Per some other posts referring to a _Motor Trend_ article, the new G engine is rated 306 hp.

It sounds like the Marketeers trumped the engineers and either forced an underrating or a detuning of the "significantly revised" engine in the '07 G. Given the 5.4 second 0-60, it seems some detuning has occurred.

Per Infiniti's New York auto show press release, the engine has 80% of its parts redesigned, rev limit increased from 6600 to 7500, and, more significantly, goes with variable valve timing on both intake and exhaust.

IMHO, that engine should be capable of at least 100 hp/liter. By comparison, the 3.5 liter in the Honda RL is single cam VTEC and generates around 290. BMW's M engine gets 330 hp out of 3.2 liters. Ol' Carlos Ghohn would be rolling some heads in the engineering department if all that investment only yielded 8 peak hp.

I thought maybe the engineers might prefer a flatter torque curve and not take full advantage of the better breathing at higher RPM; and then I see the talk about "swelling power with higher rpm", which seems to be marketspeak for a nonflat torque curve.

Another thing that comes to mind is maybe the 306 hp can be had using 87 octane gas. However, the press release also talks about increased compression ratio which might suggest otherwise. I suppose they could still program ignition timing to heavily retard the timing under load which would be a good reason for cutting 50 or so hp off the top end.

When I first started salivating over the G 6-speed in summer '03, it could be had with around 260 hp burning 87 octane... 3 years later, 298 on premium.

Given the delay in releasing hp figures from the NY show, I suspect there was a lot of hand wringing going on over how much to trump the competition in hp (1 more than an IS350, sounds like the dominant marketeer watched "This is Spinal Tap" the night before). I haven't looked at the Infiniti M to know its specs - the marketers wouldn't want to threaten their own next higher up model, either. I predict the G35 gets "350+" hp after the M finds closer to 400 hp...because those average consumers are too ignorant to shop on power delivery vs. peak numbers - ie, if the G and M both had 350 peak hp, average Joe would fail to understand the M has a better bottom end.

Oh, I suppose we can't forget the Skyline GTR, future 350Z, and G35 coupe which can't possibly be forced to "settle" for the meager hp of a sister sedan. That was the marketing model Infiniti followed in '02/03 - coupes debut with stronger specs, sedan matches later (especially if the coupes are to be priced higher). BMW is also doing that with its 3 series. That sure is frustrating to us folks in the baby seat world.

Any ideas on how Infiniti might detune the engine? With throttle by wire, they could simply program the computer not to open the throttle all the way. I wonder what costs them more - software revisions or completely different air induction and fuel delivery parts... Aftermarketers, reprogrammed chip or revised throttle linkage?

Personally, I was seriously considering an '07 G assuming they were going to increase the power more significantly. Now, I'm thinking I'll wait. I always feel duped and manipulated when I know future power increases are released based upon marketing plans rather than the real speed of R&D.

Comments?

 

The other numbers went down under the new system (pre-07 engines). If they kept the same system the 07' would have been more like 315+.

 

it is not only about the peak numbers my friend, it is more about numbers under curve..and the tuning potentials

 

The coupe was rated higher from the get go in order to help justify its higher MSRP. The sedan was blesed with the same power of the coupe from day one. I dont think you should feel duped at all. And there is no question that the new HR engine produces a good amount more power than the VQ it replaces. 0-60 in 5.4 and better economy? The numbers speak for themselfs. I wouldnt be surprised if those 0-60 times started to fall to the 5.1 range as the car breaks in and weather conditions improve. Its much more than a 8 hp difference.

 

the torque curve is supposed to be broad and the higher redline allows for slightly shorter gearing (according to the motor trend article in the other thread), so the power increase is more than it may seem.

I imagine they could have tuned it for a few more peak HP but at the cost of power in other places. They could have also put peak torque at a higher RPM, which would make more peak HP, possibly even beating figures from the 333HP from the M3... but really unpractical since you usually dont drive up to 6000/6500/7000rpm in everyday driving.

 

So will we have some of the last cars with a VQ motor?

 

It does sound disappointing but you are not looking at the facts:

1) This is under the new engine ratings. The current VQ was rated under the old system and would probably drop 20hp under the new, more restrictive rating.

2) Peak hp does not paint the whole picture. It's all about bottom end torque and the amount of power through the revs.

3) The engine is tuned for better gas mileage (10% better I think). So not only is it making more power, it's doing it more efficiently.

4) Getting 100hp per liter is not as easy as you think. The vtec motors have to be revved to 6000 or whatever to get their power. Germans are pretty good at getting power from smaller motors but at a price. You also have to consider reliability and smooth power delivery.

 

Actually, the 05/06 auto 280hp engine only went down 5 horsepower in 07, look at the ratings for the 07 G35 coupe auto. 275HP...

 

What about the rev-up engine? How much did it go down?

 

Found it:

For 2007, the standard VQ 3.5-liter DOHC 24-valve V6 engine produces 275 horsepower and 268 lb-ft of torque, while the G35 Coupe 6MT model generates 293 horsepower and 258 lb-ft of torque.


So even if the new VQ only made 5 more hp under the old numbers it is still 311 with a better torque curve and mpg.