tekk

interesting, for some reason i thought they set the f/d to the same 3.5 we have now. the article does state that its 3.69:1 though.

when you rev the engine higher, a side benefit is that you can have a higher theoretical top speed. 160mph was probably enough for nissan though, so they raised the f/d and took the hit from whatever the top speed would have been (175?) to make it 160, so they could benefit from added torque across the entire curve.

i cant see them doing anything different for the z. the new VQ35HR should be a nice engine to mod....dollar for dollar, the z may even keep pace with the 335i...

clarkkent06

iTrader: (1)

"so they could benefit from added torque across the entire curve."

technically, the final drive has nothing to do with an engine's "curve" at all. by raising the final drive, increased acceleration will benefit, as well as the ability to keep it at higher rpm's on a track. however, the engine remains unchanged.

ihatethatbobbarker

assumed he was talking about an sr in a Z since there was an SRFD in his sig.

bghoward

the higher redline won't affect top speed, remember the Z is already geared for 190+mph, in fact going with a 3.9FD will actually give the Z a higher top speed because it is drag limited and the extra gearing gives it a little more oomph at those speeds. The biggest benefit to higher redline is take better advantage of it through gearing.

Think of it this way would you rather have a Z that pulls just as hard as the current one only longer, or would you rather have a Z that pulls just as long only harder.

7500 / 6600 = 1.136

we could gear the car ~14% shorter and still shift at the same speed.

3.79*3.56 = 13.4924 current 1st gearing ratio
13.4924 * 1.136 = 15.3273664 theoretical new 1st gearing ratio

287/274 vs 306/270

274 ft/lbs * 13.4924 = 3696.91 rwft/lbs
270 ft/lbs * 15.3274 = 4138.39 rwft/lbs (and a flatter curve)

streetracer

iTrader: (1)

steven88

its rated at 306/270 on the new HP system correct? but if we used the old system, then it would be about 5-7hp/tq higher? at least thats how I see it

so the current Z is running at 300hp on the old system...the new vq35hr Z would run maybe 312hp on the old system? 12hp increase....ehh, you guys think nissan would bump it up a lil more when they release it for the Z? 12hp don't sound much especially for 80% new internals....i was hoping for 20 (this is all under the old hp system)

tekk

i did not mean to say that the curve would be modified in any other way- only that you'd be putting more turque on the ground, at all rpms. correct me if this is wrong..

I have an 04 G coupe 6MT. My car doesn't appear to be geared for 190+mph. I think I'd hit redline in 6th at 160mph. The only way I could see myself going faster is if I had more rpms and more power to use those extra rpms. I agree with you regarding gearing & redlines...

tekk

i wouldnt try to translate the old system to the new one..that would make it even harder to compare power with other cars.
udner the newer standard, the nonrevup engine is ~275hp and the revup engine is ~293hp. the new engine is now ~306hp. The power increase and curve/gearing changes should be more significant than the 12hp difference suggests though.

look at it this way: the G35 sedan went from doing the 1/4mi in about 14.6@98mph to about 13.9 sec @ 103mph. That's a big change.

Now think, they're putting that engine in the Z next...

bghoward

245/45/18 tires are 245cm*0.45 = 110.25 cm / 25 = 4.41 inches

the sidewall is roughly 4.41 inches

4.41 + 18 + 4.41 = 26.82 inches diameter
circumference = PI * D = 26.82 * 3.14 = 84.26 inches

6th gear is 0.794 and the FD is 3.538 = ~2.81 final ratio

6600rpms / 2.81 = 2348.75 wheel rpms at redline in 6th gear

2348.75 wrpms * 84.26 inches = 197,906.05 inches/minute
197,906.05 / 12 inches = 16492.17 feet / 5280 = 3.124 miles/minute

3.124 miles/minute * 60minutes = ~187.41 mph


Nissan could have bumped the engine to a 3.7L, but...

Well with the new true dual symmetrical intake, symmetrical exhaust, strengthed block, better cooling, higher revs, better friction management, etc-- I have news for you, those things weren't developed for the G35 sedan, they are just trickle down R&D...

Also like I said earlier in this thread the 306hp IS350 is putting down 260-265rwhp with an automatic. The new SAE system should reduce mfgr to mfgr horsepower discrepencies, so I would estimate at least 265-275rwhp for the new engine with the 6MT.

From what I have seen the old G35 sedan would put down about 225rwhp so 14.6@98mph to 13.9 sec @103 quoted earlier is about right for 40-50 rwhp.

bghoward

forgot to mention, the rev-up Z/G would top out around 198mph in 6th gear. Remember 6th gear is not designed for achieving the cars top speed, it was designed to give it a reasonable bragging top speed and still get good mpg in cruising. Would you trade cruising 4000rpms@60mph for an extra 10mph top speed? I drive at 60-70mph all the time, I don't go 160+mph very often.

teknochild

your thinking is off the higher the rpms @ 60 the lower the top speed is going to be.....

bghoward

My thinking wasn't off...

In theory taller gearing allows you to achieve higher top speeds and will allow a lower cruising rpm. however the Z is never going to achieve 190+mph it is geared much too tall and doesn't have enough power to overcome about 160mph with stock gearing. My point is that if nissan had geared the Z for a theoretical top speed of 175 instead of 190, the car would actually have a little more oomph from the additional mulitplication of gearing and would more than likely achieve a higher top speed.

Think of it this way, if I wanted to acheive the maximium mph why would I gear my car so that in top gear I can only hit around 5500rpms or so before becoming drag limited? I wouldn't be using the full potential of my powerband. I would want to gear the car so that the car is drag limited at it's redline of 6600 rpms.

I have heard that getting the shorter 3.9FD gear actually *increases* the achievable top speed even though the theoretical top speed decreases.

n8236

For the lazy.

The nissan VQ engine new model article summary
The nissan VQ engine new model output 315PS

The Nissan Motor Co., Ltd. technical announcement did on the 22nd, the new “VQ” serial V6 engine. The fact that first it is loaded is the next term 'skyline which is announced to the fall'. If you mention “the skyline”, in the Japanese market whatever saying, the image of the sport sedan is strong.
2006 August 30th
Reflection to the NISSAN VQ engine new model type designation

Keeping the Nissan Motor Co., Ltd., full the new model V6 engine “VQ35HR” which it appears (3.5 liters in aerodynamic volume displacement), “VQ25HR” (2.5 liters in aerodynamic volume displacement). But very type the same as the current 'skyline' on-board machine VQ, in fact another engine is the NISSAN insistence.
2006 August 29th
Block
As for the NISSAN VQ engine new model 0-100km/h acceleration a little more than 1 seconds shortening

The Nissan Motor Co., Ltd. 22 days the new generation V type 6 cylinder engine “VQ35HR” which is announced (3.5 liters) with “VQ25HR” (2.5 liters), continual variable valve timing mechanism to inhalation and exhalation of air both sides (CVTC) raised largely with the improvement of advancement and the friction and pumping loss etc of control of the combustion with adoption, output and fuel economy efficiency in comparison with old type.
2006 August 22nd

n8236

My question is, what do they mean by 0-100 km/h acceleration a little more than 1 second shortening?

krismax

0-62mph 1 second faster example if old did 6 now it does 5

n8236

Impossible! lol If that's accurate (for the 3.5 engine), the car must of lost a TON of weight or something, haahah. That's 911 territory!

BluZee

I was just reading the new Car and Driver test on the 07 G35 and it trapped 103 in the 1/4 (13.9). Im dying to see what the Z is going to do with the new VQ.

steven88

wow, 315hp!?! this is under the new system...so i'm thinking 322hp...woot!