It is tether car and it is absolitly correct they go 200mph in .60 size engines.
World record if I am not wromg is 327 KPH which slightly more then 200MPH.
I have never made tether cars but for 17 years made tether boats and speed there is less then in cars, but still .60 engines go 140 MPH, .15 engine with air prop 200MPH, but water is harder to get good grip then on road.
In fact 2 weekends ago i went to see race of tether cars in LA and saw Steeve O'Donnell were racing tether cars and it was really fast. On .29 engine Steeve almost broke the US national record. Unfortunately track wasn't that good condition and he lost about .5 MPH and record still there ( I think it is still Steeev's previose record).
Very ammesing race and very ammesing hoq those cars built-drive train if you spin it (without motor) by wheels with fingers-will spin more then a minut.
They are also very sensative with track condition, more sensative to weather conditions.
Unfortunately all tether racing (cars and boats) is getting down-no new guys comming there and it will disappear completely soon ( I hope I am wrong-I spent many many years in tether racing and really love it).
Edward