Our 2009 season was hardly disappointing, all things considered, least of all in the engine department where we seemed to be as strong as anyone else. For the 2010 season we aimed to improve aspects of the engine following an analysis of the dry sumping and oil pump arrangment. Two revisions were played with early in 2009, and the lessons learnt encouraged us to develop a new revision that will debut in the Dallara at a test day during March 2010. We have made noticeable gains in oil pressure and power output, all of which will help in our challenge for the 2010 Mono2000 championship. The engine has been run in on the Dyno this week (albeit on carburettors for simplicities sake), and is now ready to race!

As the 2010 Monoposto rules are allowing fuel injection, we are evaluating making the change. Whilst the carburettor rules allowed any size of throttle butterfly, throttle bodies are limited to 40mm diameter.  In 2009 we were using 48mm bodies with 41mm chokes, so it was going to be close whether injection would be an improvement.

To determine this, we’ve used a spare “donor” head, some old valves, some plasticine, our 48mm carbs, and a set of throttle bodies, all mounted, in various configurations, on a flow testing bench.  The results are, obviously, not the whole story, as air flow in a real engine is not steady state. In principle though, the air flow tests give an indication of potential power and torque outputs.

So, what did it tell us? Well, as we predicted the results are very close, but we believe that on our engine, with our manifold, that throttle bodies will give equal or marginally better performance, particularly in terms of “mid-range torque”, which is where our Toyota engine seemed to be lacking compared to the Vauxhall XE engines used by our competitors.  The other benefit of injection is that they are immune to lateral-G influences. Carburettors (or, at least, our carburettors) didn’t like very high-G cornering @2.5G, and at the beginning of the season they went rich above 2.0G.  Having reliable power in high speed curves will not only improve tractive effort in said corners, but bring about an improvement in balance as well.

The actual benefits (or otherwise) won’t be known until (unless) we commit to injection, map the fuelling and ignition, and get a torque output curve, which is probably the next thing to worry about.

With a last minute panic – a deadline always concentrates the mind – we finished the car ready for the rolling road on Wednesday. The ECU was syncronised with the engine, the dashboard was configured, the airbox was fitted with its filter and bolted onto the carburettors, some heat shielding was fitted to the floor around the exhaust, brake pads were milled and fitted, and a set of wheels bolted on. Leaving early on Thursday to arrive in good time, it was a fairly simple matter to get the car on the rollers, strapped down and chocked, and fired up…