Thanks for the detailed explanation Cambo, guess I should have bought a car with VVT...

Very interested to see how your tune works out. Very frustrated how difficult these cars are to modify compared to the competition!

My trap speeds average around 105mph and best so far 107mph since the new cats.

 

Jackra, Here is an option for us Americans! I'm going to call them today and get some stats.... Jaguar | ECU Tuning Group

 

Good luck viper1996. Just got back from 2 weeks in UK so catching up.

 

ECU tuning specializes in Ferrari, Lambo, Bentley, and Bugatti tunes to name a few...These are real tunes custom mapped to make real HP...Unfortunatly the XJR tune is for 2006 and up...I talked to Jags the resident expert there and he said the 04 and 05 use a different ECU which is different from 2006 and up...An older platform...But he did say he believes he will be able to crack into the ECU with some older software and get the tune installed properly...The tune is designed to work with a 1.5 lb pulley...
He also stated that there tune with the pulley is good for 50WHP on the VERY conservative side and fuel economy will improve...He also stated the base factory ECU tune is pig rich, and that is why there tune with pulley pickup so much HP...Lots of room for timing advance and leaning it out I guess...They tune worldwide on all sorts of high end exotics and I do believe his claims about the XJR...

 

Exactly what I said a few posts back...

Not via the OBD port, the pcm has to be removed from the car and flashed on the bench.

LOL!!!

On a >2006 with vvt, maybe... Possibly... but not a chance on a 2003-2005 car... not a hope...

Go and have a look for the STR here on the forum that was tuned, it didn't even make 10hp more...

 

Hmmm...Then what's the answer Cambo? I don't want to spend 1400$ for 10 HP...I find it hard to believe claims of a Caldoofy that adds 10 HP, but a tune designed to work with a 1.5 lb pulley. pulling fuel and adding timing will not surpass an intake......Do you have a link to that thread? Or should I just do an intake, K&N, airbox mod and call it a day?

 

Here's that thread https://www.jaguarforums.com/forum/s...e4/#post833715

 

Is $1,400 what ECU Tuning Group charges?

 

Yes with a 1.5 lb pulley installed by them...Or you can install it yourself prob save 200 in labor maybe...Cambo has a great point...The o4 and o5 do not have VVT therefore the tune they sell would not be correct for these years...And they have to bench flash the tune, so it would be a totally incorrect setup for the o4 and o5s,...Looks like your car would be the right candidate to do utilize there tune...

 

Or ask cambo for his tune as, from talking to him, I think he is ticking all the right boxes in terms of understanding the jaguar system eg raising the torque limit on the trans ( this limit restricts Max gains on these cars).

 

Well yes to be absolutely clear.

The 2003-2005 cars do not have VVT, and run a Denso 32-bit PCM which is totally different to the 2006MY onward cars with VVT. Actually the PCM in the later cars is greatly improved in capability, as well as accessibility.

The 2003-2005 cars have not responded well to tunes as you can see on that STR. Why? See my previous comments regarding the VVT and changing the cam timing.

Just because a company says they have a tune for a 4.2 supercharged Jag, does not mean they can tune a 2003-2005 XJR, STR or XKR, or get the big numbers out of it like the 2006MY onward cars...

NOBODY can tune a 2003-2005 model via the OBD port, they all have to pull the PCM apart and bench flash it. We are getting closer to having a tune that goes in over the OBD port, but it's far more complicated than the later cars...

Thanks John.

Yes in the process of trying to sort out a tune for the early 4.2 cars, we were able to get a tune for the 2006MY onward cars sorted that can be flashed with IDS/SDD. It's been tested in an XJR but only ****-dyno results so far.

