On The Limit
No doubt there are many of you in the following predicament. After having invested much time and money in your prized MG, you wish to enjoy it to its fullest. Because we all take pride in our MG's, and enjoy using them for what they were designed, fun club activities. And bearing in mind the parts required to keep our beloved MG's on the road are increasing in scarcity and increasing in price as time goes by, I thought it timely to present the following information, having recently been through this dilemma myself.
The fitting of a Rev Limiter! In a bid to protect and preserve the thousands of dollars invested in the heart of my MG, because I, like many of you, enjoy club competition in my MG. I particularly enjoy passing later model MG's on the race track in my '64 Midget! And not wishing to over rev my recently rebuilt A-Series Motor and cause a big and expensive bang in my over exuberance to overtake an F at Sandown or the like, I thought it wise to protect my motor from over revving in the heat of the moment and invest in a Rev Limiter. So began the research and information gathering.
Up until a year or so ago an Aussie company (Speed Technology) used to make what the industry terms a "Soft Cut" Rev Limiter. What a "Soft Cut" Rev Limiter achieves is sequential spark stealing. Once the established RPM limit is reached, random spark stealing starts within one spark, reducing plug fouling common with repetitive stealing type limiters. This random spark stealing also helps protect the motor from any sudden drop in performance and the stresses this would have on the internals of the motor. A great way preserve and protect your MG's motor.
However, since the introduction of EFI the need for such a rev limiter in Australia has diminished, as EFI systems have their own limiter built in. Unfortunately due to the drop in demand and the increase in scale required to make a production run feasible, Speed Technology ceased the production of their "Soft Cut" Rev Limiter last year.
Why do I mention this I hear you ask? Well I believe that there is still a market for such a rev limiter, especially one which is suitable for cars retaining a points ignition set up, such as our beloved MG's! So undeterred I sought to find another alternative rev limiter and soon discovered a USA company Pertronix produced a 'Digital Rev Limiter' that was a "Soft Cut" type suitable for a points ignition.
After an exchange of emails with the USA, Pertronix put me in touch with their Aussie Distributor Pro-Quip International, located in Bayswater of all places (www.proquip.com.au). Gordon Ledwidge of Pro-Quip may be a name familiar to some of the racing guy's, being a CAMS Scrutineer. He also punts a Datsun SSS and has over 25 years competition experience to draw on.
Gordon was very helpful in answering all my questions and highlighting the Pros of adopting such a system. The Pertronix Digital Rev Limiter's small size (6.35cm x 7.62cm x 3.55cm) and simple 4 wire hook-up makes installation painless. There are easy to understand instructions included and Gordon is only a phone call away (03 9761 1110).
The Digital Rev Limiter is designed for use with any 4, 6 or 8 cylinder
engine 12 volt negative ground ignition systems using either points or
aftermarket inductive type ignition systems, including the Pro-Quip's
popular Ignitor® and Ignitor® II points replacement systems for
A & B Series MG Motors.
If you're not confident installing
the Digital Rev Limiter yourself, get in touch with Brian and the boys
at Link Automotive as they can assist you, having installed many rev limiters
themselves.
Safety Fast!
Nathan Medhurst
Midget/FWD Register Captain