Lost boost on track it was sudden and the car wouldnt go past 5psi and sounded strange. I figured it was the harmonic balancer so I Limped home couldnt go past 1/8 throttle. about 75 miles into the drive I got a check engine and it triggered limp mode, 100 miles later the belt snapped, got towed the last 40 miles.

Car runs ok without the belt, 2005 R53 with 17% pulley and the crank pulley looks fine, do these facelift pulleys fail like the early cars? supercharger feels fine I'm gonna pull it off later tonight

I suspect the supercharger has something wrong internal, I pulled the intercooler and there is no metal shavings to be seen so that's a good thing

 

How long was the belt on there?

 

Two weeks, it must have broke cords the sound appears to have been belt slip, never broke one before now I know what it'll behave like

 

What codes came back when you pulled them?

The facelift pulleys fail more often in my opinion. I've only replaced a handful of the 02-04 pulleys, but I have replaced countless 05+ pulleys.

Check for contact between the crank pulley and timing cover, as well as deflection in the two halves of the pulley, proper belt tension, make sure the SC pulley isn't slipping on the shaft, no bearing problems with the alternator or idler pulley.

If you had a problem with the SC internally, 9 out of 10 times there is a horrendous noise that will verify your thoughts.

 

I'm gonna order the ATI and the tools to change it out, I dont want another weekend cut short

 

Have you diagnosed it as your problem? Not that replacing it as PM is a bad idea anyway at this age.

We do have everything on hand as far as the rental tools and ATI damper, if you ordered in the next half hour we could get it out on todays truck.

 

my current damper is fine, replaced the belt with a spare jcw belt and it makes 10psi then slips, waiting on new correct size belts now