joeyjoejoe

Thanks for the replies!

Some of this info contradicts what the local Hobbytown USA guy told me and my son just yesterday so I will ask a few more questions.
Thrust is the name of the game here. The winning cars all jumped off of the start line despite being verrry heavy. The usable track is actually less than a meter long so there isn't a lot of time to gather speed. If I am understanding you all, I need as big a prop as is possible (which is around 7") with a low pitch (3, 4, 5???) and drive it with very high RPM(15000RPM? not sure what high means).Would a 3-blade model be better than a 2 blade? Our current prop is a two blade prop that is a5.5X4.5 model. Not sure if that is considered a low pitch or not but I do know that each motor pulled 3.5amps under load so I'm betting this is considered a low pitch. All voltages are measured with the motors off prior to the run. We used two 900mah 3.6v 14500 batteries in series (which actually provided 8v when charged) for each motor. I do not know whatour motorwill provide in terms of RPM.

So, without knowing what RPMs you recommend, suppose I chose a 1000 KV motor and ran it off of my8 volt supply. If I am understanding things, this motor under no load would spina t 8000RPM's right?

In regards to the placement of the motors, yes the front prop is only slightly above but directly in front of the rear prop but I can't adjust them to the left or the right since only the propeller can extend outside the track border. We also experienced problems raising the front motor and prop since this raised the COG significantly causing a wobbly, unstable ride. The motor mounts are hollow to limit the problems associated with a placementlike this.

In summary my questions:
7" prop:Agree or disagree
2 blade or 3 blade
What pitch do you recommend
how many RPM should the motor spin?

I actually have more questions about the motor but my head is full right now.....

Thanks again for the help!