In this thread has some more info that could be of help:
https://www.jaguarforums.com/forum/j...k-4-2-a-23763/

 

Really appriciate the engagement in this thread, was just about to write it is beyond my expectations but no. This forum always delivers! 👍

 

After some research on the internet, the only company I can find offering a remap for the 4.0 SC engine is Swallows Jag. They have a package consisting of race cats, lower pulley, high Flow air filter and a remap.

https://www.swallows-jag.co.uk/parts-shop/swallows-racing-stage-3-package-for-jaguar-xkr-x100-4-0ltr

From what I understood reading a lot of threads here at the forum, it is virtually impossible to remap the 4.0. Any thoughts on this? Anyone here that tried the remap from Swallows jag?

 

Higgins,
Several Companies are offering the speed Pulleys for the Crank and S/C and a couple that offer the Big Intercooler and Pump....but no one to my knowledge offers a remapped 4.0 liter ECU anymore....Eurotek Designs had the equipment and did remap quite a few for those that bought their Pulley Kit Program and they also did a number of them for a couple other Speed Shops that sold a similar Kit but the Equipment they used stopped working (Broke) some time back and they decided to discontinue the 4.0 Liter Re-Mapping program...They still have this program for the 4.2 Engine and it works very good.....My current XKR has their system installed and I have had no problems with the system. I also installed the Snow Methanol/Water Injector system, which helps even more! I make sure to change the S/C Oil every 15,000 Miles, as the Bearings are spinning much faster than originally. As to Swallows Jag, I know nothing about their Company. This could be the opportunity for them to enter into the conversation and tell us about themselves.....

Billy Clyde in Houston

 

" from 390bhp to 465bhp* This is a bit odd if they are talking about 4.0 - not 4.2. It's very difficult to get 465bhp from a 4.0 with Eaton with the listed mods. Stock 100K+ engine gives most often under 350bhp as stock.

 

+1 on the above.

As far as remapping the ECU is concerned I did a lot of research to see if I could find a reputable company to reflash my 2005 XJR ECU.

All but one company said no as they now focus on 2006 plus Jaguar ECUs and no longer on prior years.

2006 is when Jaguar changed the electronics significantly in the XJR so the ECU is a completely different beast in the 2006 compared to the 2005. along with VVT.

The one company,in the UK, that said they could do it advised me that it would be 50/50 as to whether it would work.

Have a look at "quest for 450 hp" in this forum. A lot of info there also view from Cambo, a very respected member of this forum, does not think a remap of a 2005 ECU would gain that much,for good reason.

 

not interested. the only real difference is going to a 5.0 SC, but then you have lost the comfortable seats and now have mediocre hard leather seats like every other "leather" interior made since the 2010 era. And all the recaro seats add is the ability to squish the seat to your form, no added comfort at all for long periods as these cars were intended.

Jaguar has pandered to the "racing crowd" with their later models and in doing so have lost their one glorious shot at their unique place in the car world when Ford fixed them.

People forget, if you want a more powerful Jaguar and are willing to lose the Jaguar comfort, you go buy a Porsche.

 

“……. So when my 4.0 engine eventually is worn out, what option should I go for if I also want to upgrade to a higher spec?…..”[/QUOTE]


I think your are going to have a long long wait ahead of you waiting for the 4.0 engine to wear out.


my ‘02 XKR is at 174,000 and hardly broken in. Life expectancy shouldn’t be any less than 500,000 miles.

when mine is worn out, and if I’m not too feeble to drive, I’ll be wanting another 4.0 that’s had the known issues already dealt with by previous owners , just like they were with my current ‘02 XKR.

The 02 may not have the 4.2 engine, but I don’t miss that , and the 4.0 XKR has the better (Mercedes) transmission in my view

styling wise, the 4.0 cars have the best , with the 4.2 and 5.0 the styling gets more and more “confused” lacking the elegance of the 4.0 XKR.


Z

 

Regarding upgrades, recently did some regular maintenance and upgrades, and had a pro independent look into ECU programing. He has a contract with firm that provides all of the dealer updates, flashes and programing through his equipment. He also has access to Jaguar specific diagnostic, TSB, engineers, etc. and can make technical queries. I was interested in rest-of-world ECU tuning to get the performance that a European or other market car would normally have from the factory. It was important that my vehicle would still pass the emissions test common in many USA states whereby they plug into the diagnostic port and obtain the readiness codes reading.