 

ETG claiming 50rwhp from a tune and pulley on a 2003-2005 XJR or STR made me laugh too! You think they'd post some dyno charts for a $1400 tune but I don't wonder why they don't anymore. Viper, tell Jags you want to test the tune on an independent dyno and if it makes the numbers claimed you'll pay. I'm sure it would be good business for him too if he believes what he told you. This thread shows how much more power the VVT cars with the more accessible ECU can make - about 400rwhp with pulley, tune and cats on the 4.2 XF SV8 https://www.jaguarforums.com/forum/x...result-141962/

In comparison, the highest 2003-2005 R's (without TS) I've seen are ~360rwhp. Like Cambo says, on the older non-VVT cars you need to remove the ecu for bench tuning using a K-tag and the gains aren't as big. We can hope for 20rwhp realistically and there's two suppliers I know of that can do this now, although expensively - Rica Tuning in the Netherlands or Tom Lenthall in the UK.

Failing that there's the option of a programmable MAF (like Pro-M or Abaco) which you can adjust the fueling tables yourself if you know how to tune. I think one of these larger MAFs with a larger, revised inlet tract from the SC inlet, with a ported TB to the airbox would be a better way to spend $1400 imo.

 

Im going to contact Tom Lenthall to see if they have a proper tune designed for the 04 and 05 models designed to work with there pulley...By then maybe Cambo will have his tune up and running and he can sell it to us!

 

That's definitely a good place to start if you're happy to remove your ECU and send to UK. If you do go down that route, make sure to dyno to see what you gained.

 

The reason we (well actually, my ex-JLR contact) is trying so hard to develop a tune for the 2003-2005 cars that can be flashed over the OBD port is to avoid having to remove the ECU and send it away.

The time, expense and risks involved in bench flashing make it unappealing in my eyes. It's a PITA to get the ECU out (remove the wipers, scuttle, cabin filter, etc) then you need the special 5-point torx bit, and car is immobilised while the ECU is away.

And then there's the shipping time & expense of sending the ECU back & forth, from the US to the UK? Will someone really do that?

And lastly what happens when you get it back and something is wrong, car won't start etc...

The ECU's in the 2003-2005 cars are really unfriendly things, believe me... my contact has been working on this for quite some time now and it's been a real eye-opener.

The later Denso ECU's are a real walk in the park and it was not an issue to make a tune for them that went in with IDS/SDD like a factory file. But the earlier ones are a totally different unit so most of what was learnt from the later versions went out the window...

But he had a breakthrough just yesterday actually, so we are getting closer...

 

So I am purchasing 200 cel cats from Paramount. It will take a while as they appear to fabricate to order. The exchange rate is at something like a 30 year low so I am taking advantage of that plus they are giving me a break on shipping.

I want bolt on so that I can return to stock easily.

This gives me motivation to reinstall my rebuilt SC as I was not feeling very motivated to say the least. I am still jet lagged from coming back from the UK!

I have to drain the coolant anyway to replace a leaking hose that comes up from the aux pump.

 

This is interesting.

The person I am conversing with, at Paramount, insists that they can tune an ECU on a Jaguar XJR 2005.

I asked them to double check and stated that everyone else I had contacted told me that they could/would not touch pre 2006 models.

They say that it is a home tune device and that it is 50/50 whether or not it will read the ECU. If it does not work they will refund everything.

They would also do a bench flash but of course as Cambo stated it is a lot of work to get the ECU out and then shipping costs.
BUT if it does not work do I end up with a bricked ECU? I also do not know the price yet.

 

50/50 chances? That sounds encouraging! (not really, they don't even know what they can do????)

They are probably getting confused between model year and the year the car was built or registered.

In the UK they talk about the registration plate as the year of the cars, as in an 05 or 55 plate, because the car was built or first registered in 2005, but most of those cars are actually a 2006 model year.

Like my XJR is a 2005 model year vehicle, but it was built in April 2004 and was registered in the UK on an 04 plate. Most Brits consider it a 2004 but the actual vehicle specification is 2005MY.

Ditto for them saying they can tune a "2005" XJR they are probably thinking 05/55 plate, which is actually 2006MY.

My advice, don't waste your time on it... unless your XJR has a VIN higher than G49071???

EDIT

Nevermind, I just checked the pictures of your car in your gallery, yours is a 2005MY for sure...

 

My build year is 2004. Forget what month of the top of my head.
Agree 50/50 chance of success is a no go anyway.

 

Is it because the earlier (2003-4 etc) cars use the Denso with two cpus inside whereas the later ones have a single but much faster cpu?