What does it take to reach 300mph


Iconic GT

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Apollo

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Thanks for the article D. It's cool that others are realizing the significance of 300 mph in a street car. What most readers of these articles don’t realize is that Mark and his team did this from a dead stop in one mile. Any of these other cars attempting this would take many miles from a rolling start to try and match this. Mark almost hit that 500kph mark just from momentum through the gates and easily could have. One could only imagine the number if M2K had 10 miles of road like Koenigsegg did for their run.

Once again, hats go off to Ford for designing such an incredible platform, and to Mark for taking it to such incredible heights. A car design 15 years old that is still breaking records and setting benchmarks. Amazing!
 
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GTMD

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Yes, thanks for the article!

Now I'm no expert but the statement that said it could easily take more than 3,000hp to get a car to 400mph seems to be a gross underestimate. The HP requirements increase exponentially as speed increases in a fixed distance not even taking into account drag (also exponential) and increasing amounts of drag required to ensure adequate traction. Again, not sure what it would require to theoretically get to 400mph but I would tend to think we'd be talking about 5,000-6,000hp or more.

I know, I know...Forbes isn't a scientific journal but I couldn't help myself :cool:

Any physicists out there that could make a ballpark estimate?
 

PeteK

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The engineering rule of thumb is that drag increases as a square of velocity. THat's not exact because changes in air flow related velocity, such as transitions from laminar to turbulent flow, cause nonlinear changes in drag. But it's close good enough for a pretty good estimate for aircraft. Keep in mind that cars travel in ground effect--in fact, the ground effects have substantial influence on the drag and lift of the car--but let's go with the rule of thumb.

Let's commit some math in public: It takes about 2000 WHP/2500 BHP per Mark to get to 300MPH. 400MPH = 300MPH x 1.33 1.33^2=1.78. 1.78x 2000WHP = 3560WHP Delivering 3560 HP to the wheels requires about 4270 HP at the flywheel; give or take a couple hundred HP.
 
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GTMD

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The engineering rule of thumb is that drag increases as a square of velocity. THat's not exact because changes in air flow related velocity, such as transitions from laminar to turbulent flow, cause nonlinear changes in drag. But it's close good enough for a pretty good estimate for aircraft. Keep in mind that cars travel in ground effect--in fact, the ground effects have substantial influence on the drag and lift of the car--but let's go with the rule of thumb.

Let's commit some math in public: It takes about 2000 WHP/2500 BHP per Mark to get to 300MPH. 400MPH = 300MPH x 1.33 1.33^2=1.78. 1.78x 2000WHP = 3560WHP Delivering 3560 HP to the wheels requires about 4270 HP at the flywheel; give or take a couple hundred HP.

Fantastic! Thanks Pete!

The only thing missing from the calculation now is the increase in force required to simply accelerate the car more quickly (to a higher top speed) over the same one mile constraint. That is also an exponential factor I think. So even if the car was run in a vacuum (which wouldn't ever be possible), it would still take an exponential increase in power to push it to 400mph over the same mile as opposed to 300mph. Right?

Let me do a little research and see if I can figure that part out. Then if we sum the two deltas in HP, we should be in the ballpark. Lol...I can't believe I'm wasting my time trying to figure this out. I should be picking up more shifts to save for my NGT!
 
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GTMD

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OK, I ran the numbers using these equations:

a = (v2 − u2 ) / 2s
F = ma


Came out the exact same as your's Pete. I also realized that your's covers my concern about acceleration in a fixed distance. I still wonder if the increased drag needs to be calculated in though to get an accurate number. Nonetheless, it sounds like it would take at least 4,270hp at the flywheel to get it done, if not more. Yikes!
 
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fjpikul

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Since you guys seem to want to spin your wheels, why don't you waste more time on the coefficient of drag (CD) there are some really old threads covering all of this.
 

shesgotlegs

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Lol
 

GTMD

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Since you guys seem to want to spin your wheels, why don't you waste more time on the coefficient of drag (CD) there are some really old threads covering all of this.

Ha! Just a little mental masturbation going on!
 

TO AWSUM

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I wonder if the tires are warranted for 300 mph and how much they grew at that spped?
 

Specracer

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Absolutely not. Mark (Mk2) posted they are using Hoosiers and in uncharted territory.

I wonder if the tires are warranted for 300 mph
 

soroush

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I suspect the car is making way more than 2000hp to the wheels.
 
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MarkH

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I would have to agree with Soroush, the car is making "way more" than 2000hp to the wheels and to be honest in 5th gear running 50lbs of boost its probably north of 3000hp to the wheels. I am not sure where all these articles get their information and some of it is old information but Soroush is correct, the car makes well over the 2000 number as mentioned. Since I am NOT a big dyno believer, we just normally tune the car to a moderate number on the dyno and end up something a little short of 2000 and then run the calculations from the additional boost we still have to play with.... As for the tires, we do in fact run the Hoosier R7's and Hoosiers still states, they don't recommend going over 200mph in them and they for sure do NOT recommend what we are doing. Sure would be nice if we could get a little support from a tire manufacturer.

Hope this helps a little in the conversation..
 

Ed Sims

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Back in the day we would have a 3 page comment, that very few of us would understand, from IndyGT.

Ed
 

Specracer

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A recent cool article with some of the technical details about the car:

Amazing

 

THamonGT

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Great detail article! This vehicle will be at Keels & Wheels Concours de Elegance in Seabrook, Tx. This weekend on display with a great collection of Ford GT40’s and many Ford GT’s Of every year Model!
 

fjpikul

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I hear some deadbeat people from Fort Worth will also be there.
 

ChipBeck

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Gentlemen,

Knowing how much wheel weight effects acceleration I wonder if the car would have hit 300+ on 47 lbs of boost if the light weight forged wheels were used instead of the heavy cast wheels. Perhaps the team thought the car was more stable with those 4 heavier gyros spinning. Your thoughts on this Mark?

Chip
 

Vince H

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How great is it that you guys are talking about this for sh!?* and giggles and Mark comes on and validates the thinking? Best forum out there, bar none.

Vince H
 

MarkH

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Chip:

Yuu know I really never thought of that but I have several sets of the BBS wheels but for some reason we always run the heavy old school ones I guess because I think they look more like the old school GT40... Now you got me thinking, maybe we should only run the light weight BBS wheels and see what happens... Normally the way we think about each run is, if we need more power we just turn it up a pound or so more of boost. We have never been to the point where we have never had enough power that we even thought about the wheels as far as weight goes. I have a black set I had done and the original grey color that I don't much care for on the car... Guess that is food for thought...