Hey Avos;

Let me know and we can talk some more about the Twin Screw update as well, that I wrote you about,...I am looking for 500HP and it would be nice to know how much more, if any, remapping would add to the base 390/400 HP before we went to the SC change over.

thanks,

jj

 

Haven't you received my response 28/10?

 

Avos;

Yes I have it.

"it would be nice to know how much more, if any, remapping would add to the base 390/400 HP before we went to the SC change over."

Any ideas on that question?

Also I think you indicated in your email that the basic SC conversion would end up short of 500HP and I wonder what other tweaks you have up your sleeve that would get to that figure....just to keep the new XKR's honest...if you know what I mean.

cheers and thanks,

jj

 

The is much diiference between individual XKRs as well.
Some are just quicker than others.
My 4.0 is quicker than any other xkr I have driven so far.
0-60 is well below 5 seconds.

So remmappiNg and doing cooling mods and pulley mods also depends very much on the condition of the engine and the entire car.

Anyway, why dont you first start with the cooling mods an pulley upgrade to start with as that has to happen anyway to get decent results

 

Quote:

Originally Posted by jamjax

Avos;"it would be nice to know how much more, if any, remapping would add to the base 390/400 HP before we went to the SC change over."

About 25 HP max I would say. My advise to only do this if you are sure not to make other mods, this should be the last one on the list.

Quote:

Originally Posted by jamjax

Avos;Also I think you indicated in your email that the basic SC conversion would end up short of 500HP and I wonder what other tweaks you have up your sleeve that would get to that figure....just to keep the new XKR's honest...if you know what I mean.

No no, I said "about 500 rwhp" for the Stage II, rwhp means Rear Wheel HP. This is about 600 HP.

 

Avos;

We only talked about stage 1 upgrade not stage 2.

Do you mean the remapping should be last or that changing the SC should be last?

cheers,

jc

 

The part with the 500 rwhp was for the Stage II in the mail. What I mentioned about the Stage I, is that 500 HP (430 rwhp) is more the starting point. You can get much higher with simple cheap pulley changes (not the expensive Eaton ones), but at a certain point you are better off going to the Stage II version if you want more power for the reasons mentioned in the mail.

You can remap any time if money is not an issue, if the latter needs to be wisely spend, then do it last regardless of what supercharger you have.

So far I haven't even remapped mine; I probably will one day once I will settle for a certain setup. A good remap is not cheap, you need a good dyno, understanding of what you are doing, and time to get the performance and safety right.

 

Thanks Avos.

Do you happen to have a download of the Jaguar Monthly Article from May 2010 that you could send me?

It looks like that is your car on the cover, yes?

cheers,

jj

 

Thats Normans XK... click HERE if you want a read

 

Thanks Racer, you are a Prince.

Did you see my post that Viezu is not doing the XKR remapping/delimiting now?

Know anyone else or a dealer that would do delimiting work?

I have been meaning to ask you what the source of the "squirrely" was on your high speed track run, handling, front end lift, lack of rear end down force, track/road imperfections or trees?

cheers,

jj

 

Yes I did see your post about Viezu about not doing the later cars, I know they stopped the earlier 4.0ltrs but thought they were still mapping the 4.2s

I must admit I am assuming you have a 4.2 but 2003 was the change over year so you could well have a 4.0

I would not of thought a dealer could delimit the car, most places have WDS or the later some might even still have the old IDS but I did not think any of these could get you into the 'software' of the ECU to change the parameters in that respect

Getting back to squirrels....... The Milbrook bowl has numbers written in the road the top IIFC is 100mph the idea being when you reach that speed you can take your hands off the wheel and the car drives itself...... And yes it does, was a bit nerve racking but interesting, when you go well over the 100mph mark you need to remember we was on a round circuit and basically the back started to let go, for the untrained it would definately of been a 'brown trouser' moment, luckily I was not driving.

I have heard stories of guys with moderately tuned XKRs hitting 190mph, never seen or experienced it but willing to try

 

Thanks Racer,

It is a 4.2 and according to the VIN number (SAJAC42R643A37223) it is about 500 cars into the 2004 Model Year, though it was sold in July, 2003.

I will give the suggested number 4 fuse a pull and see if that takes out the Speedo which will indicate that the ECM control feedback from the wheel and DSC sensors are off line as well.

I meant to ask you what kind of limited slip differential the 2003 XKR has because I have seen several members, Avos and I think Rev. Sam, list in their modifications that they have added a limited slip differential.

In my naivete I just assumed most modern cars had that as a standard feature.

Also does anyone happen to know the dimensions of the boot/trunk of a 2003 XKR?

A friend wants me to bring back a 90cm by 70cm flat stained glass window from London....I figured there was enough room in either the trunk or the back seat for something that size....but now I wonder.

PS Will the Vin number tell me the options this car has? Sport seats for instance? It has the 20 inch Montreal wheels and Brembo brakes and I assume the 6 speed transmission.

PPS WDS and IDS sound like some kind of weapon system, which is to say I don't know what they are or why that would limit or in my case not de-limit the 155MPH limit in the software.

But looking forward to picking the car up in Richmond next Friday. Yeah!!

cheers,

jj

 

No steel bodied XK8/R has LSDs, although some might call the electronical braking from a slipping wheel a cheap man’s LSD ;-).

There are 4 options, a Quaife ATB, custom clutch one from Gripper diffs, OS Giken TCD clutch type (or NEO, but would opt for the TCD) and last but not least OEM LSDs from Jaguar from before 1997, which are also clutch versions.

Coming back the original question, I will also tune (/take of speed limiter) the 2005 XKR I was referring to in the mail and will do this together with a well-known Dutch Volvo tuning company which I guess you might know (have already done some work with them on our Jaguar ECUs).

 

Thanks Avos!

If this is how much you know/work on your hobby, I would hate to have to compete with you in your day job or come to think on it your hobby for that matter.

It is a 2003 XKR not a 2005 hope that doesn't change your mind about working on it.

You intrigue me about the Volvo Tuners because it makes me wonder if they have anything for my '98 V70R?

No I have not heard about the Dutch Tuners before.

Any info on them or articles?

cheers,

jj

 

RICA Engineering - Performance and Economy Tuning - Specialists in Volvo Tuning, BMW, Audi, VW, Jaguar, Mercedes and most other makes and models

 

Risky exceeding 155 in a convertible, the roofs not rated beyond that speed :-/

 

Up or down?

Never heard anything before this that there was a max speed rating for the convertible top.

cheers,

jj

 

Good to know, next time will have the roof down then ;-)

 

There is probably a speed rating on toupees and hair implants as well, and I doubt if it is 155 mph.

 

UP, jeeze 155mph with the roof down would see hair and folicles left well behind I would imagine (certainly in std guise with no deflectors.
I don't know of 'official' rating but I do know that Jag only tested the convertible roof to around 155 closed, less in the wind tunnel, the circuit test hit the 155 limiter but no car was ever ran for testing any convertible without the limiter in place (press tester in the family).
Could be very bad indeed if the roof fails at high speed, lots of noise, de-stabilisation and the sudden shock (to the driver).
I'd say if you want quicker than 155 go hardtop, but them I'm a wuss with anything convertible (as a result of several past hardtop rolls racing).