What distance does it typically take a HP car to reach top speed?

[Hemirunner]

A physicist I saw on a site on Google calculated for a decently aerodynamic car,( he used a corvette as example) it takes approximately two and a half times as much power to go from 150mph to 200mph.
So, if your roadrunner can do 150 with 335hp, you will need somewhere near 800hp for that deuce. That is just drag, not Including rolling resistance.

I’m somewhere around 1000hp at the flywheel and It’ll rev to 7500rpm. The top speed potential is 214 without taking aerodynamics into the equation.

 

[33 IMP]

I’m somewhere around 1000hp at the flywheel and It’ll rev to 7500rpm. The top speed potential is 214 without taking aerodynamics into the equation.

And some people think a stock superbird is a 200mph car..

 

[dvw]

I hate to burst anybody's bubble. But the chances of a near stock B-Body going 150 are pretty slim. Check some of the top speed events and see what it takes to do 150. More than you would think. As for stability my 64 Belvedere sedan tops 145 every pass. It has been 150 in the 1/4. Drives fine with stock front suspension. My sons 62 Savoy has been 142, same thing, drives great.
Doug

 

[Hemirunner]

I hate to burst anybody's bubble. But the chances of a near stock B-Body going 150 are pretty slim. Check some of the top speed events and see what it takes to do 150. More than you would think. As for stability my 64 Belvedere sedan tops 145 every pass. It has been 150 in the 1/4. Drives fine with stock front suspension. My sons 62 Savoy has been 142, same thing, drives great.
Doug

I don’t think anyone has made that assumption. I read the question as a high hp B-body even though Tim left out the word high. Maybe the hp is to mean high performance. Either way, I figured he asked the question with his own car in mind.

 

[69 GTX]

You got it right Mike!

 

[IQ52]

I was thinking my 69 GTX with 3.73 + gearvendor (3.10 ish) might go 150 mph, I figured (guessed it'd take 1-1.5 miles to do it. Probably will never try it around here, to many critters to pop out of the ditches!

Pop went from 146.10 in the mile to 150.246 in three miles. Roughly, you are good for 165 in two to three miles. You're about 400 horsepower short of 200 MPH.

 

[5.7 hemi]

When does gearing come into play?

 

[33 IMP]

When does gearing come into play?

Always! ( sorry, wiseass attack)

 

[5.7 hemi]

Let’s say you need 800hp to hit 200mph with 3:31’s and you drop the hp to 600 and run 2:76’s. Can it be done?

 

[Hemirunner]

Let’s say you need 800hp to hit 200mph with 3:31’s and you drop the hp to 600 and run 2:76’s. Can it be done?

http://www.wallaceracing.com/Calculators.htm

This should keep you busy for a while lol

 

[BSB67]

Let’s say you need 800hp to hit 200mph with 3:31’s and you drop the hp to 600 and run 2:76’s. Can it be done?

No. You cannot swap one for the other.

 

[5.7 hemi]

Why not? It’s done for drag racing, cruising and stop/go type of driving.

I know you need X amount hp to get to a certain speed, so wouldn’t gears give you more top speed?

 

[Hemirunner]

Why not? It’s done for drag racing, cruising and stop/go type of driving.

I know you need X amount hp to get to a certain speed, so wouldn’t gears give you more top speed?

Assuming the engine will rev to 6650rpm with 2.76 gears, 26” rear tire while bringing along the full weight of the vehicle AND overcome the aerodynamics, it’ll go 200mph. Alot is going to depend on the vehicle weight and aerodynamics.

 

[5.7 hemi]

I gotcha, thanks!

 

[BSB67]

Why not? It’s done for drag racing, cruising and stop/go type of driving.

I know you need X amount hp to get to a certain speed, so wouldn’t gears give you more top speed?

Do gears make horsepower? No.

Your statement would only be true if you had the wrong gear ratio to begin with and you ran out of rpm before using it all. An example of this would be a 440 hp with 4.10. Its top speed would be dictated by the gear. But in this discussion, the presumption is the gearing is correct.

Also, accelerating a car quicker is totally different than top speed. See car people get this wrong when they start working on boats.

Gear ratios and rpm aside, if it takes 800 hp to make a given car go 200 mph, that is what it takes. Gear ratios don't make hp, but will effect how long it will take to get to top speed, and top speed will be achieved when you either run out of rpm, or run out of hp. To get 800 hp to go 200 mph, you will need the the correct gear so that the engine achieves it's maximum hp rpm at the 200 mph, generally speaking.

If the physics allow you get to 200 mph with 600 hp for a given car, then 800 hp will get you to something like 220. But if in that car the 800 hp only goes to 200 mph, its because it has the wrong gearing.

Also, at the 1/4 mile track, gear ratios don't really change the trap speed (mph), only et. This is why using track mph and race weight is the best method for estimating hp.