Evolution is the way of the world, in all aspects, and your car projects will evolve as you tinker with them or build new projects. Turbocharging or supercharging an engine is fairly simple and can be done inexpensively, but there are a few places where skimping can cause headaches. Leaking boost flex hoses and clamps are the bane of existence with many DIY turbo setups. A good way to correct this issue, is by replacing the silicone or rubber hose connections with V-Band clamps.
These style clamps are a little more complicated, but give 100% seal once installed correctly (even under high boost applications). They’re made up of two outer rings that are welded to each side of the tubing that you’re connecting. On the Vibrant brand flanges, used here, one flange will have an O-ring groove and the other is machined flat for a perfect seal. The pieces are then clamped together with a round clamp, that has a groove in it to hold the shoulders of the sleeves together, so they can’t come apart. These clamps are the choice on racing engines and of many custom car builders, so naturally they’ve taken off in the DIY custom car world. We decided to document the installation of a few of these clamps and show you the process.
The biggest thing with installing these clamps is that you need to clean them and the parts you’re welding them on REALLY well. Aluminum is very easy to weld, when you get your joints prepped correctly and you’re diligent with cleaning the parts. For this project, I was welding the large clamps to the inlet and outlet of an intercooler and a 90 degree cast elbow to the charge pipe off the turbo, which is also cast aluminum. My life was made a little easier, because the manufacturer of the intercooler had welded machined tubing to the cast end tanks. This meant that I was welding the larger clamp sleeves to nice fresh aluminum tubing and not cast aluminum. Cast aluminum can be tricky, because of the way it holds in dirt and oil. It can be “dirty” by nature, in how it was cast, so I am always happy to get around that!
These large parts all had a barbed flanged end on them for holding silicone or rubber hoses with a traditional hose clamp. I decided to bevel the barbs so that they slip fit into the recessed shoulder that is machined inside the v-band flanges. For this process I used our pneumatic right angle die grinder with a 36 grit Roloc disc and worked my way evenly around the flange. Once I had a tight and even fit around the v-band flange, I removed everything and began prepping the parts to weld.
The areas I had hit with the rolloc were pretty clean, but the ridges in the clamp flange and the barbed ends, on the parts, are notorious for trapping dirt and corrosion. Even though the parts are all new, they can still have dirt and impurities trapped that could pop out once you start putting some heat into them. I took a stainless wire brush and cleaned around all of the edges, making sure I had an even dull silver finish. It doesn’t hurt to clean an area an inch or two wider than where you’re welding, just in case the heat makes anything pop out of those areas. I then took our Aluminum prep and wiped off every weld surface, and the areas surrounding them. You’d be surprised at how much comes off, just from dirty hands and grinding dust left on the surface!
With the areas all prepped, I turned my TIG 200 on and adjusted my settings. The first parts weren’t cast, so I was able to set the clearance effect fairly negative, at -4, for a small puddle footprint. I also love running a gas lens on my torch, ESPECIALLY when welding aluminum. The superior gas coverage, of a gas lens over a traditional gas cup, allows for a more negative clearance effect setting. I had a helper firmly hold the first flange in place, while I made two tack welds 180 degrees from each other.
Above you can see the fit-up of the part and the first tack weld. From here, I chose a direction to work off of, and I started welding around the tubing. A tip for when you start welding again, is to start your weld halfway back, into your last weld. This allows you to lay a dab of filler rod, which will overlap the last weld. This ensures that you don’t have any pinholes or gaps where you started and stopped.
When welding tubing, the biggest challenge that I, and many other DIY guys, have, is keeping the torch angle correct and moving consistently around the tubing. If you see your torch burning the filler rod before you dip it in the puddle, you have your torch angle too steep. To correct this, you need to adjust the angle, sometimes it’s just a slight wrist movement! Unless you have a turntable, or you’re a contortionist, you’ll be forced to stop every 1/8th or 1/4 of the way around the tubing to readjust your hand, or the part, so you can finish going around. If I had to pick, I’d rather start and stop more, and have quality welds, over potentially welding, at an incorrect angle, and having the weld puddle get too large and burning through!
Make sure you go back and check your welds for any potential pinholes, or spots. The nice thing with TIG welding is that you can reheat an area and add another dab of filler, or melt a puddle flat.
On the cast parts, I had to change my clearance effect setting, a little higher, towards the positive realm (around -2.75 to -3). This was because I was getting a brown halo around my welds, on the old setting for the clean machined parts. This part is tricky, especially, if you’re welding on an older, used cast part. It may take a sacrifice, in weld puddle size, to keep the weld clean. I like to pre-bake used cast parts, before welding, to bake impurities out ahead of time. Because the cast parts were thicker, and took more cleaning, I favored the cast portion of the weld joint when starting my weld puddle. This allowed the TIG to get a jumpstart on cleaning the dirtier cast part, and once I had a small puddle started, I moved the puddle over to the machined v-band collar and got a puddle going there, so I could add a dab of filler rod. Once you get the puddle going, and a nice cleaning “halo”, it’s business as usual. I had a couple spots where I had some impurities pop up, and I got a small brown halo, but nothing major. If you’re seeing “pepper” specs, in your puddle, as you’re welding or the weld puddle has porosity, you need to stop and clean the part more….No exceptions! This could take sanding more, wiping with Aluminum Prep, or baking the part at a higher temperature. Clearance Effect, on the machine, helps clean the metal before starting a puddle, but it is only for removing light surface corrosion! I was actually a bit surprised at how dirty some of the welds were on the intercooler welds….must have been made at 4:30PM on a Friday!
With the parts all welded, I assembled the parts with the v-band clamps and made sure everything fit together correctly. All seems well, and now these parts will be sent to be pressure tested for any leaks. If any small leaks pop up, we can go back and reflow the weld and correct. Eventually, these parts will make their way onto a friends RB20 powered Nissan 240ZX drag car. It should move down the track pretty well and surprise more than a few american muscle cars!!