Frequently asked Questions
The following are the most frequently asked questions about our products. If you have a question regarding one of our products that is not covered here, please fill out the form below and press “Submit”. One of our team members will answer your question shortly. If your question gets chosen by our team, then it will be featured on this page!
A: The DUI is not like the multi-spark systems that utilize an external capacitive discharge ignition box. The DUI is a one-piece ignition system with no external components. The DUI incorporates a high dwell module inside the distributor that increases the coil saturation time. The longer saturation time makes the coil produce one long duration spark as compared to several multiple sparks. The longer duration spark will improve throttle response and low end power. In conjunction with our 50,000-volt coil, spark plug gaps can be opened up to .055″. Most spark box systems recommend a gap of no larger than .045″. The DUI’s coil and module only draw 2-3 amps. Most spark box ignitions draw anywhere from 6-10 amps. The lower amperage draw of the DUI allows it to run cooler, making it more reliable than the spark box. The less amperage draw is very important if you are a racer that just runs a 12-volt battery with no alternator. Most importantly, the DUI distributor is custom tuned on a distributor machine for your vehicle and engine. Custom tuning insures maximum performance and eliminates detonation. This is a service that the other ignition companies do not provide. Instead, they’ll send you a curve kit so that you, the customer, can figure out your own advance curve.
A: No particular terminal on the DUI is designated as number 1. When you bring your number one cylinder up to top dead center on the compression stroke, you can drop the distributor in and point the rotor toward any terminal that you want to make number one. Once you establish which terminal on the cap is number one, follow your firing order from that point.
A: Mechanical advance is the centrifugal weight and spring assembly located underneath the rotor that provides the largest part of the timing curve. The vacuum advance canister, located on the side of the distributor, provides additional timing only when the engine is pulling vacuum. The mechanical advance along with the initial advance (base timing set at idle) is what gives you total timing. An example of total timing would be 12° initial plus 24° of mechanical which equals to 36° total. Vacuum advance is not figured into total timing because it will only function when the engine is not under a load. Example: If your vehicle is cruising on a flat stretch of road or going downhill, vacuum advance will come in and add as much as 15° to the total timing for increased fuel mileage and cleaner spark plugs. It is not uncommon to see as much as 50° – 52° of timing with vacuum advance. But don’t be alarmed by this being too much timing as the vacuum advance will decrease once you accelerate and put the engine under a load. Under hard acceleration the timing will go back to the original total with no vacuum advance.
A: Always set your timing with the vacuum advance disconnected and the vacuum line must be plugged.
A: Your hot wire for the DUI must be at least 12 gauge and it can be connected to the starter solenoid or a fuse. The solenoid is usually the easiest place to connect your hot wire to but make sure you use the terminal that is hot only when the key switch is in the start and run position. Same with using a fuse, just make sure the voltage is present only in the start and run position. In most applications, we do not recommend using the existing ignition hot wire. It may be too small or a resisted wire thus reducing the voltage. 1974 and later GM vehicles can use the existing hot wire with the DUI as they were originally set up for HEI distributors.
A: The DUI Distributor cap is exactly the same dimensions as a GM HEI cap which measures 5 1/4″ in diameter where it attaches to the distributor housing. Overall it is about 1 1/2″ larger than most stock and points style distributor caps.
A: We need information about the vehicle and engine such as cam duration & lift, compression ratio, carburetor size, vehicle weight, towing weight (if applicable), maximum rpm, transmission and octane of fuel. If you have a supercharger, we need to know the maximum amount of boost it produces. Also, if you run a nitrous kit, we need the horsepower rating for the system you are running.
A: In most applications, we recommend using Autolite Platinum Spark Plugs. These plugs have worked very well with our Distributors and Firepower Ignition Kits. You should retain the same heat range your engine calls for but open the spark plug gaps to the recommended setting as set forth by the distributor or ignition kit instructions. CAUTION! If you are running Nitrous on your engine, DO NOT use the Platinum plugs. Use a standard type spark plug as the nitrous will destroy the platinum tips.
A: It is hard to say exactly how much the DUI will increase horsepower. Too many parameters are involved to answer this question with an exact answer. On average, the DUI will produce an increase of 15-20 horsepower over a stock ignition system. Your engine may see more or less depending on other modifications. The DUI has been dyno tested to provide 40 more horsepower over a stock GM HEI! Unfortunately, we cannot guarantee this type of result for everyone. But in most every case, the DUI will provide a noticeable increase in performance and fuel mileage.
A: We do not sell our curve kits separately because our specialty is tuning the weights and springs on a distributor machine for the customer’s application. This provides a more accurate timing curve and eliminates the guess work for the customer.
A: No. Stock GM HEI parts such as a module, coil, cap and rotor can be used on the top of the DUI distributor to replace a possible bad part. These can be found at any local auto parts store. The stock HEI parts will get your DUI running in case of a breakdown but they will not provide the same performance as the original DUI parts.
A: The LiveWires measure 300-350 ohms per foot resistance.
A: The Street/Strip DUI and Tri-Power Ignitions have a one-year warranty. All Racing versions have a 30 Day warranty. This warranty covers all parts and labor. No refunds are given after a product is installed. If a product is found to be defective after installation, we will honor the warranty.