The Hot Lap system consists of three units:
Transmitter (Model HL623 or HL628) An infrared flashlight that stands at the side of the track and shines a beam across the track for the entire race.
Receiver (Model HL611 or HL614) A small metal box that mounts in the car, tie wrapped to the roll bar or other location in plain view of the transmitter. It faces the direction of the transmitter.
Display (Model HL615 or HL618) A box with a large digital readout that mounts in the car in front of the driver and shows two digits of lap number and five digits of lap time. It refreshes at the end of each lap and displays for the entire lap. It connects to the receiver with a telephone-type cable (supplied).
The transmitter shines a coded beam across the track. The code prevents the system from being fooled by stray flashes of light such as strobe lights. The beam is cone-shaped and fans out at 15-degrees each side of center, becoming 40 feet in diameter at a 60-foot range. The receiver in the car needs to see the beam for 0.002 seconds to recognize it as a valid signal. Two transmitter types are available:
Extended Range Transmitter (Model HL623) With 60-foot range. The beam diameter at 60 feet is 40 foot. The HL623 is powered by four AA batteries that last for about 20 hours.
Double Range with 12 Volt Battery Leads (Model HL628) With 120-foot range. A 5-foot cord with battery clips to attach to a 12-volt car or motorcycle battery, which will power the transmitter for many days before recharging is needed. It is turned off by unclipping the leads from the battery.
You can mount the transmitter on a camera tripod, use our pit wall tripod (Model HL99), or you can tape it to the pit wall or a light pole. The tripod is not furnished with the system. Tightly mount the transmitter so it doesn't wobble. Do not move the transmitter once the race starts since accuracy depends on the beam being in the same place every time the car passes.
Put the transmitter 10 to 15 feet off track side in a location where the cars will be running single file. Aim the transmitter across the track. If you mount the transmitter on a high mount like a light pole, aim it down at the car and aim the receiver up at the transmitter. Remember that the receiver in the car must see the transmitter, so give the beam a clear shot. The car must spend 0.002 seconds in the beam for the receiver to see it. A car moving at 200 MPH must be in the beam for 2-1/2 feet to trigger the display.
Put only one transmitter on the track to get lap times. All cars will share it. More than one transmitter will give segment times. If you must have a backup transmitter, separate the two by 5 to 10 feet so their beams do not overlap.
Hot Lap receivers recognize only Hot Lap transmitters. They do not trigger on flash bulbs, strobes, reflections or other transmitter brands.
Glass reflects infrared and shortens range. Avoid mounting the receiver behind windows.
Infrared will go through some materials such as plastic or fiberglass, but range will be shortened and it should be avoided. Infrared will not go through metal, concrete or rubber.
Transmitter light conflicts. The transmitter throws its beam in a 30-degree arc (15-degrees on each side of center). If two Hot Lap transmitters are located in the same place, the beams can mix, confuse the receiver, and cancel the signal.
Sunlight has infrared in it, which shortens the range of the system. Do not put the transmitter where the receiver must look directly into the sun because this can blind the receiver temporarily.
Avoid aiming the transmitter directly at walls or signs. The beam can bounce off the wall and back into the receiver giving it a false reading.
Rain shortens the range of infrared light - just like a flashlight.
Flying dirt, as found in off-road racing, can shorten the range of the beam.
Hot exhaust pipes radiate infrared. Do not aim the receiver over them.
The transmitter is battery operated. Batteries are not furnished with the system. Four AA batteries must be installed inside the Model HL623 transmitter. A switch on the back of the tube turns on the infrared beam. Since you cannot see infrared, an LED shows when the beam is on. Turn the transmitter off when not in use to save the batteries. You will probably leave the transmitter in place all day, so make sure the batteries are fresh.
To install AA batteries: Unscrew the front cap of the transmitter and pull out the plastic retaining ring and circuit board. The batteries are mounted on this board and their polarity is marked. Average battery life is 20 hours.
Batteries are the biggest source of systems problems. Weak batteries reduce range. Replace all four batteries with fresh alkalines before each race if that is what it takes to be sure of their performance. Use only brand name alkaline batteries. Non-alkalines will not last. Do not use rechargeable batteries. They do not produce enough power to run the transmitter. Fresh AA cells produce 1-1/2 volts each, so four together make 6 volts. When voltage drops below 5 volts, range drops below spec. Battery wear-down depends on heat, their make, and their age.
Receiver (Model HL611 or HL614) A small aluminum box with a red (or clear) window on one end. It comes with a V-block attachment point to tie wrap to the roll bar or other vehicle location. The HL611 receiver has provisions to mount a 9 volt battery inside and is used with a HL618 small outline display. In this case a power switch is located on the receiver to control system power. When using a HL615 standard outline display, the battery is located in the display. In this case, a HL614 receiver is used and there is no power switch on the receiver.
Tie wrap the receiver to the roll bar in the car or mount it in any other location with the red (or clear) window facing in the direction of the transmitter. Aim the receiver directly at the transmitter. If you must mount the receiver behind a panel, mount it close to the surface and cut a 1-inch hole in the material. The infrared sensor is located 3/8 inch behind the red (or clear) window. More than 15 degrees of tilt or swing can shade the sensor from the transmitter beam. Test your mounting location using the Cal (P2) feature as described on the next page.
The receiver just sits in the car and waits to see the beam. When it sees the beam for 0.002 seconds, it tells the display to increase the lap count by one and show the time elapsed since it last saw the beam. The receiver sends information to the display over a telephone cable.
