Tech Tip – Spark Plug 101

This is going to be a short “tech-tip”. It is focused on two items.

1. Using race fuel

2. Changing your spark plugs

For most, this article will seem overly obvious...except the fact is most club racers really neglect maintaining their spark plugs. We noticed a performance degradation on our RPSRaceTeam.com GSXR-750 and after looking at various things...the simpliest issue was the main issue!

Most racers use some type of “race fuel”. This includes oxygenated fuels that dramatically increase power on stock motors. RPSRaceTeam.com leans on VP fuels MR-12. This fuel will cost you around $125.00 for 5 gallons and add approximately 3%-8% horsepower depending on engine build and tune. It is especially effective in the mid-range.

The drawback to using this fuel IS THAT YOU MUST REMOVE THE FUEL from the tank and flush the system with something that isn’t “oxygenated”, which usually means “pump fuel”. Although some of the newer pump fuel mixtures arguably can damage your motor too, it pales in comparison to a heavily oxygenated fuel.

RPSRaceTeam.com does its best to completely remove all race fuel from the tank and run pump gas through the system to prevent any excessive wear. At the same time, you can’t get it all out. Surfaces that are sensitive to wear/corrosion cannot be protected from some of the effects of this high HP fuels. Spark Plugs are no exception.

Looking at the photos on the right, the plugs “don’t look too bad”, but look really close…and you will see “some build up” on the leads and overall a slightly darker than desired color. All things being equal, these plugs don’t look bad. At the same time, the conditions of these plugs provide for an opportunity for the engine to not run at maximum efficiency. For preventative measures, it is best to change or inspect plugs every 2^nd or 3^rd weekend of use.

Why we are fans of VP Race Fuels

When we look at the cost of building out a complete motor, bottom line is that a quality build even with “racer discount” is over 3500.00 and generally, that engine is good for MAYBE the season. The net result is gains of over 7% - 12% in HP and generally a “better running engine”.  Basically, that 115bhp 600 may effectively put out 124bhp – 127bhp with gains “across the board” depending on builder skill and experience.

Our experience is that we can gain a solid 4% - 6.5% HP gain with race fuel alone…add in some cam timing…and we can maybe get 9%. So, although we may not get “the full effect” of a race motor, we do get the HP gains for what roughly costs 1500.00 per season and since we can leave the motors stock…they last the whole season with usually no issues. Truthfully, our motors likely could go 2 seasons. The wear we have seen with our Silkolene Pro4 oil has been the best of any oil we have used previously (That includes some of the other "leading brands").

One thing you must do though is flush that fuel out. Change/inspect those plugs every few race weekends…and also check your fuel pump/internal filter. We have found the mesh filter on the Suzuki’s don’t like to be immersed in oxygenated fuel.