I only can dream of something like that, but as you said - right time, right spot and "...enough: Want really bad!"
# On the weight cert. it says - drive axle / trailer axle
# In the pictures both hubs on the rear axles look like drives...? The Front are drives, the rear is only Tag.
At the hp you are getting, I wonder if there is any regular road axle that will take that power!? So, what do you have? These coach's were already set up for the optional ISX600 engines, including the Axels
1 drive axle and the other a tag-axle or 2 drive-axles?
Which one is the drive-axle (front/rear)? Front drive
Can you lift the tag-axle? (I assume you have air-suspension all around?) Yes, but it doesnt actually lift up, just releases the air to there isnt much weight on it
In the video-clip where you have trouble moving (body-shop) on ice/snow, I cannot see any of the rear wheels spinning, so I assume you do not have a locker in the drive-axle either? [The spinning wheel would have been on the other side....]
[...where I come from, many folks live from winter tourism (Austrian Alps) - lots of them are shipped in/out by bus - over the decades bus operators learned their lesson: I dont think I have a lock button, but I might.... still learning. There are alot of buttons
1st ... get the tag-axles to lift! That lets you put more pressure on the ground with the drive-axle and/or at least doesn't let the tag-axle high-center on a uneven parking lot and the drive in the air!
2nd ... invest in a diff-lock! Even with the tag in the air they still got one wheel to spin on ice - though I never saw a locker equipped bus not getting of the parking lot! Looks funny when they "drift" around the lot! [...that's a very slow drift on ice, until they got to the area with gravel thrown on...]
Do you have any mp/g - l/100km numbers yet? I seem to be getting about 7.5-8MPG
675hp on 50k lbs - you have a rocket ship! Absolutley....it moves!! and doesnt change gears on hills ;)
[The heaviest I ever got to move was a total of 84 tons[metric] VGW with an excavator on the back - that was with a 520hp DAF truck - ....and I thought I was moving nicely!]
Keep us posted!!