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Jaguar XJR engine question
NS Dev - 14/7/09 at 12:41 PM

right, any Jag experts out there?

How much leeway is there on the standard fuelling and ignition setup on the supercharged straight 6 X300 XJR engine?

If I were to fit a smaller blower pulley, do I need to remap or is there some leeway on the airflow map and MAP sensor correction map?

Anybody seen it done or know someone that has? I'd hedge my bets that the twin blower v8 would be pretty similar, and I'm sure I've seen small pulley kits for these but I don't know how much leeway there is and I'd rather not melt something (it's not my engine! )

Mr Whippy - 14/7/09 at 01:13 PM

Is there a dump valve to prevent over pressure as if there is then your not going to get any extra boost. I'd also be concerned about the extra compression setting off detonation and putting a hole in a piston or worse

rgrs - 14/7/09 at 02:24 PM

My mate has an xjr running a smaller pulley, without any other mod's. It definately improves the boost.

He imported his kit, pulley and belt from the states, however if you do this keep a closer eye on belt tension as his through the supercharger belt recently which in turn took out another belt as well.

I will speak to him and see if he can give any more info.

Roger

speedyxjs - 14/7/09 at 02:32 PM

quote:
Originally posted by rgrs
My mate has an xjr running a smaller pulley, without any other mod's. It definately improves the boost.

He imported his kit, pulley and belt from the states, however if you do this keep a closer eye on belt tension as his through the supercharger belt recently which in turn took out another belt as well.

I will speak to him and see if he can give any more info.

Roger


That is quite a common mod in the X300/308 community. Your mate probably got it from Jaguarxp.com.

NS Dev - 15/7/09 at 06:38 AM

cheers folks, if you can find out anything rgrs, it would be very welcome, though it sounds like my suspicions are correct, that a tad more blower revs won't upset things too much.