So... then parachutes work better than mechanical methods since the mechanical methods are not productive, like I already stated in not so many words. All you did was confirm my statement and add more info. I don't need to read up about it. The bottom line is that aerodynamic force is enough to slow a car down, so aerodynamic force also has the ability to hinder a car's acceleration.

Quit digging for reasons to start an argument.

 

I see where you are coming from, but there is a fundamental error in your argument. The equation of motion in the horizontal plane in this case factors only in the mass of the vehicle, not its weight or normal force. Mass is a constant, you cannot add to mass; weight or normal force however is not a constant. The definition of weight is the mass * acceleration due to gravity, and since aerodynamic force is not a gravitational force, technically there is no increase in weight. What you are discussing is the normal force.

Slower ET/trap could result from increased rolling friction and increased aerodynamic drag. Nissan indicates the same 0.30 coefficient of drag for the Nismo 350Z as the standard/enthusiast/touring 350Z, so there should be no impact there. Rolling friction however does depend on the normal force.

According to Wikipedia, rolling resistance for an automobile on tires on a smooth road is roughly 0.01. Lets say its double that at a drag strip. At 100mph, for your calculated ~150lbf increase in normal force, that would give 3lbf increase in rolling resistance. In comparison, at 100mph, aerodynamic drag would be on the order 300lbf, and the total rolling resistance on the order of 70lbf. So the impact of increased normal force due to aerodynamic downforce in this case would be less than 1%.

 

I have done more research on this and I will concede to your argument in respect to mass vs. weight. I actually found an article on a website about sailing where they were able to increase the weight with aerodynamic downforce which allowed them to increase the size of the sail which allowed them to reach faster speeds since the added weight didn't require more force to move. But, with the added downforce came added drag, but the difference in sail size overcame the drag (essentially having a bigger engine).

Now, I looked into the fundamentals of downforce vs. drag and found this article from tuner performance:

http://www.tprmag.com/issue/13/13_aerodynamics.shtml

After reading this article I conclude that Nissan is either lying about the coefficient of drag for the Nismo, or it's a typo/mistake. For one, how does the Nismo have the same coefficient of drag as all the rest of the models (.30), but the Grand Touring has .31 instead of .30 with that little spoiler vs. that huge spoiler? Both models have the undercarriage package as well. It's not possible. I quote:
Also quote:
So how can the Nismo not produce more drag when the downforce difference is quite large? Also, how can the Grand Touring have more drag with that little spoiler? I may email Nissan and ask them this.

 

the underbody package reduces drag, the underbody package is there to decrease lift by smoothing the air flowing under, which in turn reduces drag. i think that helps even it back out to the .3

 

The Grand Touring has the rear-diffusers and front chin as well, but a small spoiler and still has a bigger drag coefficient than the Nismo. That's a good guess, but it's not possible.

Reducing underbody drag will not overcome the drag produced by a big airfoil. There is little room for improvement there on a Z, any model. Just take a look under your car sometime. Which is why the Grand Touring has a coefficent of .31 even with the underbody package and having that little spoiler. How much drag do you think that little spoiler adds? (I'd guess next to nothing) So how much drag do you think the underbody package recovers since the GT spoiler still adds to the coefficient of drag even after the underbody kit? Obviously not enough to lower the CD for the GT with a little spoiler...

 

And we wonder how the Z has a lower CO than a Corvette C6. LOL.

It's all in the design.

 

All 350Z trim levels have the same body design, so that comment makes zero sense.

Post away, I'm waiting for a response from Nissan as well as a few other places in regards to this. I'll be posting their responses here.

 

Kuah, it's okay, this guy argues to no end with everyone on this site because he always thinks he is right.

Ummm all in the design of the body kit. Wow are you really that lost.

 

Thus far 45% of the voters disagree with the 25% that you voted with... So who's wrong here? The majority? We'll see what Nissan says. Apparently I'm not the only person who thinks he's right since you argue just as much as me. Hypocrite.

Go get a timeslip.

