fruitsalt

Hi guys,
I’ve had to bring my E55 back to stock since I have a date with the state ref.

I currently can not locate my stock supercharger pulley and new ones are $1k+

What I do have is a 88mm UDP super charger pulley.
I was wondering if I can use that with a stock tune/setup and if there are any adverse affects of having a 2mm smaller super charger pulley for a short time period ?

If using the 88mm pulley short term is ok then what about using it long term, would that risk damaging the motor/supercharger ?
Thank you

GinDistiller

You're fine short term, just don't push it to full boost or get it on a dyno etc, the ecu shouldn't notice a big difference when driving.

I wouldn't run long term because it can possibly mess with your fuel trims too much, and could shut you down for an over-boost condition when driving hard.

Exotic-metal55

The 88mm is designed as an upgraded OEM replacement supercharger pulley. 2mm is about the same as changing to high flow air filters and your ECU has room to adjust for small changes . Just like it does for air intakes or high flow filters. The 88mm is a lot lighter being made out of billet , so you will free up power by reducing the rotating mass a lot of the supercharger pulley and that also does not effect the tune. I

fruitsalt

Thank you, I just need to make my state ref appointment and then can look for a genuine one.

Thank you for the input, I will use the 88mm to make my appointment.

ArmoE55

Exotic nailed it, but you will be fine with the 88mm. You'd have to have a damn good 'butt dyno' to feel a power difference though, especially with no tune!