Strengthening the Cerb Chassis

[roseytvr]

Well at last some real progress:



I have almost finished stripping the chassis so its close to going off for blasting/painting shortly. I am thinking what improvements I can make to the chassis before its painting and have search for chassis strengthening to no avail. Has anyone any recommendations or links to info on strengthening the chassis?
Cheers
Ian

[gruffalo]

Putting some webbing where the rear ARB mounting arms meet the main chassis is worthwhile, not much else can be done easily.

[Tanguero]

Putting steel in so that the passenger seat is bolted to metal rather than plastic, also so the front of the drivers seat is through steel as well!

[plasticman]

On my cerbera I welded tubes from the shocker plates too the front outrigger to triangulate that section with a fillet beween the diagobal and horizontal outriggers to spread the load . You can then add a bracket to put the top wishbone bolt into double shear .

[Byker28i]

Tanguero said:

Putting steel in so that the passenger seat is bolted to metal rather than plastic, also so the front of the drivers seat is through steel as well!

This - worthwhile task

[mk1fan]

Engineer1949 Cerb build thread would be worth a read.

I also agree about adding connection plates for the front seats.

[billybradshaw]

Byker28i said:

Tanguero said:

Putting steel in so that the passenger seat is bolted to metal rather than plastic, also so the front of the drivers seat is through steel as well!

This - worthwhile task

Evening gents,

What is the approach to doing this? Is it a body off job or in situ? Any fibreglass work associated with it?

If anybody has any pics I would appreciate it if you could post them so I can have a shufty.

At

Ian

[Tanguero]

billybradshaw said:

Byker28i said:

Tanguero said:

Putting steel in so that the passenger seat is bolted to metal rather than plastic, also so the front of the drivers seat is through steel as well!

This - worthwhile task

Evening gents,

What is the approach to doing this? Is it a body off job or in situ? Any fibreglass work associated with it?

If anybody has any pics I would appreciate it if you could post them so I can have a shufty.

At

Ian

I know it has been attempted without taking the body off but that suffers the same drawback as the much argued option of replacing outriggers without taking the body off - that you cant possibly powdercoat/paint over the new welds.

Be that as it may, my method was definitely body off only as it involves strips of steel welded to the centre outrigger support that are shaped to fit in the channels in the floorpan and run front to back. The other technique I have seen attempted is a bar running across the car between the outrigger and chassis main rail. I couldn't find a good way of making that fit the floopan without reducing the ground clearance hence my version.

[jamieduff1981]

plasticman said:

On my cerbera I welded tubes from the shocker plates too the front outrigger to triangulate that section with a fillet beween the diagobal and horizontal outriggers to spread the load . You can then add a bracket to put the top wishbone bolt into double shear .

Do the extra tubes cause any (additional) limit on steering lock or is sufficient clearance maintained? (My chassis is due an overhaul, so I'm particularly interested)

[plasticman]

I use the wheel on full lock and droop to position the tube which means it cannot go to the corner where the out rigger meets the sill unfortunatley.I have just made some steering arms that add ackerman into the steering but now cannot be used on this car because of the diagonal being to close to the tyre. As you can see in the photo I have also strengthened the wishbone plates which are a definate week point.

[FarmyardPants]

Tanguero said:

I know it has been attempted without taking the body off but that suffers the same drawback as the much argued option of replacing outriggers without taking the body off - that you cant possibly powdercoat/paint over the new welds.

Be that as it may, my method was definitely body off only as it involves strips of steel welded to the centre outrigger support that are shaped to fit in the channels in the floorpan and run front to back. The other technique I have seen attempted is a bar running across the car between the outrigger and chassis main rail. I couldn't find a good way of making that fit the floopan without reducing the ground clearance hence my version.

As much as I think the current seat support is crap, and anything to rectify that is an improvement, those supports look a bit weedy if you don't mind me saying?

[Jhonno]

FarmyardPants said:

Tanguero said:

I know it has been attempted without taking the body off but that suffers the same drawback as the much argued option of replacing outriggers without taking the body off - that you cant possibly powdercoat/paint over the new welds.

Be that as it may, my method was definitely body off only as it involves strips of steel welded to the centre outrigger support that are shaped to fit in the channels in the floorpan and run front to back. The other technique I have seen attempted is a bar running across the car between the outrigger and chassis main rail. I couldn't find a good way of making that fit the floopan without reducing the ground clearance hence my version.

As much as I think the current seat support is crap, and anything to rectify that is an improvement, those supports look a bit weedy if you don't mind me saying?

I think the idea is more that you can now bolt up to metal, rather than direct to fibreglass, and you now have to try and tear the strip through the floorpan rather than just the washer.

[mk1fan]

I'll be installing strips between the outrigger and the bottom [centre] rail on both my S's so that the seats are structurally fixed. This is possible on the S chassis / body. Cerb may have stuff in the way.

[plasticman]

All I have been doing pretty well since the eighties is repairing and modifying TVRs and am yet to see one where the seat has ripped through the fibreglass floor. It is different on the speed six cars because the seat belt is mounted to the seat so require a much stronger mounting .
The issues I am addressing are where the chassis flex even in normal driving.

[mk1fan]

I have Elise seats in my S.

[Tanguero]

Jhonno said:

FarmyardPants said:

Tanguero said:

I know it has been attempted without taking the body off but that suffers the same drawback as the much argued option of replacing outriggers without taking the body off - that you cant possibly powdercoat/paint over the new welds.

Be that as it may, my method was definitely body off only as it involves strips of steel welded to the centre outrigger support that are shaped to fit in the channels in the floorpan and run front to back. The other technique I have seen attempted is a bar running across the car between the outrigger and chassis main rail. I couldn't find a good way of making that fit the floopan without reducing the ground clearance hence my version.

As much as I think the current seat support is crap, and anything to rectify that is an improvement, those supports look a bit weedy if you don't mind me saying?

I think the idea is more that you can now bolt up to metal, rather than direct to fibreglass, and you now have to try and tear the strip through the floorpan rather than just the washer.

Exactly this! Rather than simply pull a washer through fibreglass - the entire bar of 8mm steel would have to tear through and even then the seat wouldn't come loose as they are very solidly welded to the centre support. Given that there isn't any particular history that I could find of seats tearing loose in accidents I am happy that it is a good compromise given the shape of the Cerbera floor and in any case about 10,000% better than a penny washer through fibreglass.

[FarmyardPants]

Ah, I see. I'm with you now.