Recent Topics
10/1-11/16 5 qt's Napa Synthetic w/Silver OF$21.99
by tenderloin
28 minutes 5 seconds ago
10/1-10/28 O'Reilly Sales Ad
by tenderloin
58 minutes 11 seconds ago
Got the Hi-Power
by john_pifer
Today at 12:03 AM
Upgraded Mobil Jet Oil 387
by syfi
Yesterday at 11:40 PM
klotz super techniplate feed back
by mcn1970
Yesterday at 10:58 PM
ISIS appears 5 miles from Baghdad
by dave1251
Yesterday at 10:34 PM
ML-The Silent Danger of Abrupt Lubricant Failure
by wemay
Yesterday at 10:15 PM
Apple releases important update
by Mystic
Yesterday at 09:56 PM
Machinery Lubrication - 'GrpIII syn is mktng term'
by wemay
Yesterday at 09:41 PM
The Paint is Peelin'!
by Nick1994
Yesterday at 09:39 PM
Pennzoil Syn Blend Or Yellow Bottle 5w30 ?
by crazyoildude
Yesterday at 09:29 PM
fram ultra, weird oil pressure
by bowhuuntr
Yesterday at 09:27 PM
Newest Members
PAssatGuy, mcn1970, KCChemist, bbuice, Hemingway
51460 Registered Users
Who's Online
25 registered (dmack2, 901Memphis, Duke, Falcon_LS, 6 invisible), 549 Guests and 162 Spiders online.
Key: Admin, Global Mod, Mod
Forum Stats
51460 Members
64 Forums
220062 Topics
3474881 Posts

Max Online: 2862 @ 07/07/14 03:10 PM
Donate to BITOG

Page 1 of 2 1 2 >
Topic Options
#463955 - 09/10/06 04:11 AM How much horsepower does it take to run a 10.6 1/4 mile?
55Test Offline


Registered: 09/22/04
Posts: 1828
Loc: New Brunswick
I went to a car show today. Lots of nice stuff there. There was a nice 98 Cavalier Z24 with a KILLER paint job, must have took weeks and weeks to airbrush the entire car! There was a Ferrari 328 GTS, a Hemi Cuda, A bunch of Triumphs and MG's, One Porsche 914, a few Shelby Z Daytona's and even a couple Chevettes! There was one car in particular we saw as we were about to leave. I think it was a 72-73 Dodge Demon set up as a 1/4 mile racer. He had it running before he drove it onto his trailer, oh lord what an awesome sounding motor! My dad was talking to this guy, he said the car runs a 10.60 in the 1/4 mile. That's pretty **** fast for a 340! I know there is a formula you can use to figure approximate horsepower from acceleration times, does anyone haappen to know it? I was guessing that car had 700-800 hp.

Top
#463956 - 09/10/06 04:26 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Thermactor Offline


Registered: 10/05/05
Posts: 291
Loc: San Diego, CA
it depends on curb weight, aerodynamics, gearing, power curve, and so on. a sportbike can do it with let's say 200hp, but a bus would need 10,000hp to do it.

Top
#463957 - 09/10/06 04:30 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
55Test Offline


Registered: 09/22/04
Posts: 1828
Loc: New Brunswick
I'm guessing curb weight on the Demon would probably be around 3100 lbs, and they weren't too aerodynamic either.

Top
#463958 - 09/10/06 05:12 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Dan4510 Offline


Registered: 05/19/03
Posts: 2363
Loc: Texas
About 550hp at the rear wheels if you can get it hooked up. Demon should do fine if you can get wide enough tires under it. A 340 in that car was not far away from 13s in stock form.

Dan

Top
#463959 - 09/10/06 05:14 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Brett Miller Offline


Registered: 09/09/03
Posts: 2636
Loc: Arizona
That must have been a pretty wild 340....

Top
#463960 - 09/10/06 05:18 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Dan4510 Offline


Registered: 05/19/03
Posts: 2363
Loc: Texas
Bone stock a demon with a 340 would run mid 14s. Tune the distributor curve and put a set of headers on it and you were in the 13s with hooking up problems due to small fenders.

I have a 340 in a 1978 volare 4 door built to stock specs with worked over heads and only 9.1 to 1 compression and according to the computer program with its weight and gears, it should be close to high 13s when i run it. 340 is a heck of an engine and you can make gobs of torque and hp with little effort. You dont even have to turn it over 6000rpm and a wing is not necessary either.

Dan

Top
#463961 - 09/10/06 05:46 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Drew99GT Offline


Registered: 10/11/02
Posts: 20692
Loc: Colorado Springs
Demons are pretty light. If it's set up for drag racing with slicks and a drag racing suspension and trans, mid 400s rwhp (through a drag racing automatic, that's a TON of power - WAY WAY over 500 on motor). Trap speed is a better indicator of hp. Fox Body Mustangs regularly run 10s with way under 400 rwhp. Transmission, suspension and tires [Burnout]

Top
#463962 - 09/11/06 02:39 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
obbop Offline


Registered: 06/24/04
Posts: 2832
Loc: MO
Was it 1968 or 1969 when Mopar sold from the factory a Dart with a Hemi in it. Not approved for street driving, sold for track use only but in those days you could get by with it on the street as long as the headlights, turn signals, brake lights, etc. were made operational.

One of the car magazines back then tested it on the track and got it down into the 10 second 1/4 mile range.

The Hemi had a rated 425 hp but some say it was more.

That special Dart was light weight, heater omitted, no back seat and other things to keep the weight down.

Boost the horsepower and reduce weight, the double whammy makes you go fast.

Still, getting into the 10 second range for the average guy can be tough and/or expensive.

As mentioned, yah' gotta' get those tires to hook up.

