jimsgarage

Building a Track Car – How much power?

With the suspension all set and the car corner balanced it was time for one more detail.  I needed to find out what the true power band was so that I could make the most of the Shift-I that I had gotten from Flyin’ Miata.

That meant a trip to Long Road Racing in Raleigh where they had a chassis dyno.  At Long Road they prepare many Miatas for the spec Miata class as well as GT racers and many people’s street cars.  I made an appointment and this morning I drove over for the dyno run.

Eric was there and set up the car on the rollers.

Then it was time to see just what this engine with over 152,000 miles on it had left for power.

Three pulls were done taking the car right up to red line.

The results were pretty impressive.  Horsepower peaked at 117 and torque was well over 100.  Keep in mind that these measurements were taken at the wheels.

 

So

now I could tell where my power and torque bands were and when I was waisting revs and when I was not.

Now I’ll have to find a track event.

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8 responses to “Building a Track Car – How much power?”

  1. Jason Schneider Avatar
    Jason Schneider

    Just curious – what were the HP & TQ numbers (from the factory) when new? Are your numbers standard for a Miata in the spec series?

    Reply
    1. jimsgarage Avatar
      jimsgarage

      Jason – I’m sorry to say that I don’t have answers to those good questions. Most of the hp tq numbers from the factory specs would be taken at the flywheel. I just don’t know what spec Miatas usually come in at.

      Jim

      Reply
  2. Chris Belcher Avatar
    Chris Belcher

    Jim,
    Thats a pretty decent dyno run for a car of that age. Very consistant. I know it doesn’t seem like much power but your torque curve is very flat with over 100 lb/ft from 3000-6000 RPM….what more can you ask for. Great Job.
    Chris

    Reply
    1. jimsgarage Avatar
      jimsgarage

      Thanks Chris. Yes, I agree, pretty decent for the miles. 🙂

      Reply
  3. Jay Avatar
    Jay

    SPECIFICATIONS
    1996 Mazda MX-5 Miata M Edition
    Base Price $ 24,760
    Engine Type dual overhead cam, 16-valve inline 4-cylinder
    Engine Size 1.8 liters / 110 cu. in.
    Horsepower 133 @ 6500 (likely at flywheel)
    Torque (lb-ft) 114 @ 5500 (likely at flywheel)
    Transmission 5-speed manual
    Wheelbase / Length 89.2 in. / 155.4 in.
    Curb Weight 2293 lbs.
    Pounds Per Horsepower 17.2
    Fuel Capacity 12.7 gal.
    Fuel Requirement unleaded regular
    Tires P195/50 R15 Bridgestone Potenza
    Brakes, front/rear antilock vented disc / disc
    Suspension, front/rear independent double wishbone, with coil
    springs / independent double wishbone
    with coil springs
    Drivetrain front engine, rear-wheel drive
    PERFORMANCE
    EPA Fuel Economy – miles per gallon
    city / highway / observed 23/29/25
    0 to 60 mph 8.7 sec
    1/4 mile (E.T.) 16.6 sec
    Coefficient of Drag (cd) 0.38, top up

    Reply
    1. jimsgarage Avatar
      jimsgarage

      Thanks Jay – you are the MAN.

      The current curb weight with all the added bracing, a hard top, and the carpeting removed along with the A/C and cruise control is 2382 pounds. It sounds like the horsepower figures are pretty darn close to what the dyno shows. I might have a HP or two gain with the more efficient air cleaner and long tube headers. In any case, pretty good power for an engine with all the miles it has on it.

      Reply
      1. Jay Avatar
        Jay

        You dumped the spare , correct?

      2. jimsgarage Avatar
        jimsgarage

        The weight I gave is with with the trunk empty and a full tank of gasoline with no one sitting in it. Since I didn’t budget a trailer and a tow vehicle I will pack the mini spare, jack, etc. until I get to the track.

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