I'm not doubing that it might be more powerful, I just want to see how they compare.

 

Somebody do the HR on a Dynojet please. I want to see power to the pavement, not the hub.

 

Not really, they look just about the same on paper, just need to see real world results. Gearing has alot to do with it as well.

 

Morning guys;
The DYNO numbers don't mean anything to me! Show me 1/4 mile slips!
The new engine looks good on paper(ie: dyno results) but until it's at the track, who cares! Take your cars to the track, not to the dyno shop!
Have a great day!

 

But, why does the G35 have a quicker 0-120 MPH time?

Road & Track Data (Same Test Conditions)

0-30 MPH
(1.9 Sec vs. 1.9 Sec)
Equal

0-60 MPH
(4.9 Sec vs. 5.4 Sec)
IS350 is faster

0-120 MPH
(19.5 Sec vs. 19.8 Sec)
G35 is faster

The IS350 has stepless upshifts, wider rear tires (255 vs. 245), and shorter gearing than the G35. The IS350 also makes its peak power at 400 RPM less than the G35.

Also, why doesn't the 2GR-FSE make more HP than the VQ35HR? The 2GR-FSE has direct injection, a higher compression ratio, and a larger stroke volume.

 

Does it have dual intakes, teflon coated pistons, dual throttle bodies, equal length shorty headers though? I agree the IS350 is geared more agressively not just the rear end but the 6 speed auto as well. Put those in the G35 and it should be faster.

 

The "Flywheel" designation for power and torque by the Dynapack software is technically correct. For that matter, the numbers you get from DynoJet, Dynodynamics, or whichever dyno are also technically "Flywheel" figures minus the drivetrain loss (aka transmission loss).

Do you really think 250 ft-lbs of torque at the rear wheel is able to sufficiently propel a 3300+ lbs. car from 0-60 in under 6 seconds? Try 60+ seconds. The actual torque measured at the rear hub or wheel is many times greater. It has been converted back to the "flywheel" figure via the gear ratio, so the rest of the average Joe can understand it. If anyone's interested in the actual torque measured at the wheel (hub), I'm sure Tony wouldn't mind sharing them as the Dynapack software measure those natively.

The Dynapack software also goes a step further by allowing transmission correction factor (tcf) for actual "flywheel" numbers. However determining transmission loss is tricky at best, so most operators leave it at the default correction factor of 1.0 (no correction).

Hope that helps.

 

Multiply out the gear ratios.

IS350:
Redline: 6600
Final: 4.083
1st: 3.52 (14.372 final) (35.1 mph top speed)
2nd: 2.042 (8.34 final) (60.5 mph top speed)
3rd: 1.4 (5.71 final) (88.25 mph top speed)
4th: 1.0 (4.083 final) (123.55 mph top speed)
5th: 0.716 (2.92 final) (172.55 mph top speed)
6th: 0.586 (2.39 final)

07 g35 6MT:
Redline: 7500
Final: 3.69
1st: 3.79 (13.99 final) (3% taller than is350)
2nd: 2.32 (8.56 final) (3% shorter than is350)
3rd: 1.62 (5.98 final) (5% shorter than is350)
4th: 1.27 (4.69 final) (15% shorter than is350)
5th: 1.0 (3.69 final) (26% shorter than is350)
6th: 0.79 (2.92 final) (22% shorter than is350)

07 g35 auto:
Redline: 7500
Final: 3.69
1st: 3.54 (13.06 final) (9% taller than is350) (45.7 mph top speed)
2nd: 2.264 (8.35 final) (same as is350) (71.46 top speed)
3rd: 1.471 (5.43 final) (5% taller than is350) (109.98 mph top speed)
4th: 1.0 (3.69 final) (10% taller than is350) (161.78 mph top speed)
5th: 0.834 (3.08 final) (5% shorter than is350)

You can tell that the 5AT g35 definitely has longer gears, and a taller final drive. But 5th and 6th in the lexus are overdrive gears. The lexus has to shift to second 10mph before the g35, so the g35 has the gearing advantage for 10mph. The lexus also has to shift to 3rd about 10mph before the g35. Again, the g35 has the gearing advantage for another 10mph.

Then it gets interesting. The lexus shifts to fourth, is 1:1 gear, at 88mph. After this, the g35 enjoys a shorter final gear ratio for almost 22mph. For that 22mph, the g's final gear ratio is 32% shorter.

That's why it's faster to 120mph.

Of course, all the previous information is based on stock tire sizes and stock redlines.

 

Depends on the track. and the 60'. and the tires. and the elevation..... yadaydada. to many variables. I spun the tires, managed a measly 2.5 60' and a 15.1 at 98mph, doesn't mean that's what the car is capable of, I just messed up.

 

I'm going to dyno my G once I rebuilt my subi and it's ready to tune, I'll post the results.

 

When are we going to see the 6MT dyno????

 

Interesting that the Lexus 2nd allows 60.5 mph; what a coincidence that it doesn't have to shift twice in 0 - 60

 

Practically EVERY car mfg does this so that their cars generate the best 0-60 times.

I think Lexus's gearing makes more sense than what Infiniti chose for the G35. The 6 speed G35 hits 69 mph in 2nd and 98 mph in 3rd vs. 60 mph and 90 mph for the Lexus. Thus, it appears if the G was geared shorter, its 0-60 times would be as quick as, if not quicker, than the IS350's times.

On the top end, the G35 has a relatively short 6th gear which causes the car to rev at 2400 rpm at 60 mph when the IS350 is only turning 1950 RPM at 60 mph. This relatively short 6th gear gives the G worse gas mileage for not useful advantage in acceleration. Since the G already hits top speed in 5th gear, you would think Infiniti would have spec'd a tall 6th gear for good freeway crusing gas mileage.

 

If it were "flywheel hp" it would not include the transmisson loss. But how would this reading be able to compensate for the transmission, driveline and axle loss? From what I understand, the number is a wheel or hub hp reading but it is calculated based on the final drive ratio of the gear you are in. So it is not flywheel hp. If it were, it should be higher.

 

I agree... it appears they really shot themselves in the foot on this one. Here in the US, the 2 important measures are 0-60 and 1/4 mile... the longer 2nd gear doesn't allow you to keep it in 3rd for the 1/4... you still have to shift to 4th. And then still have a short 6th gear for crappy EPA ratings? WTF? With gas costs and everything else... it doesn't make sense.

Only if the engine starts to really drop in power towards redline does it make sense to keep 2nd gear that much taller... but maybe that is why they did it. I don't think so, though.

It seems like shorter gearing and a taller 6th would benefit this car in many marketable areas, both performance and then EPA ratings. Based on power curves, there may be a reason for the 2nd and 3rd gear ratios... but I see no reason for the short 6th gear since it tops out in 5th anyway. Except for a slightly faster feel in 6th... which I think is less important than a 2 mpg increase in highway ratings.