stuart adair

In a now famous bit of British TV, the Top Gear team took an old XJS V12 and
fitted a nitrous kit. They claimed that this increased the engine to 780 bhp
(And it certainly went like lightening) -
http://www.bbc.co.uk/topgear/prog13/nitrous.shtml

For my experience the weak bit of the whole set up is that rear diff and the
clutches inside, everything else is just nice thick steel - So I guess if
anything is going to break its these clutches. Try the earlier type of diff
(No speed sensor fitted to diff casing) as this is the traditional sort.

Stu


"marc" <null@null.null.null> wrote in message
news:2afn91dfaumeadpiggnc8g3um1d2tfbmgm@4ax.com...
> hi ,
> just looking for a irs system for a kitcar , It needs to be
> strong . I was wondering if anyone would know how much power a jag
> irs system would take before failing. Also which components tend to
> be the ones that fail.
>
> cheers Marc

marc

cheers for your reply . kit car will have a bored and stroked 351 ford
cleveland in it , roughly estimated torque figures are about 500ft lb.
So hopefully earlyish jag irs system will be strong enough. just one
other thing I have heard the later jags xj 40's have a altered setup.
Outboard breaks and a different lower wish bone. Any thoughts on this?

Marc

webserve

Marc,
If only you could combine the best of the two IRS systems!!
The XJ6 and the XJ40 systems are fairly similar in design, having re-built
both. The advantage to the XJ40 is that the hub and the brakes are outboard
making it FAR easier to change rotors and pads whilst everything is on the
car. The same operation on any XJ6 or XJS can be a nightmare with the
inboard system.
The problem with the XJ40 design is that the bearings on the stub axle
coming out of the differential are large diameter ball bearings.
Recommended average life is about 40,000 miles. They are a terrible weak
point. The XJ6 has roller or taper bearings which are much better performers
than the ball bearing type bearings of the XJ40.
The question you need to find out is if the spline for the 1/2 axle of
the XJ6 will fit into the hub of the XJ40. If they will match up, then you
can replace the XJ6 wheel hub with the one from the XJ40 and have outboard
brakes. Unfortunately, the stub axles have different bolt on patterns and
you can't swap one for the other at the differential end.
The other negative (or possibly a positive) about the XJ40 is that it
does not come in "cage" like the XJ6 and XJS. The differential and rear
suspension are anchored into a LARGE crossmember stretching nearly the width
of the car that bolts into the frame. I think it is actually a bit of a
better design, but that is personal opinion.
Here is a link to a website with photos of a cage removal from an XJS.
It will give you a good idea of what you are working.

Webserve



"marc" <null@null.null.null> wrote in message
news:j2ap919ff0t6fhv3alk141ek5sa59lemlu@4ax.com...
> cheers for your reply . kit car will have a bored and stroked 351 ford
> cleveland in it , roughly estimated torque figures are about 500ft lb.
> So hopefully earlyish jag irs system will be strong enough. just one
> other thing I have heard the later jags xj 40's have a altered setup.
> Outboard breaks and a different lower wish bone. Any thoughts on this?
>
> Marc

webserve

WHOOPS! Forgot the link!
http://neptune.spacebears.com/cars/stories/cage.html

Webserve


"marc" <null@null.null.null> wrote in message
news:j2ap919ff0t6fhv3alk141ek5sa59lemlu@4ax.com...
> cheers for your reply . kit car will have a bored and stroked 351 ford
> cleveland in it , roughly estimated torque figures are about 500ft lb.
> So hopefully earlyish jag irs system will be strong enough. just one
> other thing I have heard the later jags xj 40's have a altered setup.
> Outboard breaks and a different lower wish bone. Any thoughts on this?
>
> Marc