Hey guys, just bought my 1999 xk8 and it just doesn't have any growl or punch to it. just looking for some upgrades I could do to give it a little more of a bite

 

Before you think about modding, make sure the car is running the way it should be:

-Make sure the throttle and kickdown are adjusted properly: https://www.jaguarforums.com/forum/x...estored-38663/

-Check for fault codes with an OBDII reader and correct any problems it may have.

-If you have high mileage, a fresh set of plugs will help.

-Run a can of BG-44K with a full tank of gas to clean the injectors (or better yet have them professionally cleaned)

-Put in a clean air filter.

-Make sure you are driving with Sport mode on.

-Start driving more agressively, the vehicle is adaptive and will start reponding more agressively with time.

Then spend the money to ugrade the secondary tensioners to protect your engine before you spend on modding.

Search the forum, there are exhaust upgrades that will give you some growl.

 

+1 on making sure everything is good. Sorting out new issues from old can be a nightmare.

 

The car is at just over 61000 miles. There are brand new fuel injectors on the car, new air filter, new water pump, new timing chains tensioners and a few other things. I will check out the throttle body but everything is running very well on the car (including the RC antenna sadly) Just wondering if anyone has any reccomendations for muffler or exhaust changes to give it more of a growl

 

plenty of threads out on this forum; here's my latest: https://www.jaguarforums.com/forum/x...ey-goes-96012/

 

I agree that we are opening ourselves up to unknown bad events with just removing the pipes and having exhaust gases disbursing under the car or wherever, as keestanis had mentioned doing. My concern is based more on the potential of the driver or a passenger experiencing death as a result of CO poisoning (carbon monoxide). With the top up, engine running and parked long enough, you run the risk of being on the front page of the newspaper. I guess I'm saying do it right... or not at all. I base my opinion on what little I've learned over the years as a US Army Aviation Safety Officer w.Accident investigation training and OSHA. There's my wooden nickle's worth.

 

Bob is right. You don't dump exhaust out under the car or by a gas tank. All my work is being professionally done. If I could weld it might be a different story. No clamps on my exhaust. Everything is welded.

 

On the antenna many of us has disabled it with a switch, see https://www.jaguarforums.com/forum/x...antenna-24564/

regards

 

You can delete any of the mufflers/resonators you want, but keep the piping out the back. Also, it looks wrong without tailpipes, imo.


^^^^

This is one of the best single posts I've yet seen on this forum.

 

On my 2002 XK8 the prior owner deleted the rear resonators. The pipes still go out the back with a couple chrome tips. To my ear it sounds just right. Quiet when driven slow, growl,s when prodded. Cheap mod too.

 

Thanks all for indicating the concerns wrt just dumping the mufflers; This is an area were safety goes first, no doubts.

As promised in my little thread, I will measure the exhaust temp, AND will ask some Process Engineers at my work to do some risk assessments. Just for the heck of it, because stubborn little me can only think of some extra gas fumes being vented, far away from any ignition source an probably way under the LEL.... But hey, I.m an amateur and this is about potential lethal stuff.

As for the CO (heavier than air) I would still like to understand how (e.g. in extreme windless scenarios, with the top down) this would accumulate in the cabin and deprive a person from O2.

With the cabin closed and no guaraantees of the bottom being gas tight, I'm not so confident.

To make y'all stop worrying about my safety, you'll be happy to learn that today my straight pipes and flexes arrived; Main reasons mentioned above, AND I need a project...

 

For the sake of completeness, though it does not apply to Michael's queston on an XK8, to make sure you have maximum power on an unmodified XKR, add these items to the list above (more info can be found by searching for discussions on these items on the forum):

-Check for proper operation of the intercooler pump.

-Check that your fuel pump #2 is operating on the 4.0l XKRs.

-Check that the charge air cooler intake ducts are not leaking (see attached TSB)

-Replace the belt on the supercharger if it is old to make sure it is not slipping