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    1. #1
      Join Date
      Dec 2010
      Location
      Fredericksburg, VA.
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      3,125
      Country Flag: United States

      HP required to go 100mph?

      I'm wondering how much power is required to cruse a 1st Gen Camaro at 100mph in a typical open road challenge. I know it is probably a calculation based on vehicle frontage area. Does anyone know of HPvsSpeed calculator and also what the frontage area of a 1st Gen Camaro is?

      Steve Hayes
      "Dust Off"
      68 Camaro

      Speed has never killed anyone. Suddenly becoming stationary, that's what gets you!
      "Jeremy Clarkson"


    2. #2
      Join Date
      Apr 2011
      Location
      San Diego
      Posts
      128
      I'm thinkin the only upgrade you'll need for that is steel toe boots lol

    3. #3
      Join Date
      Jun 2011
      Location
      St. George, Utah
      Posts
      1,629
      Country Flag: United States
      I had an 84 Chevette that could hit 105 and could maintain 100 fairly easily. It came from the factory with 79 hp, had 3.36 gears and a 3 speed auto. Mods were it was lowered 3" and had a high flow exhaust. Everything else was stock. If your car can't hit 100 mph you should trade it in on a Prius. ;)




      Are you sure you didn't mean 200?
      -Ben, Your friendly neighborhood Rendering dude

      SRD on Facebook

      79 Cutlass wagon build


    4. #4
      Join Date
      Jul 2005
      Location
      Portland, OR
      Posts
      126
      Country Flag: United States
      Try http://www.wallaceracing.com/Calcula...or%20Speed.php.
      and try downloading the original GM vehicle info kit for your car from http://www.gmheritagecenter.com/gm-h...tion-kits.html to find the height and width.

      Kevin
      Last edited by 4mul8ion; 01-09-2013 at 08:18 PM. Reason: added link

    5. #5
      Join Date
      Sep 2002
      Location
      So. Cal
      Posts
      1,179
      I think I've seen some of the equation in the past somewhere but forgot where. Cf drag, drivetrain losses, Rolling resistance, etc..

      I have used this dos program many years ago that was cool. This might help get your answer. Looks like it will run in java now.

      http://www.cartestsoftware.com/cartest4.5/
      Ron DeRaad
      68 Camaro RSx
      Darton Sleeved LS9 - 434ci (4.155x4.00)
      AFR LSX245 Heads (12:1cr)
      660hp/588tq

    6. #6
      Join Date
      Apr 2001
      Location
      Central CA USA
      Posts
      6,093
      Country Flag: United States
      The book "Camaro Exposed" by Zazarine lists a 1967 Camaro frontal area of 20.6 Square Feet
      A coast down test would give you a better idea of actual drag. Remember, there is Aero drag and Rolling drag. Rolling drag does not increase with speed like Aero drag, but it does go up a little.

      Most any Camaro will be able to go 100 unless it's up a darn steep hill.
      I'd look at what RPM's you would be turning for your rear axle ratio and can your engine do that for 90 miles in the case of the Silver State - without puking oil or other issues.
      David
      Last edited by David Pozzi; 01-09-2013 at 10:26 PM.
      67 Camaro RS that will be faster than anything Mary owns.

    7. #7
      Join Date
      Aug 2011
      Location
      Sevierville, TN
      Posts
      524
      Country Flag: United States
      David is right. the questiion shouldn't be how much horsepower you need, it's what gear ratio and trans setup to run.

      For example, my 68 C10(frontal area of a brick wall) would easily hit 100mph with a stock 350/TH350 with a 3.73 gear ratioand a 28" tire, but I was turning just over 5000rpm. I later switched to a 3.07 gear and a 29" rear tire and I could run 100mph at around 3800+/- rpm. At that rpm, the engine was still churning pretty good, but was alot more comfortable than at 5K.

      The ideal setup would be with an manual overdrive(6 speed recommended) transmission with a modest 3.55-3.23 r&p gear set. Even any decently built sbc(approx. 300-350hp) would be happy with that setup. A Gen 3/4 LS engine would also be happy doing those duties. If you go with LS, look into slightly larger than stock cam profiles, but nothing too radical so the torque curve still stays somewhat level throughout the power range.
      Matt Kenner

      68 C10 stepside

      If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

    8. #8
      Join Date
      Jun 2012
      Location
      South Lyon, MI
      Posts
      1,171
      Country Flag: United States
      My 74 Nova with the stock 350/140 horsepower motor, TH350 and 308 gears would barely break 90 mph back in the day before I woke it up with some needed mods.

