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Jaguar XKR Portfolio - the poor mans Aston

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  • Nugs
    replied
    Originally posted by Jack Nicholson View Post

    Nugs it's a charcoal interior, same as your dads
    Nice, his is still being used regularly, but not racking up many kms, I think it's up to 35,000kms now.
    Only thing that has gone wrong with it is the headliner sagging.

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  • GAZ914
    replied
    Excellent!

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  • biteme
    replied
    Good work on finally making progress with making the Jag fast

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  • Jim
    replied
    Mate that’s fucking awesome and deeply nerdy.
    good stuff!

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  • landbarge
    replied
    Down the rabbit hole I go...
    Cheers.

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  • Jack Nicholson
    replied
    Originally posted by landbarge View Post
    I can't watch the vids in either of those links. Any ideas what I can do to see them?

    Sent from my CPH2005 using Tapatalk
    Tapatalk is borked. Doesn't display entire posts, and doesn't show the vids, you need to use a regular browser.

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  • landbarge
    replied
    I can't watch the vids in either of those links. Any ideas what I can do to see them?

    Sent from my CPH2005 using Tapatalk

    Leave a comment:


  • Jack Nicholson
    replied
    Yesterday was the 4 year anniversary of this car coming into my possession.

    And it was almost exactly 3 years ago that it "set the record" on the 1/4 mile, with the 12.46 @ 115mph
    https://performanceforums.com/forums...73#post6365373

    At the time, that was all we were going to get. And despite making lots of other peoples cars faster, there was nothing more to be had from mine.

    Until earlier this year, when the Russians cracked the factory programming in the JLR ZF transmissions.

    But of course, nothing is simple with these cars, and it turns out the calibration & strategy in the 6HP26 in the 4.2L X150 is unique, in fact very different to all the other JLR models.
    So despite learning lots from other models, it turned out we were back to square one with tuning the trans in this car. And even "better" back to square one on the engine tune too.

    Without going into minute nerdy detail, the old engine tune had a lot of "wrong" data in it, to get around some torque limiters in the transmission.
    e.g. putting offsets on a whole heap of data, so that while the engine was actually making >600Nm of torque, all the calculations were giving an answer of 550Nm.
    So the TCM wouldn't command a torque reduction (that's not exactly how it was, but that's just to give you the idea).

    Now with the tune in the TCM able to be modified, so those limiters were adjusted, and then we realised that the TCM and PCM were no longer co-operating, because of the incorrect data.
    So the engine tune (in the PCM) had to be re-done from scratch, with real numbers....

    Six revisions to the engine tune, and nine revisions to the transmission tune later, it was coming together.
    I'd been to the track a few times, and lost count of how many nights out on the road testing these revisions.

    Found a few more issues as well, like the Traction Control (DSC) was still commanding torque reductions and short-shifting, even with the DSC turned off.
    This was a real head-scratcher, as none of the other Jaguar or Land Rover 6HP had this in the strategy.
    Eventually Nick the tuner found the same shit in the TCM from the Ford Falcon, which helped to find it in the Jag, bad news we can't turn it off completely, but it has been dulled a little.

    So we got it to the point to go back to the track & have a proper crack at it. I bought a Dragy as well to get the 0-60mph numbers too.

    And then it started raining. Race4Real got rained out 3 weeks in a row, Sunday Session got rained out...

    And then the Covid outbreak in Sydney... And here we are, seems doubtful i'll be getting back to the track in the next few months.

    Fuck it...

    So what's the difference with the transmission tune?

    Well the shifts are faster, and more aggressive, but I don't think that's really making much difference to the ET...

    The main difference now is how you launch the car.

    In the past the best 60ft's came from just sitting on the line idling, side-stepping the brake as you smashed the throttle.
    Loading it up on the line would trigger a torque limiter, and it'd actually be slower.
    Now you can stall it up a little, and launch harder, but it's a fine line between getting away cleanly, & just spinning em.

    The 60ft on my 12.46 run 3 years ago was 1.959, now i've got it down to 1.793

    During the last round of testing before the rains & lockdowns, the car weighed in about 40kg heavier than 3 years ago too.
    That was due to running a half tank of fuel (used to always run around a quarter) and because i've become an even fatter cunt than I was three years ago...
    The mph was down a bit compared to three years ago, i'm putting that down to the weight...

    Anyhow... I got a couple of 12.1's in, with a little weight loss a 12.0 would be in reach, with a skinny cunt driving, 11.9's...

    Click image for larger version  Name:	IMG_2580.jpg Views:	0 Size:	2.34 MB ID:	7274753

    And here's me being handed my arse by a Commodore...



    In the meantime, i've decided to cut down on the booze & shit food, 'cause I need to drop a few kg...
    Last edited by Jack Nicholson; 25-07-21, 05:02 PM.

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  • Bren
    replied
    Yeah that was a great watch. Bit of an eye opener.

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  • schnitzelburger
    replied
    interesting, i didnt know any of this about AM

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  • Jack Nicholson
    replied


    I had to LOL at 5.28 , given the title of this thread.

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  • Jack Nicholson
    replied
    I got a phone call today, totally out of the blue, from another 2009 XKR Portfolio owner.

    He sent some pics.



    Even stranger, he has the same name as my dad... that was quite a laugh.

    I suspect I'll be seeing this car in the flesh sooner rather than later.

    /csh

    Nugs it's a charcoal interior, same as your dads
    Last edited by Jack Nicholson; 27-05-21, 07:58 PM.

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  • Jack Nicholson
    replied
    Cheers kents, gotta say i laughed my arse off when I opened the mail that day.

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  • Bren
    replied
    That's awesome, good one mate!

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  • THE CHIEF
    replied
    Good job chap.

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