Jr25

My Feedback: (7)

Although I have been a member or this forum for some time, this is my first post, so if this is the wrong forum, please redirect me. Ok, here is the deal. My local club hosts 4 Star 40 races throughout the summer. The rules of competition include: must be a stock built (per the Sig plan kit) plane weighing no less than 4 3/4 lbs without fuel, a stock Supertiger GS40 engine with stock muffler, stock carb, stock exhaust and cannot exceed 15k rpms on the ground, a Master Airscrew 10x6 prop, and fuel containing no more than 15% nitro. Other than this, we can change the bearings, however, the head gasket must remain in place. Now that you know the rules, a little about the reason for my post. Our first race was 2 weeks ago, and although I did not enter, I went to the field to watch. I left with the impression that the secret to success was in making tight corners, and flying a smooth and level pattern. However, today while at the field, 4 of us had 4 Star 40's with us. Two of the 4 are extremely competitve in all the events and wanted to have a friendly race. My plane weights in right at 4 3/4 lbs, and I have a stock ST 40 with a punched out exhaust baffle, and have my exhaust pipe mounted 5/8" outward of the flange. Other than this it is straight out of the box. The 2 who are extremely competive are running Italian made ST 40's which are also legal. Long story short is I ran a pretty clean race and was able to keep up for about 5 laps. After this, they got tired of playing, and in a 10 lap race finished well over a 1/2 lap ahead of me. If your still reading, my question is this. I use to race dirt track stock cars, and know that local competitors will share some secrets, but they usually keep the really good ones to themselves. What tweeks/modifications can I make to my ST 40 get more power and speed? Does the Italian version of the ST 40 run that much better? Final thing is my engine was tuned and running really well. I was turning right at 14700rpm, didn't bog or loose time in the corners, but was instead out performed. I brought a Nationwide car to a Cup series race. Keep in mind, there is no tear down or claim rule in these competitions, and although the winning prize is pittance, I would love to put somthing out there to at least compete.

Thanks in advance for reading this long post, and for any feedback your willing to share.

Jr

dhal22

the pylon racing forum is probably a better fit for this question. the 40 size engines are a large part of their world. good luck.

david

burgh_guy61

My Feedback: (11)

Another place to get tricks and tweeks is the extreme speed prop plane forum. They are a nice bunch of guys and willing to help with stuff like this also.