The Road to Speed Week 2014 Part 4: Return of the Sheet Metal Whisperer
I’m greeted by the sounds of classical music as I walk into the garage of Specialty Cars Fabrication which is nestled in a corner next to the Fullerton airport. A bright light strikes out from the torch of a tig welder and illuminates the front of a welding mask. The man underneath the mask is John Kuchta, owner and proprietor of Specialty Cars Fabrication. Calling John just a fabricator though, would be an understatement and a borderline insult in my opinion. Put simply, he’s in artist and metal is his canvas.
The last time we covered John’s talents in depth, he was massaging metal into the one of a kind dash that now resides in Project 240SX LSR. This time, we’ve come to him to complete the last bit of plumbing required as a result of our Turbosmart waste gate relocation as well as our swap to a VQ35DE fly by wire throttle body. At the same time, we also wanted to rid Project 240SXLSR of its full exhaust system in favor of a fire breathing, side exit race exhaust. There is little else that can give us gear heads such instantaneous wood.
To construct the boner inducing exhaust, John Kuchta starts with a series of stainless steel bends from Burn’s Stainless. Over the past few years, we’ve talked a lot about combating the corrosion issues that we’ve encountered from racing on the salt. Our best ally in this fight has been to use stainless steel on anything we can, from fasteners to the bodies of our KW Suspension coil overs. The exhaust system is no exception.
The down pipe starts at the turbine housing outlet in the form of a round 3” mandrel bent tube. After it makes a quick, but smooth bend towards the ground a 3” round to oval transition is joined to the assembly via a single slip connector. This is where things get tricky.
Due to time limitations, space constraints underneath the car, and the unavailability of an oval bend along the oval’s minor axis, John Kuchta resorted to creating a complex oval bend utilizing pie cuts. In this technique, straight pieces of pipe are cut at angles and then welded together to make a bend. In our case, 9 pieces of pipe were cut at 10 degrees each to produce the very tight 90 degree bend in our exhaust.
In Japanese they call pie cuts “wagiri yousetsu,” which when translated into English roughly means “circle cut weld.” Though John Kuchta claims it really means, “no profit.” After seeing how labor intensive the whole process is, I’m inclined to agree with him.
The rest of the pipe was created using a combination of straight lengths of oval pipes and the wagiri yousetsu method, this tie along the oval’s major axis. Burn’s Stainless actually manufactures the oval pipes with a bend along the major axis. However, it turns out that Burn’s stainless isn’t open at 4 AM on a Saturday night. Funny, since the middle of the night seems to be when most racecars get built.
Using 3” oval piping versus a traditional 3” round pipe, frees up just shy of 1” of additional ground clearance for us.
With the main exhaust pipe tacked up, John’s attention turned towards fabbing up a new set of waste gate dump tubes. At the same time, he took the opportunity to play with a new toy, the Icengineworks block modeling system.
The Icengineworks header modeling kit eliminates time consuming trial and error that results from fabricating headers and manifolds on the fly. By linking together a series of small pieces which are the same diameter as the piping, the fabricator can plan out complex bends and create a physical prototype before cutting any steel.
With the steering rack, turbo system, and the frame rail all residing in the same area, there simply wasn’t much real estate left for the waste gate dump tubes. Using the Icengineworks modeling kit, John was able to precisely mock up each tube.
Two Burn’s Stainless double slip connectors are used to join the second portion of each waste gate tube. A slip connector is used to add flexibility into the system. The double slip design from Burn’s Stainless improves sealing of the exhaust gases in comparison to a single slip connector.
The springs that hold the double slip connector in place can be a slight pain to install. By using a special tool he made and holding his mouth just right, John Kuchta installs the each spring while MotoIQ contributing editor Annie Sam looks on in admiration.
With the springs installed and the waste gate pipes in position, you can see how much competition for space there is in the engine bay of project 240SX LSR.
With his plumbing skill and iconic mustache, I’m starting to think that John Kuchta might be related to the Super Mario Brothers. Agree?
The end result of John’s hard work are two waste gate dump tubes that fit snugly into place and just squeak by the steering column and frame rail. On another note check out our new Turbosmart wastegate position sensors. We’ll be data logging the information from these with our AEM AQ-1.
Here you can see how the collection of exhaust pipes snake by the frame rail. It’s definitely a tight squeeze.
With the exhaust finished up, John turned his attention towards fabricating a new intercooler pipe for Project 240SX LSR.
One new intercooler pipe was required since we swapped to a fly by wire throttle body system from a VQ35DE which is longer than our original N1 throttle body. Previously, our intercooler was positioned so that a simple 90 degree bend could be cut from a U bend to produce the needed intercooler pipe. It was simple and required no welding at all.
The longer VQ35DE throttle body didn’t leave much room though and required a really tight bend so John again resorted to the wagiri yousetsu method.
Once all of the intricate pieces were tacked together, John Kuchta then finish welded the intercooler pipe.
With all the fabrication complete, we’ll return Project 240SX LSR to 5523 Motorsports so that the last of the wiring can be completed. Then, we’ll finally be off to dyno tune our new AEM engine management at Jim Wolf Technology. Stay tuned.
