Actually, I converted the steering from a rear steer to a front steer, then used a 11 1/2" aftermarket rack n pinion. I moved the front axle C/L forward 1.75", and had to run the tie rods and rack way up high to minimize the bump steer. The results are 18 1/2" of usable travel with about 1/4" bump steer. At full bump, the frame is a scary low 2" from the ground! Notice that I used the stock cast spindles, but reversed them (I used the driver side spindle on the passenger side, and vice versa) and utilized the stock steering arm as a platform to mount the elevated tie rod ends to. Although the spindles are cast iron, I was still able to effectively weld them with the proper pre and post heating. I used 3/32" Nyrod (arc welding electrodes) and cleaned of 100% of the flux on the outside of the rods before TIG welding the spindles. It is a laborious effort, and takes almost 7 hours just to weld one spindle and that's after it has already been tacked together! (this is due to the fact that it takes numerous trips to the oven while welding as not to allow the temperature of the spindle drop below 375 degrees) I have decided to fab 100% of the new spindles for our 4 seat chassis out of 4140 alloy steel. The extra tenth of a percent of carbon in this alloy allows it to accept a heat treat. These UTE's pull left to right bad enough as it is. I could only imagine the additional handling challenges if you added excessive bump steer to the equation.
So, I was speaking with this fabricator at the mint. He modified one of the Mavericks (Lansky's, I think) similar to ours in regards to the front steer conversion. I thought it was cool that the position of their steering arms was similar to ours. Whether or not he got it from my posts is not as important as it being in the right position. Unfortunately, the car lost both rear cv's, but they got them replaced in only 12 minutes, so they posted! Incredible job guys!
Anyway, the fab guy said that all the prep and welding jargon that I went through to weld my modified spindles was unnecessary. He claims that he just ground smooth the surface of the spindle, then TIG welded it, using conventional means, meaning no pre or post heating, and I think he said that he used a mild steel rod (most likely E-70s2). When I asked him what about the carbon content, and porosity in the casting, he claimed that it was a different type of casting. Similar to a nodular casting (used in quality, high stressed components, like 3rd members and truck spindles). When I ran a test weld before fabbing our spindles, I welded a small piece of 4130 to the spindle, as delivered from BRP, and with no preparation other than grinding off the paint. It broke right off with a pair of pliers, so I treated it as a sand casting, and applied pre and post welding processes that was necessary to achieve a sound TIG weld in cast iron (that caused the welding to be in the area of 8 hours per spindle). I'll add more later. Gotta go.
So, to finish my thought, there is no
proper way to TIG weld onto cast iron. Not to my knowledgeat least. Now, I'm not even sure that the spindles are a sand casting, based on what I've learned over the weekend. They sure exhibit the characteristics of cast, and I will still treat them accordingly. Arc welding is the best way to achieve reliable results. Due to the intricate and numerous pieces (over 12 separate plates per spindle) required to assemble our spindles, bulky arc welding was not an option. Although I was certified in MIG and TIG welding in the past, an arc welder I am not!
I am not condoning the simplified welding process suggested to me at the Mint race. I will say, that the spindles on the Maverick that he modified were still holding together after the first lap, whereas if I TIG welded them as per my first test piece that I ran prior to fabricating our spindles (without all the pre and post treatments), they would have failed in the first couple of miles. I will now make a point to ask the engineers at BRP about the composition and manufacturing processes used on the stock spindles. I hate being wrong
but, I love to learn!