Hey chaps


I am looking at modifying my recently acquired 2006 XJR 4.2 Supercharged.
Who has successfully modded theirs?


I want to stiffen the suspension up a bit and replace the problematic air suspension with full adjustable traditional coil overs.

I want to get extra power out of it. I will get the full exhaust replaced, i am just worried the engine light will stay on. Unless I weld the sensors to the new exhaust.

I am looking at putting a K&N induction kit. Any suggestions as to what works best?

I would like to replace the Pulleys on the Supercharger. Are there different size options, What is recommended?

Is it worth upgrading the brakes to the Brembo kits ( calliper, rotor, pads, brake lines)

I would love to convert to manual box but i think that will be issues. What do the guys do to the Auto box? Change clutches?

I wanted to get a Momo steering wheel fitted to.

I will get a mate of mine to do the mapping of the car.

 

To My XJR I have 100 cspi cats, stage 1 intake and flap mod.

I also have a 101 pump and pulley ready to go in
I'm working on a cold air duct for the flap mod as part of a upper and lower grill mod

Pick of the Cats are here, last post
Exhaust Manafold 4.2 S/C

Details on the progress for grill and air duct are here
Repoduction X358 Grill

You can search for the flap mod, 101 s/c coolant pump, stage1 intake and pulley. Lost of info here and on the UK site

Hope that helps
Cheers
34by151

 

Welcome to the forum Sulli! You have come to the right place.

Wow, lots of questions, let's go through them one by one...

Suspension

My advice would be to leave the air suspension in place. You can quite easily lower the car (see my post here https://www.jaguarforums.com/forum/x...ur-x350-75369/ )

If you are looking for further improvements, then a set of Polyurethane bushes throughout will help, and it's also possible to fit the sway bars / anti-roll bars from the last STR / XKR-S to the X350 (see here https://www.jaguarforums.com/forum/s...02-x350-94044/)

Lastly, if you really want to stiffen up the suspension, simply disconnect the CATS plugs from the shocks, and fit some resistors to the connectors, this will lock the shocks in firm mode, and the resistors will trick the suspension module into thinking that the shocks are still connected. There have been a couple of threads here on the forum which detail the size/rating of the resistors needed.

You could go for a set of coilovers from the S-Type, but I don't see the value in that, the air suspension has it's advtantages, and is height adjustable.

Exhaust

I know a bloke in Joburg, who used to have an X350 XJR, he completely removed the cats from his car & gained a hell of a lot of power (apparently there is no emissions testing in SA?) the way to get around the check engine light is keep the O2 sensors fitted, but put a mini-cat on the rear ones, which cleans the gas that the sensors measure. These are the ones he used. O2 Simulator Mini Cat Cel Fix best oxygen sensor simulator made.

A good free-flowing twin 2-1/2" system, minus the cats, is as good as you can get. There are no off-the-shelf extractors or headers available to suit our cars. https://www.jaguarforums.com/forum/g...-2l-s-c-80560/

Induction

First thing you need to buy is an Intake Elbow from Caldoofy (see here https://www.jaguarforums.com/forum/x...ailable-83959/ ) this is a must. Even better if you can ceramic coat it like 34by151 did. I have the older Qwiketz elbow on mine.

Jury is out on the filter. Some guys have fitted the Mina Gallery intake. I personally have just gone for a K&N flat panel filter, and removed the Wide Open Throttle flap from the airbox. Either way is an improvement over stock.

Pulley

There are typically two sizes of upper pulley available, the 3lb and the 1.5lb. The 1.5lb is smaller than stock, but does not need any machining of the supercharger snout to be fitted. It's supposedly gives around 1.5psi more boost. The 3lb pully gives around 3psi, but the snout of the supercharger needs machining in order to fit it, it as a lot smaller than stock. There are a number of suppliers out there, and you can get the pulleys in Stainless Steel or Aluminimum. I went for a Stainless one from Powerhouse in the UK. The pulley makes a big difference in mid range power & response, but overdriving the supercharger that much see's power flatten out or even drop off over 5000rpm. Don't bother with the lower pulley, it doesn't make much difference on the 4.2L cars.

Brakes

My XJR has the Brembos. I have not driven a later XJR with the Teves brakes, so I can't really compare. There are some aftermarket discs available for the Brembos (R1 Concepts, and EBC) and of course there are lots of aftermarket pad suppliers.

