Posted on Sunday 20 May 2007
It’s been well documented that BMW’s new twin-turbo inline six from the 335i produces significantly more power than its official 302hp rating suggests. We reported earlier about a test of a brand new 335i Coupe on a dyno, which resulted in outputs from the motor ranging from 282 to 300hp at the wheels. Estimating drive-train loss of roughly 15-20%, this equates to roughly 350 to 375hp at the flywheel. The publication that ran the earlier tests on the BMW, Automobile Magazine, has now run Infiniti’s new G37 Coupe on the dyno and achieved some exciting results for the 3.7L V6.
The new motor debut’s Nissan’s VVEL technology, which uses infinitely variable valve timing adjustment, similar to BMW’s Valvetronic system. The official ratings stand at 330hp and 270lb-ft of torque, although Infiniti is yet to release finalized peak output ratings. Tests on the dyno reveal that the new VQ37 produces 22% more power than the smaller VQ35 from the previous G35 but is only 5.6% larger in displacement.
The dyno charts also reveal that the new 3.7L unit produces a flat torque curve from 2,000rpm all the way until 5,000rpm and is still producing 85% of its peak torque at redline. The engine is also rated at having just 37hp more than the previous 3.5L motor but developed 51 more horses on the dyno. Taking into account driveline losses of 20-25%, we’re looking at a flywheel figure of around 365hp. Bravo Infiniti.
Estimating drive-train loss of roughly 20-25%… sure. So there is more than 50kW of losses in the transmission. That’s a pretty big radiator: the one next to you in your office is probably rated at 3kW. The gearbox should be red-hot and the tires would be liquid now.
Seriously, the transmission losses are typically around 10% in a modern car, 5% for a manual gearbox and 5% for tires, and that’s enough to warm them sufficiently. So the dyno 287hp is in line with the 330hp claim. The augmentation from the previous engine could be because the G35 was over-rated.
Still the torque advantage is BMW. A lot more of it, a lot earlier in the rev range.
The Japanese have a history of over rating the engine output.
Nice car though, no doubt.
torque converter, differential, weight of all spinning parts…
I know BMWs are about 15 to 20..
15%for the manuals..
20% for the steptronics..
it doesn’t really matter what hp the car has at the flywheel…
25% loss is.. quite a lot..
I can’t see the driveline loss being that much, but those are some sweet numbers for sure!!
http://6mt.net
dyno readouts are worthless, you can make a dyno graph draw a picture of a house if you wanted..
I have to agree with surok on this one. Dyno results are heavily affected by the type of fuel used, how much air is blown in front of the engine and ambient temperatures.
There’s only one true measure of performance and that’s at the end of a quarter mile.
Anyone willing to drag a G37 with the 335, i know i woould
I have a good feeling the new G will dust the 335i