So does mine, so what?? the tach takes over at that point, hey I didn't 1/2 believe it myself....which is why I hooked up a digital audio oscillator into a output transistor, on a clip lead hookup to the hei tach output, ignition on.....hei coil a sparking at various rates.....at idle each cyl fires 5X/second 600 rpm...once every other rev/300 div 60=5.......so times 8 and that's 40 hz...for electronics, that very slo....so verify tach reading....fllip controls for any speed and measure tach accuracy...this was all verified with a Tektronics 453 scope...line synch on trigger, so I know the count is accurate, no goof ups....
So 6000 rpm is 400 hz.....tach reads 300 rpm high..5%....

interesting that at 4500 rpm it's still high by 300 rpm....

so knock 300 rpm off the tach readings to verify speed, allow say 5% for tire slippage....

Very few modifications to the chassis/suspension really, just a VBP 460 front springs, Bilstein, urethane, steering is rack not that it matter a whole lot for a straight line shot....rear is just a VBP 360 spring I don't consider those simple modifications which MAY drop the car a inch, but that don't seem to be the case for ME.....those mods don't count for much.....

Hell, my wife's silly little 4 cyl Escort has maybe 90 hp if that, 2 liter engine....it will do 100 mph easy....there is no way in hell the frontal area/drag is much less than my '72 shark....

so I stick by my statement that 100 mph takes about 100 hp, and I was being generous before, and now....

 

i went 125-130 no problem with more left, it just got really squirly with original t-arms and such. i have a 385 with about 450-475 horse and a 700. stock 3:55 gears.

 

come on if my old stock 280Z Can get to 180 on some back country road i dont see why the vette cant go at least that fast.

 

TOTALLY agree. You can't just do a calculation of tire size and gearing to get you to 200mph. Wind and road resistance are a HUGE factor. As well as aerodynamics. Seriously, do some searches on top speed runs and see how much modification is needed to break even the 180mph mark. MUCH more than you think.
The c3, especially early c3, is like a brick aerodynamically. It sure looks sleek but in a wind tunnel it's terrible.

 

Hmmmm - indicated speed and real world gps verified speed can be totally different. My 06 Civic 1.8 I-Shift shows 128 mph on gps, but speedo says 140 mph!. My '68 L36 with tired 427 saw 135 mph but could have been 120 mph (rev counter indicated otherwise, but is that correct?) With new 489 & 3.08 rear end max rpm should mean 168 mph at just over peak rpm - would it do it? would I have the nerve? - would the front-end 'rotate'? - would the transmission and brakes hold out? - would the tyres hold out, (yes - it has 'W' rated rubber)

 

As a child of the 70s, I read just about everything printed about the Musclecars of that era. For starters they wern't 12 sec cars and most wouldn't do over 125 mph top speed. Speedos get very weird at higher speeds.
If it takes 200 rwhp to go 100 mph, it will take 800 rwhp to do
200 mph "4x HP = 2x speed". The aeros needed to go over 140-150 are critical. Small things like rearview mirrors and front spoilers become very important.
Those cars breaking 200 in the high speed events are old NASCAR racers that are already set up for high speed. Don't think that they don't get squirrely when they are not set up correctly.

The old F4 Phantom proved that a brick could fly w/enough thrust,
I would say 800 rwhp should make 200 mph. JMHO

Ricisan

 

Here's an old article which gives some real world feedback!

 

some other C3 corvette pics at Bonneville....

 

So how fast did these guys go?

 

My PT Cruiser will do 140MPH

Like some have said there is a big difference between 140 and 200MPH. My rear gearing and .64 OD computes to 285mph @ 7000RPM does anyone think my car will go that fast ? ( besides me )

Some of these vintage 600HP big block track only race cars cannot hit 200mph . I say it is possible but you need allot of track ( miles of it ) and allot of HP and the car setup properly

 

Yes, I ran the 93 mile silver state classic back when it was new and still a fun run what you brung kind of deal. Without credentials like SCCA competition license, blah blah, blah I was regulated to the 150 mph average class. They allow a top speed of 175 mph because of the slower sections to get as close to 150 average as possible.

What the poster is talking about is 0ne mile drag racing which is great fun. That is where raw Hp and some thought into gearing is king.

 

I read in an automotive aerodynamics book a number of years ago that it always takes 8 times the HP to double your speed. SO, if it takes you 100 HP to maintain 100 MPH then it will take 800HP to maintain 200 MPH.

 

I've been 155+ in my '81. And it only took my a 1/4 mile to get there.

 

Do a little research of the stuff running at Bonneville and what it takes to run those speeds ....some of you guys already have eclipsed some of the records and don't even realize it

"edit" Here ya go, take a look...

http://www.scta-bni.org/

 

I chickened out at 130mph in my '76, just too twitchy steering at that rate. I would think the #1 factor would be rear end ratio to get the top speed, then the hp. If your rear is low geared (drag not top speed setup) it wouldn't matter what hp you have, your max speed is limited by your rpm...1000hp running in a low speed rear end will get u to top speed hella fast, but wasted if you blow engine at 120mph.

 

How much money do you have?

 

I ran 160 (by the speedometer!!!) back in 67 in my younger stupider days in a 67 427/435 on Larado 2 ply tires. If I'd had a few beers I am sure it would of been at least 175. Not sure what the standard ratio of number of beers to speed is but.....

 

Dalannex is correct, the horsepower required does go up as the CUBE of the speed change. A car that requires 100hp to go 100mph would need 800hp to go 200mph (200/100=2; 2 cubed is 8).

 

So to go 160 one would need 410hp?

I think we are all little high on 100hp for 100mph

 

The supercharged ZR1 was clocked at 205 ish. That's with some 630+ hp in the tester, gearing and better aerodynamics.