We generally recommend motors that can get into the gearing range the cars were designed around. It's not so much that the motor isnt' capable, rather we've seen so many people not understand gearing and kv together with the battery voltage to understand what's going on.

The 1700 can run 6s, but you must gear the car correctly.

For example you're using a 1/8 buggy which was primarily designed around a nitro .21 engine. Those engines spin between 5,000 and say 45,000 topped out. Knowing that you can see why having a 6s 2250 setup in one creates the issue where the 56,000+ RPM. See the issue? The extra 11,000 rpm doesn't seem like much but the gearing will need to drop into the 11-12T pinion range. It maybe possible but you'll be much better served long term with a lower kv motor on 6s, such as the 1400 or 1700; 35,000 and 42,000kv respectively.

1/8 cars were never meant to hit speeds of 80+ MPH. The cars aero and other features hold it back from these speeds. I know it's fun as heck. Generally we also see guys skimp on the batteries and try to run inexpensive packs with less than true 40c which can over work the ESC under these loads.

I hope this info helps.