Those 340 engines were designed from the get-go to compete with the competition; Ford and GM. What were they rated at? 275 hp? Some auto writers have said they believe that figure was purposefully understated to keep the insurance companies happy.

There are some really good articles out and about on the Web about the 340 and the cars they came in.

Mopars are expensive to "hot rod," especially when compared to Chevy/GM. Parts costs are higher and there is less stuff available in the aftermarket. Still, someone who knows what they are doing in regards to reducing weight, maximizing power and traction between driven wheel and the pavement and who have a few extra bucks can make a fast machine.

Always did like the Duster/Demon 340 cars. A "poor mans" street machine though they have followed the price curve of steadily rising prices. It's incredible what some of the used muscle cars are going for.

Sniff......

I still sob nearly nightly for passing on the Superbird for $1,800 and the 1971 'Cuda convertible, 440 6-pack four speed in perfect condition for $2,600 or so (was it $2,800?) back in 1974. No place to park them since I was living aboard a warship.

Sigh.........

They coulda' been mine. ALL MINE!!!!!!!!!

Vrooooooom!!!!!!!!!!!

Top
#463963 - 09/11/06 03:10 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Drew99GT Offline


Registered: 10/11/02
Posts: 20692
Loc: Colorado Springs
Mopars are the bomb though. They have super duper beefy blocks and very tall deck heights, so if you stroke the **** out of them, you can run long connecting rods and keep the rod/stroke ratio great. Plus, dry intake manifolds (eat your heart out GM [Razz] )

Top
#463964 - 09/11/06 04:09 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
mechtech2 Offline


Registered: 09/05/06
Posts: 19479
Loc: Chicago Area
For a rough estimate, the internet has many free downloadable calculators for this sort of thing.
10.6 is very doable in that little Dart.

Top
#463965 - 09/11/06 04:22 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Al Offline


Registered: 06/08/02
Posts: 13581
Loc: Elizabethtown, Pa
Just for grins..lets say a 2800 lb car with 150 whp can do the quarter in 14 sec. And (this is a wild guess)30 hp goes into wind resistance. Hp will be a vunction of 1/ time ^ 3. So it takes 120 whp just for the acceleration.
120 x 14^3 / 10.6^3 +30=
120 x 2.3 +30 = 306

add another 30 HP for higher drag speed and another 25 for margin of error and you have 350 WHP. Thats probably too low bc of loss of friction (HP) due to spinning tires. [Smile]

Top
#463966 - 09/11/06 04:38 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
55Test Offline


Registered: 09/22/04
Posts: 1828
Loc: New Brunswick
quote:
Originally posted by obbop:


The Hemi had a rated 425 hp but some say it was more.


I read in some magazine that Big Daddy Don Garlits said himself that every 426 Hemi that came out of the factory dynoed at the very least 500 hp, and probably a bit more than that. Yeah, the 340 only made 275 hp, what a lie! Even the GT500 was way underrated, werent' they rated at something like 425hp as well? They were also known to dyno at around 500 hp or so.

Top
#463967 - 09/11/06 08:02 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Dan4510 Offline


Registered: 05/19/03
Posts: 2363
Loc: Texas
For example my old 1965 belvedere ran 14.00 in the quarter when i had my 340 in it. I weighted the car and with me in it with 1/2 tank of gas it was 3820lbs total.

Engine was not built special at all, just what I call a endurance build and was using stock 6 pack exhaust manifolds. Only big difference was comp cam that had more duration and lift @ .050 but same 268-276 total duration as auto six pack cam.

Computer program figured 285 rwhp to turn that time. So figuring 25% loss of drive train was making 380hp at the flywheel. And that was with the small 1.88 intake valve heads, so think of how much hp one could make with better heads, single plane intake, and headers. You could easily bump up to 500hp at flywheel with just those modifications.

The hemi was grossly underrated too. Not hard to go to 600hp with minimal modification.

I have an old mopar mag somewhere around here that did just taht, did a dyno run to see what a hemi actually made, i will see if i can find it and post results. Remember though, that hemi 425hp was net hp, after driveline loss and other losses were figured in, 425 was what the rear wheels should be seeing. with 25% loss thats 566 at the flywheel bone stock.

Dan

Top
#463968 - 09/11/06 11:24 AM Re: How much horsepower does it take to run a 10.6 1/4 mile?
Dan4510 Offline


Registered: 05/19/03
Posts: 2363
Loc: Texas
Found my old computer program, Quarter Jr.

Put in a demon with weight of 3200 lbs, 3.91 gears.

takes 550 hp at rear wheels to do a 10.67 quarter, mph varies by tire height and gear ratio. Mid 130 mph though.

Shifing at 6800 rpm with peak power at 6200 rpm with a 3000 stall converter. Higher stall converter makes it go slower by the computer numbers.

Dan

Top
#2232165 - 04/14/11 01:35 PM Re: How much horsepower does it take to run a 10.6 1/4 mile? [Re: 55Test]
morris Offline


Registered: 08/24/08
Posts: 3681
Loc: ks, wichita
to:obbop the car you are talking about is the Hemi cudas and Hemi darts. 1968 models. of course ronnie sox got one. i talked to him in 1968, he said it will run 10.8- 10.50, that was 1968. in 2010 they run 8.6. nhra lets you build one from a reg cuda, as the value of organals are about $500,000. the organals had a title from Hawaii so they wouldnt have to have a heater. in 1968 in tulsa the ford and chevy guys was complaining that they couldnt keep up. nhra told them "its the same rules for everyone" "if you car maker cant make a fast car thats not my trouble". so nhra made a class that is for hemi-cudas ONLY. i didnt like hearing all that crying.

Top
Page 1 of 2 1 2 >