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Auto/Manual Transmission?

What rpm is that at?

Remember peak hp is at 6000rpm on that engine.

Lets take a look, if 6000rpm calculates to 125mph(?km/h), this is an easy calculation on the manual(should be close on auto.), put it in 5th gear and drive at 3000 rpm, now note the speed and multiply by 2. This is speed is what it will do at 6000rpm.

If this number you get is 125mph and it takes 180 hp to push the car that fast through the air, the car will never go 125mph, it cannot produce that much horsepower, so it will only approach this speed and may top out at 115mph and be producing 160 horsepower.

As long as the hp at that speed is higher that what it takes to push it through the air it will go faster and vice versa, just because you cannot make it to peak hp rpm in high gear does not mean that it has a governor on it.
 

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spinnin' !
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The 3.5 auto is governed due to tire speed rating. The 3.5 5-speed has no governor. I've gone 148mph in a head wind. I think its good for right around 150mph when it runs out of hp sadly due to wind resistance probably. The car is very stable at that speed. It was still unnerving tho. I had gone that fast as a passenger but never in control of the car myself. Wooooo fun! :) I have only done this once and on a deserted stretch of highway at 3am. So I was careful. I hope everyone else will be too.
 

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Altimat said:
My 5-Speed does [email protected] which equates to [email protected] - given enough horsepower!!!:D
Actually you have to do the calculation at peak hp, which comes out to exactly 145 mph (75*5800/3000) this is a more accurate calculation because once you make it passed 5800rpm you are loosing hp. You can make it a little over peak hp, but not much.

This is the value that everyone seems to be coming up with. Right around 145mph to 150mph.


The only reason that the manufacture puts a governor on the cars is because the government requires them because the tires are not rated that high. H-rated tires will take 150+ mph if they are not fully loaded. Remember the stock tires will take around 1500 lbs. per tire. Speed rating is more of a load rating than a speed rating.
 

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Discussion Starter · #10 ·
e-squared said:


Actually you have to do the calculation at peak hp, which comes out to exactly 145 mph (75*5800/3000) this is a more accurate calculation because once you make it passed 5800rpm you are loosing hp. You can make it a little over peak hp, but not much.

This is the value that everyone seems to be coming up with. Right around 145mph to 150mph.


The only reason that the manufacture puts a governor on the cars is because the government requires them because the tires are not rated that high. H-rated tires will take 150+ mph if they are not fully loaded. Remember the stock tires will take around 1500 lbs. per tire. Speed rating is more of a load rating than a speed rating.
And besides, those police crusiers need to be able to catch us! :p

<j/k>

Joe :)
 

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Soundman said:
I think its good for right around 150mph when it runs out of hp sadly due to wind resistance probably.
Sadly, all cars run out of hp due to wind resistance. 95% of hp is going into moving the air from the front of your car. When they figure this one out you will be able to go faster on less hp.
 

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e-squared said:


Sadly, all cars run out of hp due to wind resistance. 95% of hp is going into moving the air from the front of your car. When they figure this one out you will be able to go faster on less hp.
What I meant by that was the car tops out due to aerodynamic limitations. As opposed to some cars which actually top out due to an rpm level reason.
 

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e-squared said:


Actually you have to do the calculation at peak hp, which comes out to exactly 145 mph (75*5800/3000) this is a more accurate calculation because once you make it passed 5800rpm you are loosing hp. You can make it a little over peak hp, but not much.

This is the value that everyone seems to be coming up with. Right around 145mph to 150mph.

I disagree. Drag increases directly with speed. The car will need a certain amount of HP to reach a given speed. If it requires 250 HP to reach 167 mph, a car may make that amount of HP at 6700 RPM if the peak is 275 at 5800.
 
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