exhaust work one

I placed an order with verocious motorsports online which included a (1) 4" long x 3" dia stainless steel (including ends) turbo flex joint, (3) 90* 3/8" stainless steel hangers, (2) rubber exhaust isolators, (1) 1' long x 3" dia stainless steel tube, (1) stainless steel EGT bung, and (1) 3" vibrant stainless steel v-band clamp with flanges. Great service.

I used the foot piece of tube to extend either ends of the downpipe, attaching v-band flanges forward/aft. The EGT bung went near the front flange of the downpipe in the lower part of the small extension. I also had v-band flanges on both ends previously, but for some reason the second flange set didn't match up now, almost like they weren't mated machined flanges. This may have had something to do with the trip to TDC Auto, but either way, when I flipped the downpipe into the correct orientation, I used the old v-bland flange that actually did match the turbo adapter, and tossed the other miss-matched pair.

I mocked the downpipe, cutting the aft extension to the right length and angle before tig welding and wrappings. Note the perfect o2 bung location. Since I didn't know where the exact position of the aft flange or the rest of the downpipe needed to be, not to mention relative to the exhaust, I needed to mount the downpipe first as a starting point. After positioning the downpipe by itself, I had the bungs and front flange and extension welded in one visit, and the aft flange and extension, not to mention the entire exhaust after it's mock up, welded in the second visit.

WETSU Welding to the rescue. Thanks Tony.

Because of the distance of the entire exhaust (ie a little error in angle or location six feet out would make a huge difference in the final location of the muffler tip),  I decided I could not mock the exhaust like I did the first part of the downpipe, with tape. I borrowed a light duty mig welder from a friend at work and tacked the mid/aft hangers, flex joint, flanges, and aft downpipe extension into place before driving it to Tony's.

Yes, that's a full, single piece exhaust on proper stands, being back purged with 1oo % argon during tig welding said hangers, flex coupler, and v-band flange.

And yes, the pair of z's are still chillin in the garage.

The flex joint is sized to slip over the pipe, which aids in mock up and welding. I was able to angle either side of the exhaust tube and play with the installed overlap to get the final angle and position of the flange face perfect during mock up without pre-stressing the flex joint at all. Based on the amount of work TDC Auto did to the forward section, I was impressed that I didn't even have to cut and re-angle the exhaust tube and create another joint to align everything. When I first mocked up the exhaust, the front flange was about a foot from where it needed to be, but now with the flex section installed and the hangers in the correct positions, it was perfect.

Tony covered the entire radial thickness of the stainless end caps of the flex section with weld. This capped off the ends, permanently anchoring the stainless braids.

When welding the flange I followed the od weld from the id with the back purging hose since we could no longer plug the end of the exhaust to create the atmosphere while welding in the same area.

To get great welds, the surfaces must be just as clean. We touched up the joints and flange faces prior to welding to remove the excess left over from the tack welder.

I've got a few videos of the below v-band flange welding process while back purging that I'll post later. The welds look just as good on the inside as they do on the outside.

From here we mocked up the downpipe for the last time, securing it to the table with a solidly mounted chain fixture, plugging the ends, and back purging it as with the exhaust. It helps significantly having the right tools for the job. One great example you can see is the braided ground that is looped around the stainless tube of the downpipe, as well on the midsection of the exhaust above.

Back at the barn.

The exhaust hangers could have actually thrown off the entire fitment pretty easily. The forward flange face angles and location, mid section height relative to the bottom of the car, and exhaust tip to rear valence are easily changed based on minor movements of the exhaust hangers.

During mock up I lined the mid hanger to the rubber hanger and tacked it into place. Because of the hanger arrow end, I could not slip it into the rubber hanger as it would sit when installed, so the exhaust sat just rearward. Hopefully when it was pulled forward to be installed it would still sit as planned. I could not even access the rear hanger as it was entirely behind the rear valence, so I marked the center top of the muffler, relating the installed position to where the rubber hanger was, and tacked the hanger accordingly. It would have been very easy to get the mid hanger at the wrong angle/height/location, let along the rear.

As it turned out, both hangers broke off, one completely, during the ride over to Tony's. The tack welds weren't enough to hold them, but were enough to re-attach them in the same location by aligning the remnants left on either side. I was still pretty worried nonetheless.

The welds look amazing, as usual. For those of you who were wondering, the mid hanger on the exhaust attaches to an opposing hanger and isolator on the transmission cradle. Nothing was tacked to the bottom of the car or floorpans. I may or may not have installed pictures of this specifically, it was getting late in the day and only took two seconds to weld the last hanger to the transmission mount and I didn't get any shots of it during fabrication or mock up.

As a final note, do not expect to easily install the rubber isolators over the hangers, tack them in place, and remove them. I did this during the first mock up and I had to remove the entire transmission mount from the car, spending the next 3o mins trying to remove the isolator from the hangers. In the end, I had to break the tack weld, feed the hanger all the way through the isolator to remove it from the non-arrow side, and start the mock up completely over.

Only in South Carolina ...

wetsu welding

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.

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.