If anyone has a 4.2 like me get this done. Can't believe the difference. It has turned my car into a missile, with the pulley and remap i have gained nearly 55 more bhp and 75 of torque and the remap was tuned in to my performance exhaust. The only mod i had was the performance exhaust. Top end is near the same ,but lower end is astonishing. The slightest touch of throttle and it's gone. Seems to change up the gears quicker and smother. The power up to 3,000 revs is massive. It's just hard to describe, simply amazing.
The snout of the supercharger had to be filed down by 2mm all round for the small pulley. I bought the pulley of powerhouseuk. They told me it could be fitted without removing the supercharger , but it is impossible to get a good job done this way and would have caused a mess.
The guy who done it for me (Ken) took the supercharger off and did it on a bench. The coolant had to be drained and throttle body taken off and another few pieces. The supercharger belt still fitted when the work was finished.
He also saw that the throttle body was filthy so he cleaned it. Jaguar say this isn't possible because of a coating on the body, but this is not the case. It all depends on the person doing the job. Ken ultra sonic cleaned it. I used to have a rough idle a bit and now it gone , smooth.
I drove the car home and have put nearly 200 miles on since done and the mpg has even improved. I was getting 19.5 to 19.9, now it has gone up up believe it or not 26mpg.
Ken also changed my transmission filter and oil and did the rear diff oil. He showed me the magnets on the filter and they were near spotless, good news and this is a car with 82,000 miles.
All and all i'm delighted .

 

Sounds almost too good to be true!

 

Superb stuff and a HUGE smile on your face no doubt?


I've remapped several cars ( diesels ) that don't have anywhere near the power you had to start with, but they were remapped giving greater bhp and much greater torque......wow


Highly recommend it for sure.

 

I was waiting for the results of this. The pulley supplier you used are only 20 mins from me so for once it would be a convenient mod if I decide to do it. I was thinking just the basic pulley with no S/C mods to start with.
Glad it's worked out!

 

Thanks guys, i'm really happy with results, I was a bit spectacle about doing it and the work ahead. But when i arrived at Kens garage i was at ease when i saw what was parked outside for services. 3 Ferrari's, 3 Aston's, 2 Bentley's, 2 Maserati's, a Hummer and 3 Porsche's. He should me a Lamborghini diablo engine he was rebuilding , a great skill. So i was happy to have him do the job.
My wife went for a run this morning, when she came back she said the car was way faster, more responsive. Had a listen to the car as my wife drove away, there is about a mile of winding road before motorway and she gave it some. What i noticed was a nicer crackle to the exhaust noise, maybe due to remap. If anyone gets this done they won't be disappointed.

 

Have a before and after dyno chart? What are the details on the map? Is it a custom tune?

Thanks!

 

Yes, very curious to see the A/F readings before and after if you are able to locate them. Any boost readings vs RPM would be great as well.
I've been debating on the 2.5 lb pulley myself.
Do you know what software they were using to remap the ECU? Was it a dropped in tune from a provider?

 

Is there a difference on the road??

Thanks for the thread.