That is freekishly quick for a heavy NA car .
Very impressive !

 

Thanks Datsport

We're getting very close to our goal now the diff and headers should get us over the line

 

steve,

can you detail the build bits and software for those of us that would like to follow your lead? a 13 second car is no slouch!

 

Sure thing

*100 cell cats (Standard are 400 first stage into 600 cell ..very restrictive)

*x-pipe mid pipe (We just had some bespoke mid pipe systems made up yet to fit, currently running a simple x-pipe on standard system in place of resonator)

*XKR rear box (Doubt this adds any power but there for visual enhancement)

*Cooler spark plugs to allow for further advancement in timing NGK IFR7N-10 (C2C41805)

*ECM calibrated by Old Jaguar Performance

This particular combo will easily get the n/a into the 13s with a few more exhaust tweaks and some other mods I'm looking to perform I have no doubt I will be able to bring my 13.72et down to a 13.5

 

Here's the bespoke exhausts Steve is talking about;



I have one of these on my XKR now.

The tune that's in Steve's car could be flashed to any 4.2 X150 XK using an SDD diagnostic system (a proper one, not Chinese clone hacked junk).

It won't ever throw a P0420/P0430 code or check engine light because of the cats, that's been solved, as well as the improved spark, fuelling, torque limiters raised and so on.

 

is that x=pipe available at a specific vendor? is it very loud compared to stock?

steve, in the list of mods you cite, is there a sequence to perform? in other words, if I wanted to do the mods one at a time, what would you recommend first, second...?

 

Pete, for the center section there are a few vendors with it: or look up a local race exhaust fabrication place and have them make something.

I would just do it all in one step, doing it in stages is just taking things apart and putting them back together multiple times.

https://www.spires-st.com/product/xk...age-1-exhaust/

https://www.adamesh.co.uk/jaguar-xk-...tem-4324-p.asp

 

I had a quantity of the exhausts made in Sydney by an exhaust specialist who has a CNC bender, this was cheaper than buying them in from overseas, purely because of shipping something big & bulky costing just as much as the exhaust itself.

If you change the exhaust and the cats together, then yes it is much louder than stock, changing the exhaust and leaving the original cats is not too much louder.

 

Pete go the x-pipe and cats first followed by the plugs & tune

We can get a price for you in regards to the bespoke mid-pipe just unsure how much postage to the U.S would be

With the tune PM either me or Cambo and we can get you set-up

 

Just so I understand this post the net is all about bragging rights. Correct?

 

So was the landing of man on the moon...

We coulda developed and sent robotic probes instead.

 

Somehow I don't think anyone could send a man to the moon but anyone can get a car to run 13 sec 1/4 mile runs. Don't see the comparison. Just sayin

 

Sorry if this particular post offends you, unfortunately not everyone on this forum owns a 5l xkr which has no needs for further go fast mods .

Let's try and kept criticism constructive

 

Steve it doesn't offend me I was just asking if this was for bragging rights. That's all , nothing more. How others want to spend their money and time is up to them I was just trying to sort out the logic. I've found with cars there is always a faster ,more powerful, more expensive , better looking ones out there.

Enjoy the ride.

 

I think Steve is just sharing should others want to follow the path of modding an XK.

 

There is no logic required . especially when someone wants there car to be
custom , just do it .
its just a bonus that there are results in this instance.
and i think results that are well worth sharing .
did yo see its damn near as quick as a stock 4.2 SC ?
that is worth bragging about .

ill bet steve is enjoying the ride , in his ''faster than any one else's 4.2 XK8.
keep the bragging up thanks steve .











'

 

Thanks Jagtoes

Im not into this for bragging rights, I simply wanted to improve the performance of my XK with a methodical approach it just so happens that the fruits of my continuous research is finally starting to pay off !

 

Thanks for the support Datsports

Finding with the suspension upgrade and increased power the XK is a much better balanced machine now

Have a few more ideas in mind to get it closer to that low to mid 13 mark... perseverance is the name of the game with the n/a engine.

 

Tinkering with cars keeps folks from creating threads with this title.

 

Yep ranch but then again my motor is bigger then yours , LOL