If you really want to go all the way, then you should know that the Alcon system with 400mm front discs & 6-piston calipers from the XKR-S are basically a direct bolt-in. The rears from the Alcon system as well. Even better if you go for the race-spec discs with floating hubs from Spires in the UK. However, it will not be cheap. I priced it up & the full conversion is around £5K in parts alone. You need to change the handbrake too. But if you want the ultimate, this is it.

Gearbox

Sadly, there is no aftermarket programming or tuning available for the ZF 6HP26 transmission in our cars (and believe me, i've tried to find it. https://www.jaguarforums.com/forum/g...ids-sdd-77299/)

The best you can do is go for a rebuild with new valves. There are a lot of heavy-duty parts available from the aftermarket in Australia, but you can't take advantage of them because of the lack of programming.

I was in contact with a bloke in South Australia who modifies the Torque Converter on the ZF transmissions in the Ford Falcons which reduces some of the torque losses, and does not require any special programming. He has not done a Jag one yet, but he thinks it will be possible.

A manual conversion is feasible from a mechanical point of view (using the gearbox, clutch, flywheel, bellhousing, shifter & pedals from the S-Type Manual Diesel) but the issue is re-programming the various modules in the XJR to accept a manual. There is a bloke in the UK called Norman Durban who is "working on it" but it will be while yet I think.

Other stuff

As far as I'm concerned, a Quaife LSD is a must. It completely transforms the car. Do it! https://www.jaguarforums.com/forum/s...e7/#post689345

34by151 already mentioned the Bosch 010 Intercooler Pump Upgrade, I've done this on mine, I believe it helps to bring the I/C temps down. Further from this you could go for a bigger I/C radiator, & a reservoir for the I/C circuit. The ultimate step for the I/C is to go for a refrigerated system i.e. Killer Chiller.

Another mod to think about is getting the throttle body bored out by Maxbore.com

And lastly, the Avos Twinscrew Conversion. https://www.jaguarforums.com/forum/p...xtra-hp-42059/ but the kit is not finished yet...get in touch with Avos, as this will be the ultimate mod for your XJR.

Momo Steering Wheel

Ummm....ok, if you want...

ECU Programming

This is the final frontier. There are very few people who will even look at doing the ECUs in our cars. The ECU is a Denso 32bit twin unit. One of the major problems we have is that the ECU will pull back the throttle once the torque output from the engine exceeds 600Nm. This is because the ZF transmission is rated for 600Nm and the car tries to protect itself by limiting power. I don't know if will be possible to remove these limitations or not. People are working on it behind the scenes, but it takes time.

So, there you go...some things to think about.

 

Cambo, Thanks bud, you talking in a logical point form that makes sense to me. I appreciate it as I can see you've taken the time to read my requests.

Suspension,
I have heard so many negatives on the air suspension. I drive my vehicles hard, and really push them to their limits on a regular basis.
I wanted hassle free, adjustable, reliable, stiff suspension. I don't mind a rigid ride.
Are there any other coil overs available such as koni ect... that you know of?

Exhaust;
In SA there are no real restrictions. So i will get one of my mates to manufacture one and get those mini Cats. They quite cool.

Induction;
I know there are pan K&N available that slot in the existent airbox. Are there no open cone filter set ups?
For Caldoofy's elbow, LOL, I will get one locally manufactured too. All the hoses ad clamps are available too.

Diff ratio's;
Bud I read the thread on the diff ratios and got heavily confused.
How did you get around the fault listing?


Gearbox;
Would you say that Jaguar have the power to re programme the Manual boxes should you fit one. Has any one contacted them to do it and what was the reason for declining?

Steering wheel;
LOL, The original steering is hideous!!!!!!! I dont have a good feel of it. My SRT8 had the best.

Thanks again for your assistance.

 

Thanks 34by151. I am going to compile a big list and get Cracking.

 

Does Someone have Norman Durban's Email address?

