When ordering a turbo twister, make sure to get the unit reinforced and have the wand set for 4,000 rpms. In order to do this, you will have to order a bigger engine OTHER THAN THE 5 HP that comes with it! The 5 HP will not preform 100% when used with the bigger units of 4,000 psi + with 6 or more GPM's. I would not order the unit stock if you have or plan on having a unit that big or bigger. Like wetfoot experienced, you may have issues with the unit breaking down or only spinning 3,000 RPMs thus slowing your cleaning capabilities downward.
With the proper pressure washer, nothing comes close to the speed and the cleaning capabilities of the turbo twister. I ran them for 19 years and I still have one from 1993/4 of which cleans better then the newer ones we have.
Our custom ones are built to our specs. We buy 2 at a time to keep the cost down. Ours with upgraded specs, the unit cost around $4,000 to $4,300.00. Thats with a 14 HP motor. Our units weigh in at 350 to 400 lbs.
When we turn our machine on, the turbo unit lifts up about a 1/8 of an inch from the steam pressure build up making the unit a little easier to push.