I was wondering what all you 4.0 owners have been doing to gain a few extra kilowatts out of your jags? Now before you all say why bother or get a str i just want to say that not all of us have such a luxury. I understand the strength of the tranny is a bit of a limiting factor but i'm not after oodles of grunt, just a little extra. I have done a bit of searching and i cant find any extractors/headers on the market anywhere? have any of you had any experience with porting/camming the 4.0? cheers,

 

Most Jag owners do not Soup up thier cars and there are not enough Jags out there for a company to warrant making headers, manifolds, etc. There are a few companies that make CAT back exhaust systems and a cold intake system but the name is out of my head at the moment. Someone else on this site can probably tell you.the only other way would be a specialty shop that does custom work and that would cost you $$$$. Good luck

 

I'm adding a Munstang K&N intake for induction growl more than power. I don't want a droning or burbling exhaust.

Power? It's cheaper to sell and then buy at ST-r and slap a pulley on it!

 

Have any of you out there cammed or ported their 4.0?

 

Michael, I'm not quite sure you appreciate what it would take to "cam and port" a DOHC V8 with Continous Variable Cam timing and an extremely advanced valvetrain and induction system. You realize this thing is making 70hp/Liter naturally aspirated right? Just to take a look at some other high perf. engines specific output...

2006 5.7L Chrysler Hemi = 60hp/L
2006 6.1L Chrysler Hemi = 69hp/L
2004 Ford 4.6L (Mach 1) = 66hp/L

The layout and highly advanced egineering already present make anything but external "bolt-on" modifications out of the realm of possibility for anyone who doesn't have a full on race engine building shop and thousands of dollars in R&D money readily available.

 

thanx very much for the info. i get where your coming from now