E55K Fixed or Clutched S/c Pulley

[merc85]

Whats the pro's and cons of a Fixed S/c Pulley over a clutched one?

Just asking

 

[Alps]

clutched everytime, you will get overheating issues with a fixed pulley.

many people in the US have swapped back to clutched.

 

[AngryDog]

I believe that there have also been mapping issues as well with them.

 

[merc85]

Cheers peeps always worth a ask before doing anything , much apreciated

 

[AMGeed]

^ Somebody wants the 77mm pulley

 

[merc85]

^ Somebody wants the 77mm pulley

Somebody tempted fate again:fail

https://www.mbclub.co.uk/forums/mbclub-projects/215529-brutus-e55k-project-34.html

 

[SMed08]

Been looking back and forth for a while, from what I've read:

Pros:
-Changes driving dynamics for the better, boost always on instantly. People seem to love them now.
-Much smoother, no jerky clutch engagement
-Cheaper as it's much simpler, no need to worry about clutches and bearings etc.

Cons:
-Baseline IATs run about 10-12°F higher at best. Really need max cooling already sorted if you want this to work.
-MPG goes down a couple of points
-Supercharger theoretically will wear out faster
-No actual power or performance benefit



I think there used to be a tuning hiccup issue when these first came out, but nowadays I'm fairly sure it's sorted. Everyone that has them seem to use RaceIQ, they come highly recommended and the hiccup seems to be gone.

 

[ChristopherLembra]

Been looking back and forth for a while, from what I've read:

Pros:
-Changes driving dynamics for the better, boost always on instantly. People seem to love them now.
-Much smoother, no jerky clutch engagement
-Cheaper as it's much simpler, no need to worry about clutches and bearings etc.

Cons:
-Baseline IATs run about 10-12°F higher at best. Really need max cooling already sorted if you want this to work.
-MPG goes down a couple of points
-Supercharger theoretically will wear out faster
-No actual power or performance benefit



I think there used to be a tuning hiccup issue when these first came out, but nowadays I'm fairly sure it's sorted. Everyone that has them seem to use RaceIQ, they come highly recommended and the hiccup seems to be gone.

So fixed pulley doesnt get any extra power for engine except instant torque, more supercharger wear and worse mpg? Doesnt look like a good deal to me

 

[Gbrowncls55]

As I recall (and I could be wrong) when the iat gets too hot for whatever reason (poor pump, too many foot to floor runs in a row) doesnt the supercharger clutch dissengage to protect the engine. With a fixed pulley it will stay engaged until you see a piston come through the bonnet! Given the very limited benefit and the natural increase in IATs from a fixed pulley I would say the risk far outweighs the gain.

 

[hammylove]

As I recall (and I could be wrong) when the iat gets too hot for whatever reason (poor pump, too many foot to floor runs in a row) doesnt the supercharger clutch dissengage to protect the engine. With a fixed pulley it will stay engaged until you see a piston come through the bonnet! Given the very limited benefit and the natural increase in IATs from a fixed pulley I would say the risk far outweighs the gain.

I think supercharger has its own clutch to disengage when too hot?