Opinions?

I think the times will be exactly the same or even a little bit slower.
When adding two gears to the car, they will have to shorten the gear ratios to squeeze in an extra two. While this will help fuel economy, the G37 will most likely not be able to get to 100mph in 3rd, but instead will require an additional shift to 4th in the 1/4 mile.
Just my opinion

 

The extra shift into 4th for the 6MT drivers is no big deal. The question is *where* in fourth will the car be when shifting from 3rd?

 

With more power and deeper gearing, the 7AT G37 sedan will be significantly (.3 seconds at least) quicker than the current G35 5AT. Look at the IS350 with it's 6AT. Those cars have really deep gearing, make about 260whp, weigh 3,600lbs, and tend to see 13.5-13.6@103mph+. The new G37 will weigh 3,600lbs, make 280whp, and have similiar gearing to the IS350. I don't why the new G37 sedan couldn't do 13.5s quite easily with some gracing 13.4s or even better.

 

G37's don't even make 280whp...and it was announced our cars are tuned to 328hp...so how are you getting these numbers? 260whp at best

the easiest way to get a car's whp is to divide the bhp by 1.28 and it'll be pretty close....show me a dyno of a stock g37 doing 280

 

^^^you can't generalize a car's drivetrain efficiency with a single equation. Each will be different.

 

Well adding 2 gears does not mean all the gears are going to be useful. If the current 6mt had the same gearing as the pre 07 6MT gearing it would be much quicker. Now going with 7speed might shorten the gears enough to be very similar to pre 07 6mt gearing.

The current 6mts are geared very similarly as the pre 07 autos. 1st 35-40 mph 2nd close to 60 and 3rd gear goes all the way to 100mph which is just too long for a V6 motor. Hopefuly 7at ratios will allow a extra gear from 60-100mph and the car will become much quicker.

The IS350 has identical acceleration as the current G35s. IS350 can do sub 2.0 60ft on stock tires for some reason that is why u are seeing those incredible 1/4 mile times for that car. Do a 10mph - 100mph run with the current G35 and u will be surprised that after 3rd gear (@~90mph) IS350 starts falling back.

The bottom line is that if the car is geared more agressively from 60-100 then yes it should become much quicker than the current one.

 

My 06 5AT doesn't go to 100 in 3rd gear?! It's hitting redline in the 80ish mph range.

 

of course every car will be a different output in whp, but find me ONE stock G37 that supposedly has higher output than the G37 sedan that has 280whp, that's my argument...

 

My wife's car dyno'd 267whp on a dynojet, bone stock, with about 1k miles on it. It's an 07 G35 sedan 6MT. The assumed drivetrain loss for the 6MT on the first gen car is about 17%, so that puts her car making ~321hp at the crank. A bit more than Nissan's stated 306hp.

To put that in context, my car dyno'd 241.9hp bone stock. Using the same 17% drivetrain loss figure, that put my car making 291hp at the crank stock. In 2005, Infiniti rated the revup at 298hp, but revised that number to 293 in 06/07. So as you can see, that 17% figure is pretty close, at least for the dynojets I've used. After all my mods, I dyno'd 266hp on the same day my wife dyno'd 267hp(same dyno).

Now that we've established what the current VQHR does, we can extrapolate. Reference a couple of posts of the 3.7 liter over on my350z: http://my350z.com/forum/engine-drive...line-dyno.html
http://my350z.com/forum/vq35hr/33089...-same-day.html

The first link shows a bone stock g37 dyno on sharif's dyno. On that same dyno, I put down 246hp - 3 less than the g37 does stock.

And the second link shows that the 3.7 is making hardly any more power than the 3.5.

So basically, I figure that the g37 sedan will be putting down about 270 to 280(dynojet), depending on the day and dyno. Some optimistic dynos might see 285 to 290.

Regardless, the g37 sedan should see a decent bump in et's and traps from the hp alone, but not as much as one would expect from the manufacturer's rated HP.

 

There's always the first published dynos, available from Motortrend:

http://www.automobilemag.com/reviews...rts/index.html

 

that is impossible with stock 3.3 final drive.

 

From what I understand, it seems like dynojet rates hp higher than any other dyno...because GTM's dyno rated terry's G35 sedan at 259.1whp and Sharif's dyno rated that G37 at 249whp.....

 

I think we are talking about two different things here. I was arguing your divide by 1.28 factor. You said this in a general tone meaning you could do this with any car on the street. That was my argument.

 

No, what I meant by that statement is that YOU WILL COME CLOSE to the rated whp if you do it by that method. I think it is common sense that this method won't give you the exact whp output...

 

I'm sorry, but I don't follow you at all. That's probably my fault because I wasn't clear in my post.

Allow me to walk you through some of my dyno history. My car is an 05 6MT. In 05 it was rated at 298hp, then that number was revised to 293hp. When my car dynod bone stock on a local dynojet, it put down 242hp(rounded up).

So what was my car making at the crank at the time? I use the 17% figure for drivetrain loss. You probably wonder where I got that figure. I got it from Doug Stewart; the guy behind Crawford(crawford plenum, headers, cats, etc).

When you plug in that 17% figure, based on that dynojet on that day, then my car made about 291hp at the crank. That figure is awfully close to Nissan's revised crank numbers.

Now, after all my mods and tune, my car last dyno'd at 266hp. Because I trust that 17% figure, that puts me making about 320hp - almost a 30hp gain at the crank.

On the same day and dyno that I put down 266, my wife's VQ35HR 6MT put down 267hp. I don't think the 6MT drivetrain components changed significantly enough between 06 and 07 to dramatically affect the drivetrain loss, so I will continue to use the 17% factor. So at 266rwhp, my wife's car is making *roughly* 321hp at the crank. This time it seems that Nissan's numbers are a bit off.

I'm not quoting best case numbers, and although it's not a good practice to compare the numbers from different dynos, I can do that in the case of Sharif's dyno because my car has been on his dyno. At his place, my car put down 246hp to the wheels. That's in Atlanta. The very same day, back in Birmingham, my car put down 265hp on a dynojet. Granted, that's one less hp than my ultimate best of 266, but that's completely within variance.

So by following this progression of events, one can make a reasonably assumption of what my wife's car would make on Sharif's dyno. Her car would put down 246 or 247hp, depending on rounding. The g37 in that first link put down 249hp in 5th gear, or roughly 2hp more than my wife's car's adjusted numbers.

Some one please tell me where I'm going wrong?