing out due to all the above reasons from previous posts. That's the part I'm trying to find.

Perhaps we can quantify the acceleration with a magazine road test:

Motor Trend

"The S2000 numbers came after launching at 8000 rpm (producing little tire spin) and shifting at 8300. On one run, we launched and shifted at 5500; the 0-60 time rose to more than 11 seconds. Herein lies the car's biggest problem: Most people will never drive in the best rpm range (7000 to 8500), shifting too early. Our advice is to treat the S2000 like you hate it and you'll get the most out of it. We did and loved every minute of it."

If anyone has the test data (0-30, 0-40, 0-50, etc.) from a car magazine (pre-2004) or can find one on the net, we can use that to see how the acceleration of the car differs across different rpm in the same gear (we'll avoid any 1st gear comparisions due to the uncertainty of launching on 0-30 times).

 

my thoughts on the answer to the above question may differ from my answers earlier on. but either way you seem to be asking for a mathematical explanation to something subjective... which i feel will be difficult (maybe impossible) to do.

but anyway, what i was saying was that maybe people perceive power and not necessarily just thrust. as a result, how much force people think they're being accelerated by becomes difficult to judge accurately.

for instance, people are accustomed to the feeling of acceleration slowing down as speeds increase. so if its maintained, they may preceive that to mean that the thrust is increasing- which may not be true. but it would be true that power is increasing.

so i differentiate the top of the rpm band because maybe people can feel power as well as thrust.

personally i feel the #s already account for that. your acceleration rate would be much slower if you're not up in the rpms in the s2k. i think the dynos do a good job of reflecting that.

 

I agree, but if we see that the acceleration is ALOT faster at a speed where the car is at 8,000 rpm, versus the acceleration compared to when the car is at 3,000 rpm (same gear), then we can deduce that it is not just a feeling. Your chart would show only a 13% gain in torque and force to the wheels but if the acceleration is much more significant than that, then my point might be clearer.

I agree that up to this point, this is all seeming to be me "feeling" soemthing that may not exist. But I'd like to see the actual performance numbers confirm that before I put it to bed.

 

I don't mean to sound cynical but the E46 M3 put out 333 HP and 262lb's of torque out of a 3.2L I6, over 100hp per liter of displacement? thats damn good engineering and gearing and it's 7 years old!

I love my G coupe and i'm sure the aftermarket possibilities will be great, but in a stock comparison i think BMW already did N/A better than infiniti can in a 7 years old motor. =/

 

not to mention it redlines at around 9,000

 

I would hope so. How much more was the M3 than a G35 or G37? And in reality, even though the numbers are the same, the M3 engine originally had mechanical issues and always got ****-poor gas mileage. I give Infiniti a thumbs up - they were able to push a 7,500 rpm redline with a 3.7 liter engine - which is a great feat at such a bargain-price.

By the way, the M3 redline is 8,000 - not 9,000. Because of the high redline, they were able to use more aggresssive gearing which is what helped make it such a quick car (and the relative light weight). If anything, why not compare the M3 to BMW's own 335? It needed 2 turbos to get the same HP/liter as the 7-year old M3. And the 335 is pushing $50k.

 

W E R D

 

Gas mileage was horrible on an M3 and that motor had tendencies to blow up in some M3's

 

Why are people still mentioning the E46 M3 engine? We've already discussed this in this thread.

 

I hate to get into this, but the "needed two turbo's" thing has always bothered me. They didn't *need* the turbo's, they chose to use them. BMW could have easily put a de-tuned version of the M3 engine in the 335i and called it a day; but they engineer a new engine for almost all of their new cars, and in the case of the 335i they clearly thought an engine with more of it's power down low would suit the car, rather than the high revving M3 engine. So for better or worse, I'd say it was a decision based on achieving their goals for the car, not because they had to use turbos to achieve power from an inline 6.

On a side note, given the fact that BMW has a penchant for delivering pretty decent engines, one can probably assume should they have developed a V, they probably could have delivered a 3.3-3.7L engine with over 300hp...

Sorry, not trying to argue, and re: this thread it has definitely been a good one... just wanted to add that since I've seen the "needed turbos" thing before, and I really don't think that was the case.

 

The only reason the 2 turbos was mentioned was that because someone wrote:

"don't mean to sound cynical but the E46 M3 put out 333 HP and 262lb's of torque out of a 3.2L I6, over 100hp per liter of displacement? thats damn good engineering and gearing and it's 7 years old!"

and

"but in a stock comparison i think BMW already did N/A better than infiniti can in a 7 years old motor. =/"

So, I was pointing out how ridiculous the statement is. Why point out that BMW was putting out over 100 HP per liter 7 years ago? What does that have to do with anything? The M3 is BMW's performance division - and their prices are almost double that of the G. So, I was pointing out that the same comparison can be made with BMW's own cars (no need to bring Infiniti into the debate). BMW's own 335 can only muster "100 hp/liter" and that's with 2 turbos. So, the same company that makes the 7-year old motor with 100 hp/liter now can only muster 100 hp/liter 7-years later! We all know they could put out more if they wanted just like Infiniti could if they wanted. The statement was just silly.