My 720 ran its first race this weekend at the track of MBC 'de Sluis' in Gouda
, the Netherlands. The track is fairly tight and techical and traction is a bit below average and it has a few unpleasant bumps. I didn't know what to expect from the car there; the car is fairly new to me and hadn't been quite set up for the track and I spent the training saturday to finish running my new STS D3R engine... Sunday (the race day) I made a last minute decision to leave the setup standard, just add a bit more camber on the front wheels and put on yellow springs in the rear. The car performed quite well and was very easy to drive. There was still a bit of understeer that I have yet to solve, though more drivers (with other cars) suffered from this problem.
I ended up qualifying third, second and second. The first final I got hit at the start and when my car was on the track again everybody was at least half a lap ahead of me. Also, due to (per accident) breaking a track rule I had to do a stop & go, costing me another half lap. When I finally got back into the driving I easily passed the last 7 cars and ended up finishing third. The second final I did not run due to radio problems. One of the other driver's radios turned out to be not quite up to spec and caused some interference for me.
The STS engine was a bit of an experiment for me. I'm used to driving the italian engines, but they are expensive and I decided to try something different for a change.
So far, the engine's performance seems OK. It does not rev very fast, but it has a fair amount power over its entire RPM range. The carb is easy to tune, except during the break-in period. The sound of the engine (I'm using it with an old Mega exhaust) is OK too and it doesn't sound raw or weird in any other way. The speed should still go up a bit when the engine has about 2 litres through it; it has been better every tank so far. I tuned it for good performance yesterday and the running temperature was about 110 degrees celcius.
One thing I'm less satisfied with though, is the internal finish of the engine parts. It all looks cheap, and it's clearly a class less well produced than both my Mega ZX12 and my old NovaMega SX12RT. The engine runs well now, but I'm not entirely sure about its longevity. Only time will tell though...
On the outside, the engine looks great. The cooling head on it is enormous. The feeling of things is right and when turning the engine by hand everything feels smooth with plenty of compression and after running in, just a little pinch near TDC.
If people are interested, I can post some comparison shots of the insides of the three engines I have...