G35 Sedan V35 2003-06 Discussion about the 1st Generation V35 G35 Sedan

She has twins, greddy twins that is...

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  #2146  
Old 06-23-2010, 11:19 AM
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you cant consider the hp or drag coefficient separately when talking about reaching 200+. the question is if you have enough hp to over come the force of the air resistance at those speeds. the force is related to the drag coefficient, but the drag coefficient is not the end all be all. the bugatti veyron has a drag coefficent of .36 in speed mode and .41 in handling mode, both of which can hit 200+ easily. It can do so because it has 1001 hp. Like i said above the question is does tim's car have enough power overcome the drag force at 200mph. The drag force on an object can be determined from the following formula:
F=(1/2)*p*(V^2)*C*A
where p=density of air
V=velocity
C=drag coefficent
A=surface area

the power needed to overcome this force is:

P=F*V
where P=power
F=force calculated above
V=velocity

I dont know what the surface area of the g35 sedan is so i cant calculate exactly what the power would be. These variables are in metric

p=1.204 kg*m^-3 (at 20 degrees Celsius)
V=200mph=322 km/h
C=.26
A=?m^2

Hope this helps
 
  #2147  
Old 06-23-2010, 02:01 PM
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Well based on the sedan's drag and my power maybe it is possible to get up that high. Going off that spreadsheet with the drag and weight changed my car has 200+hp more than needed...
 
  #2148  
Old 06-23-2010, 10:34 PM
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Originally Posted by Andrei
That is not accurate at all. It doesn't consider wheel size or final drive or gear ratios.
Andrei, the tire size and gear ratios matter only if they conspire to keep the engine from producing the required HP at the desired speed. For example, "long" or economy-minded gearing might mean the peak HP isn't reached before drag takes over as the limit. Cars have been marketed that are actually faster one gear down from the top, because the top gear keeps the RPM quite low.

Conversely, a drag racer might run out of revs before drag is the limiting factor because acceleration is more important in that car than top speed. The top speed is then said to be "rev-limited."

All any mathematical solution can do is find the limit based on certain assumptions, and the assumption in that spreadsheet is the car is geared so that the developed HP is actually useful, and not just lurking at some high RPM the car can't reach in top gear.

The particular spreadsheet I posted attempts to find the HP required to overcome air drag at a given speed. Since the HP vs. RPM curve for everybody's engine is not known, that's about as good as it can do. That limit is implied in the column headings "HP required" for overcoming friction and drag, and the recognition in the formulas that not all the "flywheel" HP finally reaches the wheels. Those formulas make no claim that they also choose the right gearing to accomplish that.

All that said, it nailed the top speed of my MBZ 560SEC within 2mph.
 
  #2149  
Old 06-23-2010, 11:21 PM
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Originally Posted by ttrank
Well based on the sedan's drag and my power maybe it is possible to get up that high. Going off that spreadsheet with the drag and weight changed my car has 200+hp more than needed...
That's why it's not accurate IMO. And to have the stock drag coefficient you would have to replace the front bumper with a stock one. There is a 3.0 final drive Nissan makes that should yield 200++mph with no problem for a G sedan. 3.2 should work too.

Anyway. You are in Arizona next to the salt flats. Go try it.
 
  #2150  
Old 06-24-2010, 09:09 AM
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Originally Posted by Andrei
That's why it's not accurate IMO. And to have the stock drag coefficient you would have to replace the front bumper with a stock one. There is a 3.0 final drive Nissan makes that should yield 200++mph with no problem for a G sedan. 3.2 should work too.

Anyway. You are in Arizona next to the salt flats. Go try it.
+1

you'll never know unless you try
 
  #2151  
Old 06-24-2010, 05:28 PM
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Still have the stock speed limit for now.
 
  #2152  
Old 07-25-2010, 11:01 PM
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I remember reading this thread when I first joined, this was before I even got my G, and how this kind of lit the fire under my *** to hurry up and get one. Great build sir. Good luck in the future too.
 
  #2153  
Old 07-26-2010, 01:53 AM
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Thank you
 
  #2154  
Old 07-31-2010, 10:01 AM
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love this build. I have a c6, and this has almost double my RWHP. I'd LOVE to get a ride in this thing one day.
 
  #2155  
Old 07-31-2010, 02:29 PM
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You in AZ?
 
  #2156  
Old 09-01-2010, 04:37 PM
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hey what tape is this?
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  #2157  
Old 09-19-2010, 11:58 AM
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Superb as usual Tim. Good stuff!
 
  #2158  
Old 09-19-2010, 12:47 PM
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Originally Posted by nazc0
hey what tape is this?

Wow, old pic. LOL

That is header wrap. I was trying to keep the engine bay heat out of the intake.


Here's a more recent shot.

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  #2159  
Old 10-12-2010, 02:01 PM
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Amazing car. I can't imagine how much money went into that car since you started on it.
 
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Old 10-12-2010, 03:38 PM
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Me either. I try not to think about it.
 


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