I've only seen a few of that brand car around, they seem to work ok so prob was setup right from the get go. Let me know on what your IC measurment is on it.
IMO put the biggest tire you can on it, more tire=more consistent to me, launch it around 4200-4400, to many times I see people getting carried away wanting to leave at 5,000 like these bb's are sb's and all it goes is make it inconsistent.