Hi Guys. I am finally getting around to doing the supercharger pulley mod. Sorry if this has been asked before I couldn't find the info I wanted from the search function.

Does anyone know what the psi runs at on the 4.2 standard?
Anyone recommend where to get the pulley from?
What psi increase can I expect and what is safe?
Would I have to do an ecu tune to account for the psi increase. Or is it small enough for the ecu to be happy as is.

I believe that with the pulley mod the engine will run hotter. But not that much to cause a problem.

Sorry for all the questions. If anyone who has done the mod could give advise that would be fantastic. Do you think the mod was worth it.

Cheers.

 

I got my 3 lb pulley from a UK vendor.

According to him factory pulley is roughly 11-12 psi. (I believe this is true for both pre and post 2010 models)

There are 2 pulleys sold for the XKR, a 1.5 lb and a 3 lb.

So the 1.5lb should put you at 12.5-13.5 psi and the 3lb at 14-15psi.

I highly recommend getting a tune with the pulley upgrade otherwise the ecu will retard performance once the boost hits the OEM set max boost level.

I haven't tuned yet and I can tell I'm not getting the added performance I should with the 3lb pulley.

I plan on mailing my ECU to Viezu UK to fix this. Due to my location this is my only tuning option plus they are the pioneers of Jaguar ECU Tuning.

You do however have more options stateside like RSC, Eurocharged, ETG etc...

I know Eurotoys offers a pulley and Viezu tune combo as well.

BOL

 

I have heard the ecu can retard the ignition on mod pulley. Do you have any temperature related issues? Cheers