I don’t know if it’s just me , but there’s lack of good informations and guides to upper my power in my jag. If any of you can maybe send a list of key performance mods before a tune would be helpful. I am stock as well

 

Afaik there isn't much. Mina exhausts are well known. I'm looking for a good intake to open up the SC whine a bit, but haven't found anything.

There is also a larger bottom pulley and ECU tune from VelocityAP you can buy that swaps in and adds about 40 hp I believe for the pulley, and i think 100hp total with the ECU tune?

 

Would I be able to just get the pulley and hope to make as much on the dyno , cuz I wanna be safer. And if you find a good intake let me know plz

 

The tune alone will give you 410-420 hp crank
Viuze ,velocity, RSC tuning or Eurocars have great tunes. Plus its very simple and easy to get done. Lower Pulley (Only) is a fantastic addition but more work ...puts you up to 450 + however you must add meth and a better rad . I had killer chiller installed along with exhaust which completely changes the performance... Its much faster than a 4.2 sc v8 xfr
i just wish xf could have access ( similar mufflers) to equal the exhaust note of the Ftype...

ps) you cant do upper and lower on a 3.0... the upper alone is a waste of money as its garners you minimal gains. Lower is amazing for V8 like torque.. remember to up the cooling.

 

There appears to be a fair bit of confusion here about lower pulley vs tune.
A larger crank/lower pulley by itself will NOT give you more power and torque, in fact quite the opposite, it will cause the car to go into limp mode ("restricted performance") as soon as you give it the beans over around 4,500 rpm.
If you fit a larger crank pulley then you MUST get the associated tune to prevent this happening and to reap the benefit of the pulley.
The pulley and tune combo, at least the VAP version, will take it to a safe 450 hp with zero other modifications.
Or you can go with a "tune only" for 410 - 412 hp.

 

I did mine in stages, the tune only then the pulley. Tune only was a wild ride, the Pulley and tune makes it much smoother and pulls like a freight train....

I didn't do anything about cooling. Is there a problem with detonation I did not know about?

 

well i have tested 5 diferent 3.0SC engines both AWD and RWD in XF x250, and x260 also in F-type by no means any of those come close to 4.2sc engine anywhere up to 4000RPM, where 3.0sc with more advanced TVS charger starts opening up, and old generation m112 starts fade away at 5500rpm. a 4.2sc with LSD is agin diferent story.

 

correct information on a STOCK 3.0 however vastly different on a modded 3.0. Having both a Modded 3.9 and a 4.2 i have put them both side by side down the 1320... 4.2- 12.3 @ 125mph vs 3.0 12.1 @ -127
both re-program Ecu, 300 cel cats, pulleys, larger intercooler Meth injection, cat back exhaust, h pipe
.... love the durability of the 4.2 however its limited by the heat sink Eaton blower

 

the mina intake tubes are great and add Significant sc whine... it sounds great without too much drama.

 

the mina intake tubes are great and add Significant sc whine... it sounds great without too much drama.