Click here for Part 1.
All text and images taken with permission from http://www.nulonnationals.com.au/2016/03/18/xr6-turbo-ute-part-2/ with some edits
It`s been a very busy week in the shop, with the Ute now rolling. Ian and Grubbo’s focus shifted onto the very intricate roll cage. As this Ute is getting built to run in a range of different forms of Motorsport, the cage not only has to protect the driver in the event of a roll over or high speed touch up, it also has to give structural rigidity.
With this in mind, the decision was made to link all 4 suspension pickups through to the cabin itself. The masters of fabrication came up with a crazy design that not only goes through the firewall, but also comes through the back to link the 300zx rear end. The main ingredients for part 2 is roll cage tube and man hours.
Once the boys gave the cab a bit of a clean out, it was time to start measuring the main hoop. This is very important to the entire roll cage design, get this one wrong and the rest of the bars will also be out of alignment.
The key to a great roll cage is to keep it to the same shape as the roof line. Having done many hoops in his time, Grubbo got this one spot on, it isn’t going to get in the way too much. This is the perfect platform to start the cage.
Next up it was time to bend the front stays to shape, These are the most important bar when it comes to forward vision, so many times we have seen cages at the track that do the job of protecting the drivers but limit vision off to the sides of the car. In time attack racing this doesn’t matter too much, but when you are in door-to-door racing, drifting or even hillclimbs, the more open space in the cab the more confident you feel as a driver.
The rear stays are connected to the outside point of the suspension pickup. Although it looks a bit funny now remember that there is a tub to go on that will hide most of this bar work.
Front and rear stays are in, its now time to focus on the dash bar as well as the first unique features on the side intrusion bars.
Ian Porter is over 6 ft when he is on his knees, so we had to make sure that the side intrusion bars gave him enough room to get in and out of the car while maintaining a high level of side impact protection. Grub came up with this interesting design that not only gives Ian the space he needs, but looks incredible as well. As you can see, we also ran a bar down the centre of the cab which ties the dash bar to the harness bar in the back.
Time to go forward of the cab, These bars are joining the dash bar to the front suspension points, in this case the strut tower is very solid and doesn’t need reinforcing.
Things are getting serious when you cut holes to add metal, not take it away. Speak to anyone that has driven a cage than protrudes from the cab to the strut tower, they will tell you how much stiffer this makes the entire car. Do it once (or twice) and do it right.
The factory holes in the firewall didn’t quite line up with where the bar was going to sit, so we had to cut a new hole and will fill this in once the fab work is finished and the running gear is stripped for paint.
Once the front end was finished, it was time to focus on locking this rear end into the roll cage. This is more basic with 5 straight bars, linked together to make a super strong rear section. This section of tubing is going to end up taking all the weight of the fuel cell, rear body work as well as the huge downforce from our custom time attack spec wing. (more info to come)
Without giving too much away, here is the rear section finished off with the fuel cell mounting bars as well as the body test fitted. it is now starting to look like a ute again. Over the weekend the boys will focus on making a new front reo to pull some weight out of it as well as the plenum and intercooler mounting.
Stay tuned for more updates on this ute, as the boys are moving very fast on it. They are aiming to have it ready for May 14th to take on the great Mt Panorama.