Manual 400bhp xjs v12 project

[deant222]

Hi,

This site has been an inspiration to me as I am about to
embark on a huge 'ground up', bare metal modernisation on my
1988 xjs convertible. I have been thinking a lot about the
parameters of this project with my pride and joy and I
wanted to ask you a couple of questions as to what is
possible. I want to take it up to about 450bhp naturally
aspirated and convert it to manual (I want it to feel more
like a sports car and very responsive (think DB7). Am I
barking up the wrong tree?

what would we have to do to the suspension / bushes &
steering? I want it to feel tighter and like a sports car,
but not a ‘boneshaker’ (I have previously had a TVR Griffith
and although I loved it, I am a much older guy now / feel
the pain more).
What are the big BHP gains one would have to do to the
engine? Again, I don’t want it to run like a ‘Hooligan Rover
V8” (a good ‘growl’ is wholly acceptable). I am looking for
the easy wins here. I have a great restorer here in NZ, but
he is unsure on the suspensions specs and the V12 engine.

The key is the suspension and Steering. what do you guys
recommend?

i have seen the pages on the 600bhp xjs, but this is not the
effect I am after. I am looking for a daily driver that just
happens to have heaps of power under the hood, when it is
called upon. To the normal eye it is just a beautifully
restored XJS.

I have a full powerpoint visual brief if anybody is
interested further in this. The project is well funded and
ready to go, just keen to make sure the best solutions are
implemented.
Dean

[a8hex]

I would think body stiffness would be a big issue on the earlier convertibles. The post Ford acquisition cars are supposed to be much stiffer. It might be worth trying to find out what Jaguar did with the later cars to improve this.

Power shouldn't be an issue, those numbers seem fairly modest.

I know they guy who works on my Jaguars has done manual conversions, there seem to be plenty about. I wonder whether there has been a write up of the process in one of the club mags or in Jaguar World.

[Kevin VRs]

I might be mistaken (I hope so) but I seem to remember reading an article some years ago that reckoned it was very difficult to get the 5.3 to more than about 330bhp without major/expensive work.

[JTXenon]

What's happening with this? It sounds interesting

[oldboyswithtoys]

i worked on jaguar for 15 years and now work on aston pm me if u need any help on the suspension side of things