      My 74 Vega with the stock 140 CID/85 horsepower motor and some aerodynamic mods would hit 110 to 115 on a good day.

      My guess would be somewhere near 130 to 150 crank horsepower would get you to 100 mph if you are patient enough.

      I don't believe you will be able to compete in the 100 mph class unless you have more than double the needed cruising power. Remember, you have to get there and go up hill too. If I wanted to cruise along in the 100 mph class, I would shoot for no less than 300 crank horsepower so I could get to speed in a reasonable time and could hold that speed going uphill without taxing the motor.

    9. #9
      Join Date
      Dec 2010
      Location
      Fredericksburg, VA.
      Posts
      3,125
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      At this point this is a mental excersice with an eye to running the Silver State Classic in the future. I currently have a healthy 1st Gen 350, T-10, 3.50 rear, 26" tires. At 60mph I'm turning 2700rpm. This is a very comfortable long range crusing rpm and the engine is well into it's power range. If I were to add a couple of OD gears I think this would easily cruse 100 for extended distance.
      Steve Hayes
      "Dust Off"
      68 Camaro

      Speed has never killed anyone. Suddenly becoming stationary, that's what gets you!
      "Jeremy Clarkson"

    10. #10
      Join Date
      Aug 2011
      Location
      Sevierville, TN
      Posts
      524
      Country Flag: United States
      Sho Nuff!!
      Matt Kenner

      68 C10 stepside

      If you can leave two black stripes from the exit of one corner to the braking zone of the next, you have enough horsepower. - Mark Donohue

    11. #11
      Join Date
      Sep 2002
      Location
      So. Cal
      Posts
      1,179
      Not sure how accurate the Cartest program is, but I come up with approx 50hp/50tq to push a 3600lb car with the 20.6 frontal area, 3.50 gears, 26" tires (335/30/18), 4th gear 1:1. With a .63 OD, 80hp/80tq required.

      Makes sense since the engine needs to work harder to turn OD ratios.
      Ron DeRaad
      68 Camaro RSx
      Darton Sleeved LS9 - 434ci (4.155x4.00)
      AFR LSX245 Heads (12:1cr)
      660hp/588tq

    12. #12
      Join Date
      Apr 2001
      Location
      Central CA USA
      Posts
      6,093
      Country Flag: United States
      Remember it's a standing start, so you will need to drive at something like 120 for a while to average 100 for the course.
      67 Camaro RS that will be faster than anything Mary owns.

    13. #13
      Join Date
      Jul 2010
      Location
      Sacramento, CA
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      1,224
      Country Flag: United States
      I have a ticket for 100mph in my old 65hp truck. My camaro with 2.42:1 rear gears does a hundred at about 3200rpm.
      -James

      1974 Z28 SCCA C Prepared
      1990 Firebird NASA CMC
      2005 Mustang GT SCCA F-Street (new for 2015)
      1989 Civic Si SCCA STC

    14. #14
      Join Date
      Jun 2012
      Location
      South Lyon, MI
      Posts
      1,171
      Country Flag: United States
      Open road racing is cool. It is one of my goals to run one of the open road races when I get my car done and dialed in.

      From what I have found, heat is your biggest enemy. Without coolers your engine oil can get hot enough to melt the nylon drain plug gasket.

      I would recommend good engine, trans, powersteering and diff coolers. My 1988 BMW 325is had a lot of cooling from the factory to handle the autobahn it was bred for. US highways did not pose a challenge.

      The other issue is proper tire pressure. They heat up as you go and cause the pressure to rise.

      100 mph is easy for 10 or 15 minutes. But for an hour it is another story.

    15. #15
      Join Date
      Jan 2013
      Posts
      4
      Country Flag: United States
      Quote Originally Posted by formula350 View Post
      I'm thinkin the only upgrade you'll need for that is steel toe boots lol
      steel toe boots lol is the only thing he needs for?