Ive got an 06 XJR same color and curious about this. If I recall the 05 XJR is supposed to have 390hp (400 in 06 in the US per what I have read) and your car sound great but where was is RWHP wise before you started and what did you do to get it here ? I was following someone elses post about getting to 500hp (doubtful I know) as mine is becoming more of a toy in the family so I might set about making some changes (pulley, exhaust, cats, ect.) so what were the big things you did?

 

John Fox you have an extra 10hp because of VVT which the 2005 XJR does not have.

Also the ECU is totally different on the 2006 and is still "tune-able" which the 2005 is not, at least by reputable tuners with the exception of Cambo in this forum.

Also Cambo has stated that tuning the 2005 XJR ECU does not realize anywhere near the gains that are possible on the 2006 MY mostly because of the VVT on the 2006 MY.

So options for tuning a 2005 XJR are a little more limited but are available. It will be interesting to see what jazzyjags has done.

Have a look in this thread for lots of info: https://www.jaguarforums.com/forum/x...epower-168474/

 

Greetings John. Good choice in color


Unfortunately I never took it to get a baseline dyno. But I have seen many post and a couple videos of XJRs and STRs putting down between 310 and 320 rwhp stock on the same type of dyno. At a 20% drivetrain loss, 390 crank hp calculates to 312 rwhp. So I believe that's pretty close. I have other videos of pulls after some mods though. The more noticeable difference was between my last 2 sessions.


352 rwhp/ 338 tq


After tune and electric exhaust cutouts:


368 rwhp/ 383 tq


I feel like the tune finally allowed the car to accept the mods and make the best of them. The biggest impact was the increase in Tq at 45 ft lbs. Makes it feel like it pulls plenty harder. The mods I have are:


6% supercharger pulley
Ported Supercharger
180*F thermostat
Bosch 010 Aux coolant pump upgrade (did both pumps by accident)
Mina gallery intake elbow and shield
RangeRover upper intake tube
Velocity stack to filter
Catalytic converter delete
J-Spacers on O2 sensors
Center resonator delete, replace w/ Magnaflow X-pipe
Rear muffler delete replace w/ Flowmatser 10's
Electric cutouts right after upstream O2s (terribly loud)
Paramount performance tune




I think that's it as far as performance mods, the rest are suspension, wheels, other cosmetic etc.


One of the main contributors is maintenance and cleaning. I took apart the entire intake and intercooler assembly in late November and cleaned everything spotless. I had another set of intercoolers I had been cleaning for weeks that ended up looking brand new. The ones I had on the engine were soiled with oil and gunk. This helped with the cooling efficiency, when I dynode 352, I had the exact same number all 3 pulls. The throttle body and plenum both got cleaned as well.


Just have to make sure everything is sealed and clamped up really well. These cars will throw and CEL or restricted for anything.


Let me know if I can answer any more questions! Thanks

 

Quote:"One of the main contributors is maintenance and cleaning. I took apart the entire intake and intercooler assembly in late November and cleaned everything spotless. I had another set of intercoolers I had been cleaning for weeks that ended up looking brand new. The ones I had on the engine were soiled with oil and gunk. This helped with the cooling efficiency, when I dynode 352, I had the exact same number all 3 pulls. The throttle body and plenum both got cleaned as well".

Totally agree I did the same and now have an oil catch can on the high load breather hose which does catch oil.

The oil/gunk build up was pretty severe on my charge coolers at around 100k miles.

See pic of the inlet elbow when I first dismantled everything.