Yesterday was some cleaning up around the yard, making a new vegi patch, doing retic, planting seeds, then fertilizing all the fruit trees, all the gardens and the lawns. By that time the day was nearly over, but managed to squeeze in a couple of hours on the car.
Got the lower a-arm mounts made, and gone one of the tacked onto the frame in the required location on the chassis.
There are three mounting locations available for me to test out when its all running again. The lower most hole is at the same location as the modified mount that I had on the original sub-frame. This now gives me the option to go higher than that point to test out how the car feels with these different roll centers.
Got a good chunk of car time today were I continued with the suspension mounts. This time it was on the caster arm mounts.
Once I’ve added the last chassis bars to this mount, I’ll profile it to remove the excess material (like the lower a-arm mounts have been)
I then started preparing the mounts for the steering rack. I’ve cut out the profiles that are needed to mount the rack, so they will fit tightly over it locking it into position. Didn’t get a pic of these, so you’ll have to use your imagination 🙂 These will bolt onto the main sub-frame that will run across the engine bay. These bolt locations will be adjustable up and down, as well as for and aft via some shims. This will allow me to make changes to help take out any bump steer and also to change the amount of Akerman angle that the steering has during a turn.
Next on the list was to build the sub-frame to hold the steering rack mounts into place. I didn’t have the metal I needed, so I spent some time trying to work out what the framework in the front end will look like. I used some high tech masking tape to mock it up :). I’ve tried to set the bar work up so that it will be easy to change to work at its best once I have changed the front suspension over to double A-arms – rather than the MacPherson strut setup that it has now (A-arms are a much better race suspension, but the mount at a different location).
Pic on the left is taken from above, the second one taken from underneath.
The framework is going to be quite extensive, so to determine how I was going to get things like radiators and intercoolers to fit I put them in.
The whole assembly will be moved back a little bit from the photos here, as I have now removed the coolant swirl pot and I’m going to mount it on the side of the motor. This gives me another 100mm to move the radiator and intercooler back. Also on the list is to cut off the outlets of the intercooler and radiator and rotate them around to point them in the right direction to suite their new homes.
I made a few adjustments to the proposed frame after this fitting, to make better use of the tubes and to reduce the size of the mounts that will be needed to hold the rad and cooler in place.
I’ve taken the measurements of all these tubes, now I just need to work out the tube sizes required so that I can buy a couple of them tomorrow. I need to analyse the forces on the tubes in order to select the right tube size to make it strong, but also very light. A tube that is put into compression needs to have a larger diameter to take the forces. A tube that is purely in tension can be a much smaller diameter (ie lighter), but may need a higher wall thickness.
Until next time…