shabbo

definitely...the Infiniti folks have to stick to the business and marketing plan.

as far as maximum rpm I think that 8000 rpm is really pushing it for an engine like this no matter how light the cams and springs maybe, airflow is the bottleneck....

IDEA..maybe Nissan can develop VCEL on the Crankshaft to increase Compression ratio to produce more torque at higher rpm.

12fear

vvel is only on the intake side not the exhaust side. exhaust side is conventional.

SilverRSXJezus

Gotcha.




ITBs anyone? That would quite awesome to hear those on a G...haven't come across one yet.

trebien

Yes and no. Exhaust is variable timed, as well as the intake. But it's the CVTCS.

Sorry, I should have been more clear in my post, and it's worded poorly. Where I said "This is the new "vtec""... I was implying and should have said "This system is the new "vtec"", with "system" including the CVTCS operation... which I was lumping in with the VVEL.

Yes, VVEL only acts on the intake valves. It varies the event and lift of the valve... how long it stays open and how much it opens... controlling airflow at the cylinder and acting kind of like a throttle body.

But both the intake AND exhaust have CVTCS - continuously variable valve timing control.

I believe in the past, the HR had variable intake and exhasut. And before that, the VQ went through 2 iterations, the second adding the 2 mode exhaust timing, as in the 298HP upgrade to the 2005 G35. Before that, it was only intake side.

PearlG37

I disagree. How is it common sense to compare a car that cost ~3x as much? It's not an apples to apples comparison. As SilverRSXJezus pointed out the G37 has to be affordable.

shabbo

yeah but they're folks even willing to compare the GT3 to cars that cost 5x as much!! so why can't we also have some fun !!

We're not comparing cars just engines...imo it's as apples-to-apples as it gets:

1) 6 cyl vs 6 cyl
2) 7500 rpm vs 7500 rpm
3) 12:1 vs 11:1
4) 3.6 liter vs 3.7 liter
5) H vs V
6) 3.01 vs 3.39 stroke
7) VarioCam vs VVEL

etc.

PearlG37

Dude, don't get me wrong, I'm all for the technical discussion, but your missing the point. The engine on the Porsche is a big driver for the cost of the car. If Infiniti dumped a ton more into R&D and different parts for a 3.7L that would compete with a Porsche, the car wouldn't cost the same. The increase in cost means their missing their target buyers.

Second, your number 1 and 2 point could be compared with any car. Above everything else, your comparing an H vs V and stating that is an apples to apples comparison?

Show me a stock NA 3.7L (or very similar) V6 in the $40k price range that gives a higher, flatter torque curve. Then maybe I'll be disappointed too.

shabbo

All engines can be compared for specs and output characteristics and we're not children here that think we have a 50$K engine in a $40K car! come on.

and how many 6 cyl engines do you know with a displacement of 3.7+ that can rev to 7500+ in a flash? perhaps you can mention one and we can do another apples for apples for your sake with respect to 'torque' (to keep true to this thread)

The VQ37 is quite sophisticated and if you don't think so then please point out your logic without trying to say that everyone else talking is out of their minds.

according to your statements even the Nissan GTR cannot be compared to a Porsche GT2 given the $$$ delta....so lets drop that argument at least.

SilverRSXJezus

I mean....loook at it another way.


The E46 M3 with its 3.2 Inline 6 was putting out around 270 ft/lbs of torque, 333 hp.

The new E92 M3 with its 4.0 V8 is putting out around 295 ft/lbs of torque, 415 hp.

It has an increase in displacement of like .8 Liters, but its "peak torque" only increased by around 25 ft/lbs. And there's a lot more upgrades and technology pieces implemented on this engine...but at the end of the day is, which one makes more power? Look at the torque curve, it's just so flat.

KAHBOOM

iTrader: (4)

I'm with PEarl. For the money we paid this engine puts out quite a bit of power. Peak torque is only a smalll fraction on the story ere. It has a broad torque range for an engine this size. If it was maximized like the Porsche yeah that would be icing on the cake but I guarantee you that this would no longer be a $40,000 car.

A lot of people have expressed disappointment in yhis cars torques output. I feel that this car is quite powerful. Maybe not compared to other high end models but this car still blows by 90% of the cars on the road today.

trebien

Actually, the differences are larger, and the 4 liter increased more in torque than it seems. The manufacturer output ratings system changed, and the new SAE ratings for the 4 liter are more stringent compared to the older methods, so you can't really compare the numbers.

SilverRSXJezus

But that's just it. As I already stated in the past post, I will guarantee you that BMW has dumped a lot of new technology and money for R&D on this engine, so of course it should be a bigger difference. Then again, look at the price tag, as it's around 1.5 times the price of your average G.


The SAE ratings have also been applied over to the G35 to G37 models, so in that sense you can't compare them either.


But an even more important question is, why are we debating over manufacturer rated hp/torque numbers? I find that to be an incredible waste of time as most car enthusiasts should know by now that half the time they aren't very reliable in predicting the actual car's power output, case in point made by the SRT-4, being rated at 230 hp when it first came out when most cars around then were dynoing around 240ish Wheel horsepower, or how most BMWs are underrated as is.

So you should compare the peak torque generation of a G35 versus a G37 on a dyno in equal conditions above all else to really deliberate as to how much of a gain in peak torque there is to be had, even though as others and I have said, it is a relatively moot point.

shabbo

[QUOTE=KAHBOOM;2449945]I'm with PEarl. For the money we paid this engine puts out quite a bit of power. Peak torque is only a smalll fraction on the story ere. It has a broad torque range for an engine this size. If it was maximized like the Porsche yeah that would be icing on the cake but I guarantee you that this would no longer be a $40,000 car.


We all agree that $40K is the brick wall.

Also by looking and comparing the VQ37 specs, It's seems like this engine is being held back from it's real potential, llikely because of added costs to chassis etc.

But for a couple of thousand dollars extra, we drivers, can safely add another 20lb.ft to the wheels at mid-high rpm...which gives the engine a significantly higher brake HP rating and torque numbers.

as a result I'm not disappointed about torque with this engine!

gshb

you know, we can compare the 3.7L we get in the US to the 3.7L Infiniti sells in other countries. for instance, in the middle east the output of the engine is 350hp @ 7krpm with peak torque 292 lbs ft @ 5200rpm. the only things i can think of that could be different would be missing cats or maybe a different intake system. a different ecu of course.

even stranger are the specs for asia. engine output is rated 328hp @ 7krpm and 327 lbs ft @ 5200 in taiwan? korea states 333hp @ 7krpm and 327 lbs ft @ 5200. i think this might be a typo (37 kgm compared with 33 kgm in the middle east). multiple sites say this, so how is 327 lbs ft possible?

european infiniti sites state 235kW @ 7000 and 360 Nm @ 5200 rpm, which is 315hp and 266 lbs ft. this makes sense, especially for emissions strict europe.

trebien

First of all, the VQ37 does NOT make more power in the middle east. They just have a different ratings system, as opposed to the strict SAE system we use.

As for asia, who knows. I doubt it makes more, but those T numbers are messed up.

But yes, the VQ37 IS detuned in Europe, for emissions purposes. In Europe, you have to pay tax on the amount of emissions, so this is more important than a few extra HP.