Hi All.
I have now had info back from the various companies (UK and USA) that can supply me a top s/c pulley.
However I have different advise on whether I need to do an ECU tune.
Chris from Mina says that an ECU tune is not necessary or even recommended. He says these cars ECU's are best left alone.
Really could do with you opinions/advise before I go ahead.
xkr 4.2 s/c
Cheers

 

Anyone any advise? Must be someone out there who has done a surcharger pulley mod on a 4.2.

 

Have you done a "search" or checked the other forums yet?

 

Yes I did a search and sifted through as best I could. I found a lot to do with the 5 ltr but not what I was after for the 4.2. I was hoping someone with a 4.2 who has done this mod could help. I did get some good info from Powerhouse Automotive in UK. Cheers.

 

I've never heard of anyone having any issues with the pre-07 models.

I'm not sure if there are significant changes with the pcm or not.

However with modern cars the pcm is very good at continuously adjusting the ignition and fuel delivery according to different circumstances.

I think you should go ahead and give it a try, worst case you can always resort back to the original pulley unless it requires you to grind the snout.

I do not know what kind of pulley you intend on installing.

I have heard that with some you need to grind the snout to fit a smaller pulley so in that case you would be SOL if you have issues.

I have never installed a smaller supercharger pulley so I am no source of wisdom on this matter.

Why do you want to change the pulley?

I find these cars are very well built and even with my old XKR I have never found myself seeking extra power on public roads.

 

I always try to find ways of possibly improving on what is already there. I have improved the power on N/A engines (cams, carbs etc) back in the day. Had a go at turbo's but never a supercharger. Seemed like the perfect opportunity. It should be a easy way to gain extra power. The pulley I am planning on going for needs the snout mod doing. So once started no going back. That's why I am trying to find info from anyone who has done the 4.2 pulley mod. Not had much of a response unfortunately.

 

This is a quote form another thread, Nick seems to have a great amount of knowledge.

MOSCOWLEAPER
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Well, on a 5.0SC engines there's a software limiter. A 4.2SC is a totally different engine, w/o such a limiter. You could install a pulley, it'll give some more hp even w/o ECU tune.
Actually a 4.2SC software is quite flexible, it handles even a twinscrew supercharger (on a X350 and X100) w/o reflashing.
Later, when i'll have some money for experiments (4-5 month later) i'll try to install a twinscrew on mine XKR. Based on experince of a guys in a X308/X350/X100 section it gives a huge gain of power.
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1994 Jaguar XJ6 4.0 - SOLD
2001 Jaguar XJ8 4.0 - daily driver, with new engine, rebuild tranny, suspension and everything else - SOLD.
2004 Jaguar S-type 3.0 - bought for a wife. Mint condition . My ex-wife owns it now.
2008 Jaguar XKR Coupe. Low milage, clean history.