Cant wait to see the vid-congrats to all...best part is your all safe, and the car is issue free!

 

Congrats to the both you! I thought 159 mph was fast, 183 mph is just crazy fast!

 

The weight isn't whats holding him back... It's drag.

Theoretically, you can figure out how much power you need to go a certain speed by a formula...

Power = velocity^2 * drag coefficient * frontal surface area * density of the air.

Isn't Brent's car a convertible? Drag is probably killing the 200 mph goal.

 

What is the drag coefficient of our Z's

 

0.30 for a coupe, 0.34 for the roadster.

Doing things like removing the side mirrors should help a little.

 

you guys had helmets on, right?

 

okay, I suck at math what power would a stock bodied Z (coupe)need to get to 200mph then. And wouldn't gearing have to be a variable also.

 

i've been to 180+ a couple times

 

Gearing does play a part in top speed, up to the point that (and I don't know how to explain this properly) it cannot accelerate through the air faster than the air slows it down at such high gearing.

i.e. a lot of high performance 6mt cars' top speeds are made in 5th gear, not 6th. Gearing the car too high will hinder it's ability to overcome the amount of aerodynamic drag imposed on the car.

 

On your bike lol

 

lol.. yeah

 

very cool guys!!!!

 

That is only true in the case of a car where shifting into the next gear would lower the power output (due to changing RPM) to a point where it could not maintain its speed at the time of the shift. Torque is irrelevant in top speed calculations, so high gearing doesn't matter, so long as the car's top speed isn't limited by overly short gears.

In the example given, those cars that topped out in 5th would probably have had a higher ultimate top speed if they had shifted directly from fourth to sixth. It would have just taken a while to get there..

 

hell no...

they were doing the passes with the top down, drinking beer and passing a fat doobie.

Helmets won't do much good when they hit the 184mph mark.

 

At sea level, using some stats given above and the published wheelbase and height of a 2006 350z, taking both the force of air resistance and rolling friction into account, Brent's car should require 545 horsepower to the wheels to maintain a constant speed of 200 mph. He would require a bit more to actually accelerate and get up to that speed in any reasonable amount of time...

How much horsepower was he running? I think it was posted somewhere but I can't seem to find it...

EDIT: For those interested, a base 350z weighing 3400 lbs would require only 473 hp to reach the same target speed. A 3600 lbs G35 coupe would require 470 hp (coefficient of drag is 0.28 vs. 0.30 for the z). I've double checked these #s and they look right but if anyone catches an error, let me know. I used 0.03 as the coefficient of rolling friction, which was what wikipedia listed for a street tire on asphault. This was a nice physics exercise - been a long time

 

Glad yall are safe thus far, and the car seems to be running smoothe. Good job!

 

doesn't he have big wings and bodykit action going on? the factory body/bumpers/wing (no wing) would probably be better for this kind of racing. narrower wheels/tires would help too.

 

Congratulations Brent and Sharif for a tremendous first try. 183mph in a convertible is a tremendous feat! Well done!

I think the fact that they went this fast in a convertible is amazing. When you look at all the cars designed to go fast down the old Mulsane straightaway at LeMans, they all had long extended tails with gently sloping roof lines... exactly what a 350Z convertible is not. Makes it a little more special.

 

The air drag is constituting about 88% of the total resistance force and rolling friction (which is weight and tire dependent) only contributes the remaining 12% or so. So yes anything that increases the drag coefficient has a big impact (each hundreths place, say 0.29 vs 0.30, seemingly has just as much impact as 400 lbs of weight!).

 

Ah.. an error. Bonneville is a salt flat, a lose granular surface w/a hard pack underneath. Think a light dusting of snow over a frozen dirt road. Last time I drove on the flats I could feel the tires fighting for traction and yet sinking into the salt biting forward. It's a strange sensation to say the least. Needless to say, not the greatest surface for traction or rolling resistance.

Also the elevation is ~4218ft ASL