 

Exactly, the same principles of most racecars -- a lightweight car with as much downforce as possible gives the highest cornering speeds.

It could be a mistake, but its not that clear cut that its drag coefficient should be higher. The front bumper and especially the rear bumper/diffuser may reduce drag over the stock design. And the Nismo 350Z and the Grand Touring wings do not generate alot of downforce (a real GT race car wing would generate over 500lbs of downforce at 100mph), so their drag impact may not be that large.

 

You don't see me arguing now do you? Others have even said also that is all you do is argue. Anyone can research your posts.

Calling people names now? Wow.

 

I did not remember seeing the .31 number, so I looked it up on Nissan's website again:

http://www.nissanusa.com/z/specifications-coupe.html

It states 0.30 for the standard/enthusiast/touring and Nismo, but 0.29 for the Grand Touring.

 

Ah, okay. I haven't looked for a while but thought it said .31. In any case, I knew it was different than the rest. I guess the rear-diffusers and front chin knocked off .1 more than the little rear spoiler added, which was maybe .1 (just guessing).

I would think that the Nismo spoiler adds a lot more though. I'm sure that I'll get a detailed response from Nissan about the aerodynamics considering that I had to provide one of my VIN numbers from my two 07' Z's in my contact information, and added the second just because. I'll post whatever they say to me here if it's relevant to this discussion.

You were saying? Yes, you are arguing which is why you keep posting argumentative posts. You're the one starting stuff here in this thread. Just like you did here by putting words in my mouth and saying that I said the Nismo was a 14 second car. You also started the name calling in that thread and it wasn't as nice of a choice of words as mine. Anyone can search your posts too and see who's the trouble maker here. You've deliberately searched my name and tried to start an argument with me and/or bashed me in every recent thread I've posted in. But I doubt anyone cares enough about you to bother searching.

Isn't there some kind of forum rule about stalking/harassing members? You're too childish to keep an argument contained within that single thread and you have to carry it into every thread the member posts in? Grow up kid. If all I do is argue as you say then why don't you stay the hell away from me? Perhaps because you're looking for an argument?

Stay away from me. Can I say it any more clearly?

 

I have searched your thread? lol. That is too funny. Anyone can see you don't argue with just me, you argue with almost every single person on this site and the admins are already watching you. Keep it on.

Kid? Funny, I am even older than you.

 

Yea lets just talk about timeslips. Your timeslip says 13.5. Thats it. Thats all your car + driver is capable until proven wrong. Dont claim to others your car can be a low 13sec car by what others have achieved. Lets see you replicate the same timeslips then you can argue afterwards. Until then your car is on part with a stock automatic HR Z and a Nismo Z. Case Closed
/thread

 

Sooo..I will go ahead and do a search on your threads...and prove how annoying you are.

Threads 2007-Z has been hostile in.

https://my350z.com/forum/showthread....82#post3581282

https://my350z.com/forum/showthread....38#post5085438

https://my350z.com/forum/showthread....11#post5073011

https://my350z.com/forum/showthread....12#post5093712

https://my350z.com/forum/showthread....65#post5089665

https://my350z.com/forum/showthread....14#post5089014

https://my350z.com/forum/showthread....98#post5119298

https://my350z.com/forum/showthread....02#post5140402

https://my350z.com/forum/showthread....45#post5156645

https://my350z.com/forum/showthread....51#post5156151

https://my350z.com/forum/showthread....31#post5147931

https://my350z.com/forum/showthread....88#post5204288

 

Agreed. His is actually slower than the NISMO Z as someone else pointed out. The NISMO has actually ran a trap of 103 something.

I will be headed to the track in the next few weeks. So it's all good. I will put the stock filters back in before I go.

 

i raced a nismo stock for stock on the highway 30 to 150, my car had a steady pull the whole time, ended up beating him about two cars. It had alot to do with down force i think.

 

2 cars? LOL. Well, you have mods.

 

I think it has more to do with the driver. This is a stupid argument. Its the same damn car guys.