JANE will be holding a Dyno Day at KTR Motorsports in Ayer, MA on Saturday, April 28th, starting at 9:00am.  You can either sign up to have your car dyno'd, or just show up as a spectator to observe the action and drool over the many sports , vintage street, and race cars that KTR maintains.

If you'd like to dyno your car, PLEASE CONTACT STU FORER ASAP BECAUSE IT IS FIRST COME, FIRST SERVED!  We can accommodate 15 cars for dyno testing, which includes three dyno runs per car.  Go to KTR's web site or see the FAQs below for more information on the dyno and some examples of dyno graphs.  The dyno at KTR also measures the stoichiometric (air-to-fuel) ratio over the entire RPM range.  The correct ratio, neither too rich nor too lean, will improve drivability.  It will also ensure that you do no engine damage.  Running too lean can cause burnt valves and overheating; running too rich can cause fouled plugs and poor gas mileage.  You'll get a graph of power and torque versus RPM.  Stu's XK120, which had its engine built by noted Jaguar race engine builder Tivvy Shenton, was too lean.  At the last dyno session, they had both Tivvy's and Stu's cars dyno'd by KTR, and repaired a lean condition in each of them.

If you're coming as a spectator, PLEASE CONTACT STU FORER BEFORE APRIL 14TH SO WE CAN GIVE KTR A HEAD COUNT!  There are many things to see at KTR.  It has a 32,000 square foot building, which is huge for an automotive service facility.  KTR is owned by Bob Jett, who was a principal and founder of Cambridge Technologies, a large software company.  Bob is a vintage racer and a car and motorcycle collector.  He bought the business from John (Jay) Geils of the Jay Geils Band.  Although Jay is and was a successful performer, he is also a mechanical engineer who raced a vintage Ferrari TdF Berlinetta.   There are numerous rare cars being restored, race-prepared, and serviced at the facility.  KTR is also a distributor and assembler of the Noble M400 high-performance sports car.  Click here for a taste of KTR from the event report of last year's event.

KTR has two divisions: KTR Performance, which modifies and tunes street high-performance and late-model racing cars for more horsepower and better handling; and KTR Motorsports, which restores, race-prepares, repairs, stores, and provides trackside assistance to imported, classic, and vintage racing cars.  If you've attended vintage sports car events throughout the Northeast, you've surely spotted KTR vehicles, trailers, and cars sporting KTR logos.

The cost to dyno your car will be: $75.00 with an $8.00 refunded if we get 15 cars.  Spectators who do not come with a car to be dynoed will be asked to contribute $5.00. Refreshments  are included at no charge.

KTR Performance  (Map)
99 Fitchburg Rd.
Ayer, Massachusetts 01432
Tel:  978-772-9911
 Email: info@ktrperformance.com

Stu Forer, Event Coordinator can be reached at:
160 Medford Street
Warwick, RI 02889-6432
Email: dbmkiii@hotmail.com
Phone: 401-739-4171

See you there!

Frequently Asked Questions About Dynamometer Measurement

FAQ: Why should I dyno my car?
Testing your car on a dyno can tell you a lot about your car's performance and state of tune. On the KTR dyno you will receive not only a complete power and torque curve to compare with similar engines, but also a air/fuel curve showing the air/fuel mix across the RPM range. This can help point out areas of rich mixture that are costing you fuel and power, but also areas of lean mixture that can translate directly into costly engine damage such as burned valves and pistons.

FAQ: What do I need to do before I arrive at my dyno tuning appointment?
To ensure that you get the most out of your dyno tuning session there are a few key items to remember.

  • Fuel: Your vehicle will consume a healthy amount of gasoline during the tuning process. Be sure to arrive with a full tank of gas.
  • General Maintenance: To make certain that you get the most out of your dyno experience it is imperative that you have kept up on your routine scheduled services. You can't expect your vehicle to operate at it's peak if parts are worn out. For example, ensure that you have fresh spark plugs and a clean air filter. Safety is also a concern while your vehicle is at KTR. If KTR determines that a worn tire, tie rod end or other mechanical problem puts the safety of a KTR employee or spectator at risk, KTR will postpone your dyno session until these issues are resolved.
  • Realistic Goals: Email or bring with you a list of your modifications and expectations. This information will allow the dyno session to run more efficiently and effectively for everyone involved. Having your vehicle "tuned" on a chassis dyno, can be a great experience.

Is photography and video taping allowed while my car is on the dyno?
Yes. If you would like video or still pictures taken, we are more than happy to oblige.

How is engine power measured?
The fact is there is no way of directly measuring power -- all types of dynamometer measure torque and then power is calculated from the formula BHP = Torque (ft/lbs) x rpm/5252. This basic equation is the foundation of all engine design, development, and tuning. Two main methods of measuring power are used in the automotive industry -- (1) measurement at the crankshaft of the engine or (2) measurement at the driving wheels. Read on to find out more about these two methods.

How does an inertia type rolling road work?
The majority of rolling roads used to determine power figures in the US are inertia dynamometers. Inertia dynos do not directly measure the force on the dyno rollers to determine power figures. Instead, these systems calculate the force on the rollers using the formula:
    F = ma
where F is force; m is mass; a is acceleration.

The mass and system inertia of the dyno rollers is known. In order to calculate the force applied, inertia dynos measure acceleration of the rollers by measuring the increase in current and voltage production when the dyno's eddy-current retarders are used as a power generator instead of a power absorber (as used to hold the dyno load when mapping engines). Force on the rollers is therefore the roller mass multiplied by the acceleration determined by the voltage output. This force is multiplied by the radius of the roller itself to give torque at the wheels using the following equation:
    T = Fr
Where T is torque; F is force; r is radius of application.

Power is determined by using the formula:
    BHP = Torque (ft/lbs) x RPM/5252
This calculation is then used for the power at the wheels measurement.

If an ignition pickup on the engine is used, these power figures can be used to plot a power curve. In order to determine power at the flywheel figures, a coast down procedure is used. This procedure measures the deceleration of the rollers, and uses this figure as negative acceleration and the F=ma calculation is used again to obtain the power losses through the transmission.

The major problems with these systems occur when changes are made to any of the rotating masses in the system. This includes items such as the clutch, flywheel, or aftermarket wheels. These items do not change the power of the engine (obviously). However they will change the rate of acceleration of the vehicle. Therefore these changes will change the power output measured on an inertia dyno. This is another reason why a number of dyno manufacturers will not guarantee greater accuracy than 5% for their dyno systems.