In an outrageous attempt to install my downpipe backwards, TDC Auto (now Heads Up Motorsports) extended one side and shortened the other. They also moved the o2 bung from the top to underneath the bend relative to it's newly installed orientation. Why they used a square patch on a round tube is beyond me, not to mention the fact they had to grind down the welds. As shown in the return pictures from TDC, this backwards downpipe was not going to work at all due to proximity to the throttle cable. But now when installed correctly, among other obvious length issues, the newly positioned o2 bung sits solidly on one of the header tubes. I took my car there initially solely for the TIG welding, but they wouldn't work on it unless they did the fabrication as well. It obviously required more skills than they were up for.
This is how it's done.
Over the last year I've had Tony of WETSU come out and weld a few things I've needed TIG'd including sectioning strut casings, attaching camber plates, and using my chicken scratch to assemble newly machined engine and transmission mounts. Now it was the downpipe, and soon after, the full exhaust. Tony is a great guy to hangout with, not to mention a great welder with years of experience. I would get as much fabrication done before each of our visits so that it was a relatively quick and painless process. Good preparation, no matter how long it takes, reduces the final cost directly by less welding time. Indirectly and more importantly, the better it's setup, the less likely you'll have to recycle the process entirely if, god forbid, it doesn't fit when it's all said and done!
Tony also just happens to have not one, but two of the cleanest 2+2's I've ever seen. A his and her's pair, they've got less than 5o,ooo original miles on them COMBINED!
I spent the better part of an evening cutting the now forward vband flange off the downpipe. I ordered a foot section of 3" stainless tubing from verocious motorsports online, with great customer service and fast shipping I might add. I also got (2) 3/8" 90* stainless exhaust hangers, a 3"x4" stainless turbo flex joint, a stainless EGT bung for a greddy sensor, and finally a new vband with stainless flanges. For some reason the vband flange that was on one end of the downpipe did not really fit any of the other vband flanges, on the turbo adapter nor exhaust. That I can't really explain, TDC? Anyone? Instead of trying to make it work I cut it out to put in a matched pair from vibrant.
I cut the tube long and started trimming back to adjust the length and angle to position the downpipe where it needed to be, namely not taking up the same time and space as the throttle cable, or any number of other things within inches. After returning the vband flange from the rear to the front (the one that was originally on the turbo side of the downpipe), I taped the vband flange to the perpendicular side of newly cut extension tube. Once everything was cut correctly, I did the same to the extension/downpipe connection. I didn't have access to a tack welder so tape did the job to securely orient the tubing during transport. After arriving we mocked it up in a vice, marked the vband/extension with a sharpie and started welding the aft joint.
After welding one side of the extension, we put the vband back on and attached it more permanently.
On my way to Tony's, I picked up some carefully sized hole cutting saw drill bits and made sure to pack my drill. I cut out the o2 bung with a hole saw that's id was just bigger than the od of the bung itself. I cut another hole in a scrap piece of the same 3" tubing I used for the extension, the id of the saw of which matched the od of the previous hole. We welded this patch, which was curved at the exact dimension as the downpipe of the exact size, to patch the hole made from the bung being cut out.
The drill didn't make it, the clutch wasn't strong enough for this many holes or size. Tony had a few spares, and a small corded one worked well enough to finish the job. Ultimately I was able to return the drill for an exact match, if not a slightly upgraded one. Thanks Walmart.
I then took a third hole saw with the same od as the original hole saw's id, which also just happened to match the current od of the bung, and cut a hole in the downpipe where it needed to be. We then welded in the bung. I placed the bung angled outward on the lower downpipe section, away from the firewall and headers, where based my very accurate description and visual aids, TDC tried to put it in the first place, with limited success.
This is how it's done.
Over the last year I've had Tony of WETSU come out and weld a few things I've needed TIG'd including sectioning strut casings, attaching camber plates, and using my chicken scratch to assemble newly machined engine and transmission mounts. Now it was the downpipe, and soon after, the full exhaust. Tony is a great guy to hangout with, not to mention a great welder with years of experience. I would get as much fabrication done before each of our visits so that it was a relatively quick and painless process. Good preparation, no matter how long it takes, reduces the final cost directly by less welding time. Indirectly and more importantly, the better it's setup, the less likely you'll have to recycle the process entirely if, god forbid, it doesn't fit when it's all said and done!
Tony also just happens to have not one, but two of the cleanest 2+2's I've ever seen. A his and her's pair, they've got less than 5o,ooo original miles on them COMBINED!
I spent the better part of an evening cutting the now forward vband flange off the downpipe. I ordered a foot section of 3" stainless tubing from verocious motorsports online, with great customer service and fast shipping I might add. I also got (2) 3/8" 90* stainless exhaust hangers, a 3"x4" stainless turbo flex joint, a stainless EGT bung for a greddy sensor, and finally a new vband with stainless flanges. For some reason the vband flange that was on one end of the downpipe did not really fit any of the other vband flanges, on the turbo adapter nor exhaust. That I can't really explain, TDC? Anyone? Instead of trying to make it work I cut it out to put in a matched pair from vibrant.
I cut the tube long and started trimming back to adjust the length and angle to position the downpipe where it needed to be, namely not taking up the same time and space as the throttle cable, or any number of other things within inches. After returning the vband flange from the rear to the front (the one that was originally on the turbo side of the downpipe), I taped the vband flange to the perpendicular side of newly cut extension tube. Once everything was cut correctly, I did the same to the extension/downpipe connection. I didn't have access to a tack welder so tape did the job to securely orient the tubing during transport. After arriving we mocked it up in a vice, marked the vband/extension with a sharpie and started welding the aft joint.
After welding one side of the extension, we put the vband back on and attached it more permanently.
On my way to Tony's, I picked up some carefully sized hole cutting saw drill bits and made sure to pack my drill. I cut out the o2 bung with a hole saw that's id was just bigger than the od of the bung itself. I cut another hole in a scrap piece of the same 3" tubing I used for the extension, the id of the saw of which matched the od of the previous hole. We welded this patch, which was curved at the exact dimension as the downpipe of the exact size, to patch the hole made from the bung being cut out.
The drill didn't make it, the clutch wasn't strong enough for this many holes or size. Tony had a few spares, and a small corded one worked well enough to finish the job. Ultimately I was able to return the drill for an exact match, if not a slightly upgraded one. Thanks Walmart.
I then took a third hole saw with the same od as the original hole saw's id, which also just happened to match the current od of the bung, and cut a hole in the downpipe where it needed to be. We then welded in the bung. I placed the bung angled outward on the lower downpipe section, away from the firewall and headers, where based my very accurate description and visual aids, TDC tried to put it in the first place, with limited success.
Finally, we welded the stainless EGT bung into the extension just aft of the forward vband, on the underside of the downpipe. I obviously need a better picture organizational system, but I'll find pictures of that and the downpipe's final position in the car soon. Don't expect anything less than perfection.
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