Is Infiniti Dumbing Down the HP Rating on the 'Vert?

[TerribleONE453]

yea.. ^ honestly hes a respected guy on the forums so dont be so quick to bash people. i used to love being on here and now its played out cause of all the trash talk

[Seer]

probably just a more restrictive exhaust.

[JohnEnglish]

Originally Posted by Seer

probably just a more restrictive exhaust.

Yeah, they probably did this to make it a bit quieter for top down crusing.

[G37Sam]

come on people newton's second law: F=ma lol

[JohnEnglish]

Originally Posted by G37Sam

come on people newton's second law: F=ma lol

[g37sick]

Originally Posted by jinu123nyc

that is by far the dumbest quote in this forum

no offense - and i'm sorry if you got angry

he meant it seems like the hp is less cuz extra weight makes ur car sloooooowwwwwwer

[boostard]

Just a bit of FYI to the OP... there will ALWAYS be a different HP/Tq (in terms WHP/WTq, be it corrected or not) rating between automatic and manual transmissions, even on cars with the exact same engine. There is more parasitic power loss when transmitted through an ATX then an MT, each time and every time. Same goes for drive wheels. A RWD car will have a greater engine to wheel power loss then a FWD car, and an AWD car will have more loss then either of the two.

Of course, most manufacturers will only state BHP, which is rated at the flywheel and not the drive wheels, so that figure would remain the same no matter what transmission or drive wheel configuration is used.

[KAHBOOM]

Originally Posted by boostard

Just a bit of FYI to the OP... there will ALWAYS be a different HP/Tq (in terms WHP/WTq, be it corrected or not) rating between automatic and manual transmissions, even on cars with the exact same engine. There is more parasitic power loss when transmitted through an ATX then an MT, each time and every time. Same goes for drive wheels. A RWD car will have a greater engine to wheel power loss then a FWD car, and an AWD car will have more loss then either of the two.

Of course, most manufacturers will only state BHP, which is rated at the flywheel and not the drive wheels, so that figure would remain the same no matter what transmission or drive wheel configuration is used.

If you do a little research on our trannys there is actually very little difference between the AT and MT on these cars. Most have dyno's within 2 or 3 hp of eachother under the same conditions.

[Mike]

Originally Posted by boostard

Just a bit of FYI to the OP... there will ALWAYS be a different HP/Tq (in terms WHP/WTq, be it corrected or not) rating between automatic and manual transmissions, even on cars with the exact same engine. There is more parasitic power loss when transmitted through an ATX then an MT, each time and every time. Same goes for drive wheels. A RWD car will have a greater engine to wheel power loss then a FWD car, and an AWD car will have more loss then either of the two.

Of course, most manufacturers will only state BHP, which is rated at the flywheel and not the drive wheels, so that figure would remain the same no matter what transmission or drive wheel configuration is used.

there will ALWAYS be a difference in hp/tq ratings among the same engine make/model with the same type of tranny as well.

This is a moot point

[boostard]

Originally Posted by Mike

This is a moot point

Not really, given that I was referring to this quote from the OP...

Infiniti's had a history of fiddling with the hp ratings on its V6 engines, like 260 in the '03-'04 sedan vs. 280 in the coupe, and then equalizing both in '05 but giving the MT versions 298 (or 293hp SAE revised).

Originally Posted by KAHBOOM

If you do a little research on our trannys there is actually very little difference between the AT and MT on these cars. Most have dyno's within 2 or 3 hp of eachother under the same conditions.

And you do realize that unless the dynos are done on the same machine under the exact same conditions (e.g. back to back), you cant really compare dyno charts given the large differences in numbers produced by variables such as type of dyno, specific dyno, software used, altitude, temp, humidity, (not even counting the many variables between different cars even of the same make and model), etc... etc... etc... right?

[Mike]

Originally Posted by boostard

And you do realize that unless the dynos are done on the same machine under the exact same conditions (e.g. back to back), you cant really compare dyno charts given the large differences in numbers produced by variables such as type of dyno, specific dyno, software used, altitude, temp, humidity, (not even counting the many variables between different cars even of the same make and model), etc... etc... etc... right?

Incorrect

As long as the SAME dyno is used and the calibration is unchanged, correction will factor for atmospheric pressure, temperature, and humidity. Altitude is not a concern.

Given your statement, no two dyno pulls can ever be compared cuz conditions change in real time, and will never be identical twice.

Anyways, the engine DOES output different power on different models.

[boostard]

Originally Posted by Mike

Incorrect

As long as the SAME dyno is used and the calibration is unchanged, correction will factor for atmospheric pressure, temperature, and humidity. Altitude is not a concern.

Given your statement, no two dyno pulls can ever be compared cuz conditions change in real time, and will never be identical twice.

