SteVTEC

Haven't done one of these in awhile.

This is stemming from discussion in this thread 2002 Max 255HP, 2004 265HP WHY?? which you can checkout and read through if you want, but I figured I would post this seperately also.


Okay here it is. First off....

IGNORE THE HUMP AT THE TOP OF THE DYNO CURVES

That's Excel extrapolation error trying to "curve fit" to the next data point which is zero where it cuts off and I haven't bothered to try and figure out how to turn that crap off yet. The chart would make you believe that a G35 is hitting 235 rwhp, but this stock dyno I found for one was at 231 rwhp. The Maxima was at 205 fwhp.

So...........




Aside from the little hump at 4800 rpm on the G35, the G engine really doesn't have much more than 5 wtq more than the 02-03 Maxima, yet it's a significantly more powerful overall engine. Why? Area under the curve. The G has a much flatter overall torque curve, especially in the top-end above 5000 rpm. That's what results in all of the extra peak horsepower since HP = (TQ x RPM) / 5252. Once the VQ35DE version in the G35 is wound up to 5000 rpm it'll begin steadily walking the older 02/03 version that's in the Maxima and over a 1/4 mile, that's what makes the G a few tenths and a few MPH faster than an 02/03 Maxima.

Another way to look at it is like this - normalizing the torque curves for each car to a percentage of their peak value. This lets you compare the "powerband" of a Civic to say a Dodge Viper if you wanted to.




So the G and Max are more or less equal with maybe a slight advantage to the Maxima in the low/medium revs as far as powerband goes, but the version in the G just blows the Max version away at higher revs, and you can see that very easily here. The G35 maintains 90% of peak torque over a wider range than the 02/03 Maxima does.

Now the next thing I need to do is go find that Technosquare ECU dyno for the 02 Maxima and plot it against the G35 one more time. I know the ECU fixes the top-end a lot. Hmmmm....

nismos14

iTrader: (56)

sweet graet analysis and dyno perspectives

mAdD MAX

I thought this was common knowledge that the G35 has different powerband than the 2002 Maxima.

The VQ35DE in the G35/Z/04 Maxima/etc.. is of a different generation than the 3.5L in the 02 Maxima/Pathfinder.

They increased the top-end and smoothed out the torque curve with their changes in intake and ecu.

SteVTEC

There's always some newbies who are just learning.

Plus there was some confusion in the other thread on how the newer gen VQ35DE engines could have so much more top-end without much if any additional peak torque, so this dyno overlay illustrates that.

mAdD MAX

Good point.

Do you have that pdf from SAE that outlined the technical aspects of the 3.5L VQ motor? It outlined the changes made between the generations. It was posted on the Org a while back..but seems to have dissappaered.

This is the title of the paper: Second Generation of High-Response V6 Engine Series (3.0 and 3.5 Liters) which can be found from the SAE website.
They had some other interesting papers on Nissan's High Peformance V8...but sadly you must pay $12 to view them.

SteVTEC

I have a whole bunch of SAE documents on all sorts of different engines now, including that one.

DamNScuM

iTrader: (1)

We need more posts like this. Love your work SteVTEC, I always enjoy your stuff.

happyricefob

iTrader: (7)

what do u mean?

hakk97se

How much of this could be attributed to the characteristics of a FWD drivetrain vs RWD?? I would have thought that they gave a "bump" to the G35's power due to some additional RWD drivetrain loss. And would it matter if the G35 was the version with the semi-limited slip differential? (speaking in terms of loss or power conversion, not traction).

But yeah, my mom owns an 03 maxima and i've test driven a few G's.. the G is definitely smoother feeling, but like I said, I always attributed the different "feeling" to the RWD aspect. However, I realize that will have less impact on a dyno..

F23A4

nice job Steve.