I have a limited edition 2005 S-Type 4.2 with the XK8 interior with burnt aluminum vs. the traditional Jag wood. Looking at possibly adding some horsepower, outside of adding a cold air intake and new exhaust system does anyone have some feedback. Also, I will have pictures of my two Jag's posted this weekend.

 

JJ, avoid "Cold Air Intake" or more properly described as a "Hot Under Hood Air Intake". Instead drop in a flat panel K&N air filter and look for areas inside the airbox that can be cleaned up or enlarged i.e sound deadening fins, etc. See if the air intake tube can be straightened out, etc. Replace spark plugs with quality performance spark plugs i.e Denso Iridiums, etc. Use a fully synthetic motor oil. Have an exhaust shop custom fit this affordable but very effective exhaust system: Set of high flow Magnaflow cats (2 1/2" inlet and outlet), Magnaflow 2 1/2" X-pipe, 2 1/2" pipe continues to a pair of Dynomax 2 1/2" inlet/outlet glass packed mufflers (flow through 2 1/2" core tube design), continue with 2 1/2" pipe to a set of Magnaflow straight through mufflers (2 1/2" inlet and outlet), finally fit on a pair of s/s 3" exhaust tips. Last but not least get thee to a dyno-tune shop...here your efforts will be dialed in so your 05 310 hp sleeper will likely put out 330+ hp and 330+ lb/ft trq.? I went to doctor school in Atlanta, GA.

 

You can also try Paramount Performance. They are located in the UK so perhaps one of the members who live in the UK might be able to provide some more insight.

http://www.paramount-performance.com..._Upgrades.html

 

Discussing benefits of K&N filters or synthetic oils is a no-no here as it's been thrashed to death far too often, but there's also nothing to gain in fooling around with spark plugs either.

 

Wow, at Paramounts prices I wouldn't touch 'em, £79 supply only for a K&N panel filter you can get for half the price, and £20 to fit it ! :-0

Having said that, if you're willing to spend the dough, they have a good reputation.