I’ve seen on EBay and a couple of internet sites that have a “Jaguar F-Type 5.0 S 7.5% Supercharger Upper Pulley Peformance Upgrade X152” for sale. They say supercharger speed increase by 7.5% and it gives you 25 bhp without needing to re-map your tuning. Any words of wisdom or caution?

 

There are a few different SC pulley's on the market. Most of the stainless steel ones that do not have the griptec coating on them are known to slip, so I would give some caution there. The old expression is the cheap comes out expensive. Velocity AP and other tuners have used the all stainless steel ones in the past, however as far as I know, Velocity AP is the only one that now offers the griptec coated versions. Much easier install too with only having to heat up and install the center stainless steel hub and then bolting the pulley onto that.

For my money (and what I have done) that would be the route I would suggest going. Those other pulleys are not wrong, you could simply spin the SC faster to create more boost, but without the proper tune to adjust other values to make everything sync up, you are not maximizing your efficiency nor are you taking the necessary precautions you might consider. That is why many do not like to offer a pulley only without the tune. Just my 2 cents.

 

I would never install a pulley without a tune. You might check with VAP?
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