Finishing welding?
 

Hey all

At what point in the chassis build is it potentially safe to finish off some of the welding?

The reason I ask is that as I am using an MX5 motor and box there is limited info on mounting and therefore tunnel dimensions etc. I will very soon need to move the chassis off the build table and over the engine to see where the clearance issues are but am reluctant to do so with it only tacked together... A logical point would be following the SB and D pieces are installed but before the rear suspension mounting tubes?

Matt

Sounds about right to me, if you have fully welded the bottom rails and have at least one full weld on all the tubes you'll be able to move the chassis. How ever you might need to clamp the chassis back down flat on the build table and tweek the uprights back into place. You could make 3D cardboard mock ups of your engine and box might be alittle easier to lift in and out of the chassis?

Hi Matt

Quite a difficult one is this.

Normally I would say that once you assembled all of the chassis as far as & including the seatback area, it would be safe to fully weld the chassis.
The rear frame & diff cage etc could be welded in later :)

I guess you'r main problem is the fact that you cannot assemble the transmission tunnel as yet.
Personally I would be worried that the chassis may distort if that area was not completed before fully welding ;)

If you only need to move the chassis from the build table for a short period of time, provided it has been tacked well, it should not go out of shape.

Once you know the layout of the tranmission tunnel the chassis could be returned to the build board for final completion :)

Hi Matt,

sounds like you are really cracking on with your chassis build :cool:

You,ve had some very sound advice from Talonmotorsport & Ronnie :)

As suggested earlier in the week, bear in mind the "Footwell space" when deciding on the postion of your transmission tunnel, as you are fitting the MX5 drivetrain you may well be able to use the "Type 9" dimensions for the tranny tunnel & not lose any footwell space,

look forward to hearing/seeing the final position you decide upon for the tunnel.

cheers
andy

Thanks Guys.

I took some very rough dimensions off the engine and gearbox last night. It (the engine) is very short - less than 500mm long but also 500mm wide with a 100mm offset towards the drivers side meaning that most of the weight of the engine will be biased towards the drivers side of the car - great for corner weights....not.

The width means that it is going to need to sit further back in the chassis than I'd hoped and also the bracing top rail within the engine bay will need to swap sides.

The bell housing is 350mm at the point it will enter the tunnel again with a bias towards the drivers side falling to about 175mm at the box.

BTW are the book dimensions for the Type 9 or the other one?

Matt

Book dims are for type 9. There is a sticky somewhere with the dims for the mt75.