how to stengthen thr bulk head on a mk2 cav convertible

[mirpur]

i want to strengthen the bulk head on a cav mk2 convertible to run a let possible 400-500bhp, seems not to have had any problems on phase 3.5 but still want to strengthen the bulk head or anything else i should do
if i strengthen the bulk head what do i need to do, if its welding in plates where are the best areas and what shape would i cut the plates to as there isnt a kit out there for it

[Davey j]

It's worth checking some of the repair threads on astra-mk2. Common problem on them sadly and the rules will apply for any Vaux with a steering rack on the bulkhead.

[mirpur]

davey j you referring to the rack coming away from the bulkhead, any other things to look out for
ive been told i need to seam weld the engine bay, then maybe the whole shell and a triangulated strut brace to tie in the bulk head, not to sure wht that means but will look into it

[tonyo]

davey j you referring to the rack coming away from the bulkhead, any other things to look out for
ive been told i need to seam weld the engine bay, then maybe the whole shell and a triangulated strut brace to tie in the bulk head, not to sure wht that means but will look into it

To repeat what DaveyJ said, have a look over on Astra-mk2.com, bulkhead flex seems to be a real problem on the Mk2 Astra. I've had a good trawl around, as I've got a GTE convertible, and I think I'm going to have to do this at some point. On the Astra, it tends to be cracking coming out from the pedal box area, where the hole is punched through for the servo etc. That needs to be fixed, strengthened etc..

Some Mk2 owners have also put triangulation in from the chassis rails to the bulkhead, to try and minimise the movement from bulkhead to rail, which I fully intend to do on mine. Strut braces are (IMHO) a necessary evil (Don't like em', but can see the use). On mine, I have a lower fitted already, and an upper on the way.

You are dealing with a shell (if its anything like the Mk2 Astra), that is not the strongest in the world, is 20 years-ish old, and has had a lot of the structure taken out to make it convertible.

[mirpur]

how do you strengthen the servo area
triangular brace from chassis rail to bulk head do you have any pics mate, is it just a triangular meatl plate welded from chassis to bulk head, how thick should the metal be thats used for the triangular plates

[Vinci]

I was intending to strengthen this bit up as well, got some cracking noise coming from the door (on the 'gearbox side') Mine's a five door Astra MK2, also not the stiffest chassis... Have a plasma cutter, so I was thinking of making some really thick plates on the bulkhead and weld something like a little tube frame on that towards the front beams and brace them together well on the front where the radiator is. Mine is also not an original GTE, so I don't have the front beam connected there at all, only by the lower crossmember and the top... I've also understood the GTE is strengthened at the A-styles, also thinking of welding some bracing in that part, right now it feels like the cracking from the door is due to the whole nose of the car flexing on the rest of the chassis...

With the tube frame welded to the bulkhead I also like to brace the lower suspension arm mountings, there's not much stiffness over there at all and there's quite a lot of torque on that area....

[vectra640]

My mk2 cav suffered the same fate when I fitted power steering to it, it would eventually rip the bulkhead away from the inner wings because the rack would pull on the bulkhead and the wings wouldn't flex as much due to being welded to the rails, triangulation is a good option and definately strut braces