Dyno'ed the W210 E55 yo!
 

I went to The House of Power in huntingtong (www.hopracing.com) and got some stuff done and decided to dyno the car at the same time. My only "performance" mods are K&N air filters, and resonator removal. Although as Josh R, the owner of the shop, pointed out, the repiping wasn't really done well. There are a couple of kinks and the pipe that replace the resonator is sleeved inside the stock metric sized pipes, so they may restrict a bit still, though it's surely 1000's better than having a resonator.

So, after a few runs, the car made 292whp and 301tq (if I recall). I think it's not too bad at all. I don't know what a stock 210 55 put up, but according to MY calculations, given a 20% tranny loss, that would put me at 365hp at the crank.

I don't have a scanner, but I'll try to find a way to get the graphs up on here.

What do you fellow w210 owners run on the dyno?

With my Powerchip I'm at 310hp and 324tq at the wheels.
I think a stock 55 is around 285hp. Your numbers seem better than average.
Mario