Anyways, the engine DOES output different power on different models.

That's a load of crap, seeing as how I operated a dynapack for 4 years of my life. I can tell you with no uncertain terms that even the same car on the same machine and with the same technician, will pull different numbers if done on varying days or even times of day (keep in mind dynapacks are more consistent then most due to it measuring at the hub and not wheel). Also SAE correction (or whichever other method used) only uses a general set of numbers to compensate for altitude. The actual numbers can and will be off by enough to throw this specific case out the window (MT vs AT on the same make/model/trim vehicle).

BTW, who said anything to the contrary about different model cars not making the same power? Not I. I only stated about the differences between transmission types.

...and when you are trying to compare the difference of ~5-10 HP, then YES, it makes it very hard to compare dynos which are done at the same place on the same day let alone at on different days and at different places (and on different types of dynos as the case may be).

In any case, Id like to see these dyno charts which were mentioned showing "2 to 3 HP" differences between MT and ATX models. I would also be interested to see when, or better yet WHERE they were performed and on which type of machine. Without those last two variables accounted for, your "proof" isn't worth much.

[KAHBOOM]

Originally Posted by boostard

Not really, given that I was referring to this quote from the OP...





And you do realize that unless the dynos are done on the same machine under the exact same conditions (e.g. back to back), you cant really compare dyno charts given the large differences in numbers produced by variables such as type of dyno, specific dyno, software used, altitude, temp, humidity, (not even counting the many variables between different cars even of the same make and model), etc... etc... etc... right?

You did read my post right? They were done on the same day "under the same conditions" on the same dyno back to back. This was demonstrated on multiple occassions.

[KAHBOOM]

Originally Posted by boostard

That's a load of crap, seeing as how I operated a dynapack for 4 years of my life. I can tell you with no uncertain terms that even the same car on the same machine and with the same technician, will pull different numbers if done on varying days or even times of day (keep in mind dynapacks are more consistent then most due to it measuring at the hub and not wheel). Also SAE correction (or whichever other method used) only uses a general set of numbers to compensate for altitude. The actual numbers can and will be off by enough to throw this specific case out the window (MT vs AT on the same make/model/trim vehicle).

BTW, who said anything to the contrary about different model cars not making the same power? Not I. I only stated about the differences between transmission types.

...and when you are trying to compare the difference of ~5-10 HP, then YES, it makes it very hard to compare dynos which are done at the same place on the same day let alone at on different days and at different places (and on different types of dynos as the case may be).

In any case, Id like to see these dyno charts which were mentioned showing "2 to 3 HP" differences between MT and ATX models. I would also be interested to see when, or better yet WHERE they were performed and on which type of machine. Without those last two variables accounted for, your "proof" isn't worth much.

Do a search they are out there. Also check out my350Z and driver in the Sedan section. Vendors have likewise made similar observations. I have searched and posted these a couple of times in the past. I'll let someone else do the research this time


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edit.. so I lied.. Here is the link to the G35 dynos. Particularly look at the 5AT HR dyno (second from bottom) and the 6MT
HR dyno (at the bottom). They are within 2 to 5 HP of eachother
http://g35driver.com/forums/1684290-post1.html

There are more out there with the G37 dyno'd that Gamedog and another member did as well as others.

[Mike]

Originally Posted by boostard

That's a load of crap, seeing as how I operated a dynapack for 4 years of my life. I can tell you with no uncertain terms that even the same car on the same machine and with the same technician, will pull different numbers if done on varying days or even times of day (keep in mind dynapacks are more consistent then most due to it measuring at the hub and not wheel). Also SAE correction (or whichever other method used) only uses a general set of numbers to compensate for altitude. The actual numbers can and will be off by enough to throw this specific case out the window (MT vs AT on the same make/model/trim vehicle).

As you said, using a Dynapack eliminates the variable of having different rotating masses and potential wheel slip.

So, lets identify the variables.

1. variation per pull. Each pull will always vary, same car, pulls as close to each other as possible, no changes to the car itself.

2. Air Temp/Pressure

3. Air Humidity


#1 can't be avoided. We all know that.

2. Temp/Pressure can be corrected for. Perfectly. pV = nRT. If IAT is higher, then output will be lower. Why? Because there is less actual air going into the engine. Cooler air = denser air, given the same pressure. Exactly why Intercoolers/Aftercoolers/Heat exchangers are used. They lower IAT, which allows for less boost (thus less pressure) to yield the same or more horsepower. A cool, clear day will always yield more power than a hot rainy day, which leads us to our third point.

3. Humidity can also be corrected for. 100% Humidity will yield less power than 0% humidity. Humidity is water in vapor form. Water vapor in the air displaces oxygen molecules (among others), so that less is available to combust, resulting in less output.


Have I missed some variable that can lead to differing dynos?