Hi from Australia

[Peter Tommasini]

Welcome to the site Ismar

[Ismar1984]

Yes, the rails are McDonalds brothers and they made the 4 link arms for me as well, though i am using my own brackets as the arms are not equal length and the 30.5' tyres posed some problems in regards to arm positioning on the diff housing.
I will be welding the X-member in but it will have through holes for the exhaust and the centre section will notched to accommodate the transmission. Do you think its a bit of overkill? I really don't want to have any issues when it comes to torsional testing for engineering and the engineer seemed pretty happy with the design when i showed him the CAD model.

It'd be great if you could have a closer look one day. i'd love to get some input from someone with experience in chassis fabrication.

[Toprodz]

The issue I think that you are going to have is that the X rails look to be 75mm x 50mm (2X3 for our american cousins) is that you are going to end up with a pretty high tunnel through the car going by the picture showing how low the car is sitting with the wheel, in the wheel arch, as the height of the pinion on the diff looks like it will be higher than the floor at the rear, also with the car sitting that low you won't be able to run the exhust under the car, so it is going to have to go through the rails, so if are running a 2 1/2" (63.5mm) exhust pipe there is not much room left in the x pieces to put holes through them for the pipes, and have clearance around them, if there was it would make them very weak.
I am happy to come look and discuss the options to make it work

[Ismar1984]

thanks for the input Peter, you're right the tunnel will have to sit pretty high but i am not too fussed with that as i only plan on having two seats in the back.
For the rails i am using 100x50mm RHS so that should help a little with the exhaust going through, I also plan on doing an oval exhaust so as to minimise the amount of material taken out in one direction.

I'll give you a call later in the week, I am in Rosanna so not very far from you.

Thanks,

Ismar