What he found is that this is indeed possible, however i would have to change my USA (and any other country with similar standards) catalysts to a rest-of-world spec or else changing the ECU programing would overheat the original OEM units. Since mine are just fine, we decided to hold off on this modification if and until they fail. This applies to both the XK8 and XKR 2002 and earlier. We did not investigate the 4.2L or higher bit rate ECU cars for our purposes.

I did one mod that gives an nice improvement without losing any of the elegance or composure of the car which was concern in this case. My exhaust had two welds failing at the small resonators just before the rear axles. Decided to take the risk and ordered the Adamesh Stage 2 piping. Note that i kept my rear most boxes which are usually replaced by the Adamesh Stage 1 piping. The difference is notable and i did before and after dyno testing for fun. It is not much more, about 30 HP, however the mid-range torque improved, higher, flatter. What one notices is that the transmission does not downshift as much when one is passing at highway speed. I would say that it is like the 4.2L in this regard. The engine winds up into the higher bands a little more quickly. it feels a lot more fun when pushed. Note that i did this testing with earplugs, so that i would not be fooled by sound to think more performance.

Now the sound is wonderful. Not louder at all which would have me put everything back. I hate noise. No drone at any speed. What one gets whether the roof is open or closed is the slightest low note rumble which is not obnoxious at all. It is almost just what it needed while still being country-club class.

Even town driving and local road play the car feels just a little more open. Remember that i changed nothing else performance or tune related.

The Adamesh pipes are very high quality and nicely formed. I welded the joints as the clamps cluttered things up a little too much, and i am just a little nuts.

On an XKR this will definitely make a difference of larger magnitude.

One final thing while we are talking about upgrades and fixing stuff. People here have mentioned being concerned when electrics and sensors and certain modules such as ignition are un-obtanium and not rebuild-able. A solution found me by chance. Was helping some guys seat valves on a modern era Nissan Z car that they were doing an excellent job restoring and upgrading. We were talking shop and i mentioned needing to rewire the ignition loom. These guys also know car electrics and computer. Firstly they had very good advice on the proper way to splice harnesses, next advised a thicker gauge wire and other things. One fellow mentioned that i might want to consider better ignition igniters and modules. I mentioned that i did not want a screwed-up car (said it more profanely) that could not pass emission testing or be on-board diagnosed even for things such as misfire, etc. Answer: no problem, everything would work as OEM, only much better and easier to service. They were in the process of upgrading the already complex Z car to a much later model's computer system which had more engine sensors for even better management. I asked what would happen if some odd-ball sensor was unavailable for my car. They sincerely doubted that it could not be sourced, however said that a substitute could be integrated into the system and be setup no problem or the data drawn from elsewhere if there was a good reason.

Uh, so we have no concern over finding spares or things not working in later years. And, many of the cars will soon be so old as to not require emissions testing which does open up all sorts of possibilities if one wants to go there. Not my thing, i like air, but there will always be options.

Do not sell short putting more into a car than it is worth. It may seem odd to put 7 to 10000 USD into a car worth less than that, however one knows what he has and what he might never be able to find this cheap ever again. Remember what we paid new for these cars, replace with a new one now? If a person can get a great hull sans working engine and be into it for 20000 USD, he has purchased a car where he knows exactly how everything has been done for less than most economy cars of today.

SIDE NOTE: it would be appreciated if someone could tell me how to contact the moderator of this section of the forum. I have a personal request. Thank you.

 

I'm surprised the Adamesh exhaust gives you 30HP. I shouldn't really because when I took mine off the over axles are very crushed. Nice to know though that we get such a big performance increase. Well worth the money I spent for the sound alone but now I know it makes 30hp more that's even better.

 

I’d have to be at the dyno testing session to believe there was a 30 HP improvement.

Just naturally skeptical of any and all HP claims.


Z

 

StuG and Jkline398,

If anyone would like to change out their 4.0 for a 4.2, there is a very good explanation of the things that have to be done and where you can get the Parts to do it at DCR in Scotland...Go to Dave's Website and you will find an article on this, along with a list of the Parts you will need to accomplish this switch over. Even if you don't plan to do this switch-over....It is an interesting read! DCR Jaguar XK8 XKR Parts and Accessories....Looks like Dave has just about everything you would need to make the switch over or just about everything you would ever need for a Jaguar X-100!

Billy Clyde @ Cinco Ranch

 

Link ?

 

Hey Z,
Don't tell me you don't have Dave's email......

https://www.xk8-parts.com/about/

Billy Clyde..............

 

Wow, I do have it, just couldn’t find it at first.

Z