05 vs 08 G35

[Headnsouth]

I've got an 05 sedan witch I absolutely love to drive. Plenty of power at least I was happy until I drove my buddies 08.
His car blows me away. From the info I got the 05 has 298 hp 260 torgue while the 08 has 306 HP 268 torgue.

Why is his G so much faster? Both have 80K miles. Never had a problem besides replacing a cam pos sensor a week ago. But now I'm thinking I have issues.
I can't imagine 7 HP makes that much of a difference. Both are factory stock AFAIK.

I'd appreciate any feedback.

[joe603]

Different HP ratings between those years...most likely you don't have an issue.

[Headnsouth]

Different HP ratings between those years...most likely you don't have an issue.

I don't understand. Are the documented HP's different than the HP ratings?

[joe603]

There was a change in how HP was measured...basically, the 2008 has the VQ35HR engine which is more powerful than the VQ35 (2003-2004)

http://www.caranddriver.com/columns/lar ... ion-column

Here is some other info I found...

SAE new horsepower rating system
This has been discussed many times by many people already, but I want to clear up all the issues with this new standard and concerns with the power “decline” of your automobiles.
I worked as a mechanic for some time and currently studying to become a mechanical engineer.
Many people think that horsepower is horsepower, and in a way it is. It’s the measurement of power, which we took more conveniently to measure the potency of the gasoline engines in automobiles instead of Watts. There are different measurements of horsepower. There is an American horsepower (derived by using English units, such as Pound (lb), Feet (ft) and Slugs) and there is metric horsepower (derived by using metric units of the SI system: Newtons (N), meters (m) and kilograms (kg). One metric horsepower PS (PferdeStärke in German) equals to 0.9862 of American horses (hp) or 1 hp equals to 1.0139 PS.

There are different organizations that standardize the horsepower measurements:
DIN (Deuchland Istitute) – German Institute of standards
ECE – European Commission of Economy of EU
ISO – International Standard Organization
JIS – Japanese Institute of Standardization
SAE – Society of Automobile Engineers, USA
Standard ISO 1585 tries to bring all of those standards together, but the difference up to 10 percent still exists.
Power measured by DIN is 1-3 % smaller if recalculated to ECE or ISO. This explains BMW M3’s 333 PS and 325 HP, 2.5 percent difference.
There are also two different types of power: Netto power and Brutto power. Netto power is the power produced by the engine on the dynometer at the flywheel with all of the needed equipment, such as alternator, exhaust with catalytic converters and all the pulleys. Brutto power is the “laboratory” power produced by the engine, where the engine is not equipped with all the needed equipment for the vehicle operation. Typically Brutto power is 10-20 % higher than Netto horsepower.

New J1349 changes the SAE method. Old SAE standard of measuring horsepower measured the Brutto power of the engine, MINUS the calculated by engineers frictional losses on pulleys, alternator, power steering pump and thermodynamic loses of slow down of the gases by the exhaust system. Any oil level, octane number of gasoline and atmosphere conditions could be used. J1349 uses more strict methods, as the engine oil level has to be filled top level (less oil created less internal friction), octane number of fuel used has to be the same as in the manual (there is the whole story of measuring octane numbers, as well: in the USA highest octane number is 95, Europe 98, Japan 105).
The third party person, who signs off the result, makes sure that atmospheric pressure, air temperature and the octane number of fuel are at the right number.
From January 1, 2005 standard J1349 becomes mandatory. Though if the engine family does not change, manufacturer doesn’t have to change the rating based on a new system. Some manufacturers like Acura adopted the system willingly.
J1349 is just a new way of measuring the power. Honda Legend with J35A is still 300 PS, Honda Integra Type R with K20A is still 220PS, unlike RL, RSX type S and Civic SI with identical engines (290hp and 198/201 hp).

As much as I love Nissan Motors, they have a loophole.
Nissan’s famous VQ35 engine is made in Japan. This engine used in Nissan Skyline, Altima, Maxima, Infinities: G35, M35…) rates maximum of 300 hp based on JIS standard (Nissan Skyline/G35 Coupe). Converted to American horsepower from metric horsepower, from JIS to SAE, using lower octane number this number will drop. Only is the Nissan chooses to adopt the system willingly or changes from the VQ35 engine family to adopt SAE J1349 standard of measurement. I dynode 2003 Infinity G35 rwhp at Dynojet at 231.9 hp at 6200 rpm and 222.9 at 4660 rpm and 2003 Nissan 350Z rwhp at Dynojet at 241.0 hp at 6220rpm and 236.5 at 4810 rpm.

On the other hand Acura’s J32A3 is American made. There is no analogoes engine in Honda line up. So it has to conform to SAE standards. I dynode Acura TL fwhp at 219.6 hp on a Dynojet at 6250 rpm (using 98 octane fuel, 19.5 degrees Celsius and 1012 mbar atmospheric pressure) and 198.1 ft-lb at 4990 rpm.

According to Sir Issac Newton Force equals mass times acceleration. With less power Acura apparently has a superior power train if it has 5.9 second 0-60 mph acceleration weighing at 1615 kg (3499 lb) (I cant shift that fast though), while 2004 Nissan 350Z has 5.3 seconds (1515 kg), Nissan G35 sedan – 6.2 sec, coupe –5.5 sec. (1580 kg and 1600kg).

This part of the article expresses my personal opinions, based on educated guesses, but should not be read as facts, as the prior informational part.

So why change the SAE standard. If you read “sensational” article ASIANS OVERSELL HORSEPOWER by Jeff Plungis / Detroit News Washington Bureau, you noticed the absence of German cars and Nissan from the list. Nissan uses JIS standard which does inflate horsepower, as I found out from my Dyno tests of VQ35. German cars use DIN standard. Who rejoices by introducing SAE J1349? You see the answers from that table. Two of the dying Detroit’s big guns need all the help they can get. I love American cars, but by being a mechanic I learned all about the quality of GM’s and Ford’s products. This reminds me of 400 hp!!! “monsters” under the hood of the muscle cars of the 70th, which under current standards of measurements can barely make 200 horses. As an engineer I realize that J1349 is probably a better measure of horsepower, but why change? We all know that SAE is the Society of Automotive Engineers of the UNITED STATES. Draw your own conclusions, but the answer is pretty obvious. If they wanted to measure the “real” horsepower they should measure automobile’s wheel horsepower and not the engine power, which would lower the power, but show the superiority of the Japanese power trains. (I am yet to see a descent American transmission). Detroit tries to overturn the losing battle that goes on for decades, where top three passenger automobiles on the market are: Toyota Camry, Honda Accord, Honda Civic.

[Headnsouth]

Thanks for the reply and article.