Two styles of display are available:
Standard Display (Model HL615) A black plastic box with a 9-volt battery in it that runs both the display and the receiver. It will operate for approximately 40 hours before replacement is required. A phone jack on the module attaches to the receiver.
Small Outline Display (Model HL618) A smaller display for formula cars, go karts, motorcycles and other racing vehicles with limited space in the driver's area. The LCD size is the same as the standard display. In systems with this display, the battery is moved to the Model HL611 receiver.
Mount the display in view of the driver. It can be held on the dash with Velcro, or can be screwed or clamped to a bracket. A 9-volt battery normally operates the display. Use only brand name alkaline batteries. On HL615 displays, the battery is accessible through a door in the back if the unit, so mount it in such a manner that the battery can be changed.
System parts connect together with a telephone-type cable supplied with the system. This cable plugs into the bottom of the display and connects to the receiver. This type of cable is available at stores that sell telephones. If your cable gets damaged, or if you want to use a longer or shorter one, it can be replaced with another four- or six-conductor telephone cord have RJ-11 connectors and identical internal wiring. Cables are available from I/O Port Racing Supplies.
Please read this if you supply your own cable. There is no standard for phone cable wiring. Before you buy a cable, hold the two connectors side by side, plastic clip toward you, and look at the color of the wires. The color sequence must be the same on both ends; for example, black-red-green-yellow. If the colors are reversed from one end to the other, reject the cable. The system will not work with reversed wires. It shorts out the 9-volt battery and makes the display show 5-second laps over and over.
A switch on the HL615 Standard Outline Display turns it and the receiver on and off. When the system includes a HL618 Small Outline Display, this switch is on the HL611 receiver. Turn the unit on in the pits before an event to make sure it is operational.
Two pushbuttons on the display, labeled START and MODE, have four functions.
These functions are described as follows:
To review recorded lap times (P1). Press the MODE button for 2 seconds. P1 appears in the left two digits. Press and release the START button to display lap 01 and its time. Lap 01 replaces P1, and it blinks to indicate the system is reviewing. Press and release START to advance to lap 02, etc. When START is pressed on the last recorded lap, the display returns to lap 01. Hold START down to quickly sequence through all recorded laps. To cancel review mode and return to normal operation, press MODE.
To calibrate to the beam (P2). The Cal mode allows you to verify alignment of the transmitter and receiver. To select, press MODE for 2 seconds. P1 appears in the display. Release MODE and press it again quickly. P2 replaces P1 in the display. Now press START and CAL ---- appears. Aim the transmitter at the receiver and a 0 appears after the last dash. As long as the 0 is there, the receiver sees the transmitter. To return to normal operation, press MODE.
To display a free running stopwatch. While driving, press START after the first lap signal has been received from the infrared transmitter or the steering wheel switch to see a free running stopwatch display of lap time. The next lap signal returns the display to its normal state.
To clear the display and memory. Hold down both START and MODE for 2 seconds. The display clears all lap memory and starts recording the lap times after the first lap signal has been received. It is a good practice to clear the unit on pre-grid just before the start of a race.
When the display unit is first cleared, it shows all dashes (-------) until the first lap signal is received. When the car cuts the beam, the display changes to all zeros (00 00000). This normally would be shown on the pace lap. After the second lap signal is received, and from then on, the display shows the number and time for the lap just completed.
Model HL611 receiver do not require calibration. Model HL614 receivers are calibrated at the factory and you will probably never need to re-calibrate. However, if range falls off or you want to assure peak performance, set the system to Cal (P2) mode as above and perform the following:
Editor's note: the factory may have missed a step here.
Transmitter: (Model HL623) Material: Water resistant plastic tube. Size: 2-1/4" in diameter and 9" long. Weight: 12 oz. including 4 AA cells. Equipped with mounting V-block tapped for 1/4-20 threads as on a tripod.
Receiver: (Models HL611 and HL614) Material: Aluminum. Size: 4-3/8" W x 2-1/2" H x 1-1/4" D. Weight: 6-oz. Mounting: V-block attach point for cable tie. Views through one end.
Standard Display: (Model HL615) Material: black plastic. Size: 5-1/2" W x 3-1/4" H x 1-1/2" D. Weight: 9-oz. including 9-volt battery.
Small Outline Display: (Model HL618) Material: Aluminum. Size: 4-3/8" W x 2-1/2" H x 1-1/4" D. Weight: 6-oz. This display requires the use of a HL611 receiver.
System Accuracy: 0.002 seconds.
Memory: 60 laps; then accepts no more data until cleared.
Lap Times: Minimum 5 seconds, Maximum 5 minutes.
Longacre warrants the Hot Lap system against defects in materials and workmanship for a period of one year from the date of purchase. During this period, Longacre will repair or replace, at Longacre's discretion, any Hot Lap system or component returned prepaid by the original purchaser, providing it has been determined by Longacre that the unit failed due to defective materials or workmanship.
This warranty excludes the following: 1) Normal wear and tear. 2) Removal or replacement costs. 3)Damage to related components. 4) Cost incurred due to vehicle down time. 5) Shipping costs. 6) Failure due to misuse, abuse, improper installation, and/or unauthorized repairs or modifications, at the sole discretion of Longacre.
Implied warranty - This warranty is in lieu of all other and/or representation, express or implied, including without limitations, warranties of merchantability and fitness for purpose, and all other liabilities including special consequential damages in connection with the sale or use of any Longacre product.