i wish the XJS section had a performance subsection.


anywho, ive got so much room to work to spare with my new engine, its almost a joke. i could fit another L67 sideways between the harmonic balancer and the radiator.

so i was derping around with the idea of a shock tower brace. has anyone seen an XJS shock tower brace? probably not since theres 0 room, but im certain theres someone out there who has done or made a brace for their DB7. anyone seen anything like this? should i try an Aston forum?

 

I have never seen one but you certainly could make one.

 

There isn't much point, as the crossmember takes all the stresses, not the body. Cars with those braces have suspension members mounted to the body shell, and need that support. On the Jag, the entire suspension unit is complete, and self bracing. But if it is just a cosmetic exercize, go for it.
The top shock mounts are the only part connected, and they don't put much stress there. My facelift car has what looks like threaded mounts for a crossmember on the towers though... would be super easy to make one, if there is room between the bottom of the hood, and the top cover of the motor.

Dave

 

You don't have shock towers on an XJS, per se.

I'm not sure it would add any benefit but you could tie the front ends of the current diagonal braces together with a tube and some rod ends. Sort of like the Monte Carlo bar used on early Mustangs.

Also, the late convertibles had subframe braces that might add some rigidity to a coupe.

 

would you happen to have any pics of that?

 

If I remember correctly, deant22's Gentleman Thug has a tower brace on it.

 

pic enclosed!!

it only connects the tops of the shocks where they meet the body sheet metal braces, which are seam welded to body, it did help some, with flex in the front section, and braces into the firewall.

it does not connect the springs towers! that are part of the subframe.

i'm thinking its better than nothing at all,its light weight tubing, 1 1/8".

did it a short while back, but been thinking about it for 10yrs,(i dont like to rush things),, hehe.

 

i like it. form = function in this case. i think it looks great and it looks pretty simple to fab up.

 

If you want a brace the HBE convertible front brace make a difference on the coupe. Also diagonal bracing from the top rail to the bottom A pillar. I was surprised at how far the front of my drooped when I removed the front guards (fenders for Americans). With jack stands under the front jack points the nose of the car dropped over 1".

You might want to consider a rear subframe brace if you are putting 400hp+ on the ground.

 

I assumed you wanted it to "look cool". A shock tower brace on a double a-arm suspension does nothing. The reason they use them on your GM cars is they have a MacPherson strut front suspension so the geometry can't change due to flexing. The shocks in front of the XJS are only shocks and even if they did flex a bit it is of no real concern as they will still do their job.

 

thanks for the heads up. i didnt know anything about grand prixs until just now......

 

good idea for rear subframe bracing, i added them to mine 16yrs ago, with adjustable Hiem joints.

for some who may not be aware, with enough off the line torque, and good grip tires,you can rip the whole rear frame loose from the body,especially if there is rust in the areas holding it in! when you jack it up by the body the whole thing drops out on the ground,HEHE.

XJ Jags were never made to have a hard launch, from a standstill,( now wouldnt it look kool lifting the front wheels on an XJS).

most serious performance guys mount both front and rear subs solid,reducing flex even
more. and arent interested in NVH. i have some pix of the 1977 Group44 cars with that mod, some old crap i'v had for years!

also MANY good race cars with double A-arms, uppers and lowers ,run whats called a Bay bar, it connects the engine bay top roll bars together,for ridgity.
most are bolt in, so as to remove bar to remove the engine.