 

For what its worth here is my take on the Cats/Test Pipe

XJR 4.2 S/C OEM Cats
These are 2 cats in one housing
The First Cat is 400 Cspi and the Second is 600 Cspi
The Second O2 sensor is mounted between the 2 cats

So in terms of the sensor It sees a 400cspi cat
Now if you have lots of miles you will have carbon buildup in the cats.
If you are not getting a warning it is somewhere between new and failed, how blocked is not known
I mention this because if you install a 400cspi cat you will free up power but only to that when the cats were new

200CSPI Aftermarket Cats
These will flow more than the OEM cats and take longer to block up
You will be more sensitive to setting off the Mil light and may need a minicat but its more a test and see on that
As the holes in the cat are bigger you may pass an emissions test on gasses but if your test also includes particulate size you will fail due to the larger holes

100CSPI cats
These will flow more again
The restriction is minimal when compared to a test pipe. Every test I found in the net showed no difference in power between 100cspi and test pipes
You will fail an emissions test on both gasses and particulate size
I have not tested if the mill light will go off. I installed mine with a minicat from bigdaddies garage. Link in cambo's post

Decat
Here I refer to a gutted cat, IE removing the guts so it looks like the cat is installed
This will flow a little worse than the 100cspi cat unless you weld in a straight through pipe. In this case it will flow about the same
These are totally illegal in most countries/states
Most countries/states have big fines for removing the cats so beware

Test Pipe
There is little benefit over 100cspi cats in terms of flow
These are totally illegal in most countries/states
Most countries/states have big fines for removing the cats so beware

Test Pipe and Decat Detection
The testpipe is easily detected visually
The Decat is easily detected as it easy to spot the minicat (Police and emissions testers are not stupid!!!).
Cats also get very hot when they run so even if you hide the minicat inside an inferred temp gun will see the difference and yes the Police may have one in the car
Now here is the fines in OZ,
Failing emissions $400
Cat Removal (decat / testpipe) $10,000 + the $400 for the emission fail
There are no active tests here for rego but you can be pilled over and ordered to go for a test. The $400 fine is imposed if you fail test. However if you are caught with a testpipe the cat removal fine is on the spot.

So my advise is go the 100cspi and a minicat
Worst case you fail an emissions test and cop a small fine and are forced to swap in the OEM cats (for the test)
Now if you go the decat/testpipe you also cop a massive fine on top for cat removal
Given the 100cspi has a minimal difference its best to go with the 100cspi and minicats
You may get away without the minicats but for under 100 bucks for both delivered why bother

I went with 100cspi cats. Mine have a 3.5in body and 2.5in inlets/outlets with mincats
I reused the sensors and reset the adaptions

Cheers
34by151

 

Awesome writeup 34by151!

Sulli i've sent you NormanD's email address via forum email, hope it gets through.
Now regarding your follow up questions;

Suspension

Well, as it turns out, the lower mounts for the shocks are the same on the facelifted (post 2002) S-Type and the X350. Some people have actually fitted S-Type coilovers to X350's (example here https://www.jaguarforums.com/forum/x...version-79499/) BUT the top mount flange is not the same, and you have to drill new holes!

Some problems however...

1. The X350 weighs less than the S-Type, so the ride height comes out higher. You would need some height-adjustable coilovers, capable of dropping around 2 inches.

2. You will lose the CATS system altogether.

3. The ride height will no longer automatically adjust to vehicle load. Believe me this is the best aspect of the air suspension. I would miss this so badly...and it's one of the reasons why Jag went to air suspension. Imagine the car with 1/4 tank of fuel & just the driver (lightest) to a full tank, boot full of luggage and 5 people on board. That could be 700KG difference in weight (not fair from adding 50% to the overall weight of the car). The air suspension takes care of this. The coilovers dont...

My car has 161'000kms on it, with all four original air shocks still fitted. The original compressor was changed over at 150'000kms. That's pretty reliable! Touch wood, but it's only Americans who have problems with air shocks blowing out LOL

Exhaust

Lucky you. We have to run cats, as 34by151 explained.

Induction

Well for the price, I find the Caldoofy pipe good value. If you have the time/means/patience to do it yourself, that works too. For an open cone intake the only off-the-shelf solution at the moment is from Mina Gallery.

Diff Ratio

Well nothing happened. Nobody has been able to re-program the TCM in our transmissions. I asked everyone, including Jag themselves, ZF, SCT, and a number of transmission specialists. The idea at the moment is once NormanD has the electronics sorted for a manual conversion. Then use a standalone TCM to control the auto. This would also enable custom tuning. But it's a long way off...

Steering Wheel

I guess you have the half-wood/half-leather wheel? Mine had that, i didn't like it. So i fitted a full leather wheel from an S-Type R. Nice & chunky. The airbag is a straight swap, just need to change the plastic cover on the rear. If you are looking for an aftermarket wheel, then look for one to suit a 2002 onwards S-Type, they are interchangeable...

Cheers!