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Swapped the factory X-pipe on my 2019 GS the other day for the AWE X-pipe. I did the swap to cut down on tunnel heat from the secondary cats. During 20-30 minute track sessions, the tunnel gets a little toasty. I did the same with my 2013 GS using a Corsa x-pipe and it was beneficial regarding heat. Thought I'd share some observations about the AWE pipe....
The Good...
- Very straight-forward swap. Fortunately I have access to a lift so it was a 30 minute or so job, with the longest part being the R&R of the tunnel plate and its 24 bolts. As an aside, a little squirt of penetrating oil on the joints makes separating the factory pipe from the over-axle pipes easier
- Dimensionally the AWE pipe is a perfect match for the OEM pipe. No trying to find a "sweet spot" to get it to line up or ensure there's enough bite where the pipe slides over the over-axle muffler pipes.
- The pipe is well made, no dents/crush points at the bends like the OEM pipe
- Saves ~5 lbs vs the stock pipe
- The rear of the pipe is slotted where it installs to the over-axle pipe, in theory allowing it to seal
- It slid right over the over-axle pipes. A little WD-40 helps them to slide in place
Not bad...but disappointing
- The AWE hardware to connect the pipe to the main cats consists of some really cheap bolts, washers, and lock washers. AWE doesn't provide any torque specs. A quick search showed that Corsa and Borla listed ~30 lb/ft for their hardware. OEM is 18 lb/ft. I torqued the AWE hardware to 22 lb/ft and the bolts started to deform. Seriously? <smh> Fortunately an Ace hardware store was across the street so I bought some Grade 8 black-oxide flange bolts and nuts. The flange nuts are locking nuts like OEM so no need for any lock washers. I added some anti-seize so the threads don't rust....at least not too bad....and the bolts can be removed at some point in the future (likely next oil change) for replacement with stainless steel hardware or zinc coated hardware. I torqued them to 20 lb/ft. Yes Grade 8 is waaaaaaaaaaaaaaaay beyond overkill. But it's all the store had
- The Accuseal clamps in the rear seem like knock-offs. At 65 lb/ft I still have Very slight exhaust leaks at each joint. I have band clamps on the way to replace the AWE clamps.
- Bottom line is that AWE could add $30 worth of nice hardware and the whole assembly would be OEM equivalent. Also, adding a couple torque specs to their instruction sheet would be nice. The front bolts at 18 lb/ft were fine but why make people guess? Don't they know how many car guys are OCD with specs?
Sound
- I know many buy the pipe for sound. As has been written by many others, it's very slightly louder at idle in Tour, Sport, or Track mode than stock. During cruise, also slightly louder. No drone. No WOT observations....that will be at my next track day.
Pics show the cheap hardware. Didn't bother to take any pics of the new stuff.
Sound Clip (I switch to Track mode around the 40 second mark)....
wow great write up, i am surprised that the hardware is so crappy....i was thinking about having my shop put one of these on. Given that I dont want to spend multiple $$$$'s on a new exhaust but want it louder, this seems like the most logical step. Looking forward to hearing how it sounds on the track!
I didn’t install an AWE but mine came with the same rear clamps as yours and I believe they’re the same as the factory ones. I did find that my factory set up had soot at the clamp areas which tells me it was leaking slightly also. I to thought about replacing them with a wider stainless band clamp but I’m not sure if there’s enough room on the tail pipe before it turns up over the axel to get a good seal.
I didn’t install an AWE but mine came with the same rear clamps as yours and I believe they’re the same as the factory ones. I did find that my factory set up had soot at the clamp areas which tells me it was leaking slightly also. I to thought about replacing them with a wider stainless band clamp but I’m not sure if there’s enough room on the tail pipe before it turns up over the axel to get a good seal.
They're very similar to OEM.....but not quite. Mine too had a little soot around the edges but I couldn't feel anything while moving my hands around the OEM pipe joints. I did that for a "comparative" data point. With the AWE supplied clamps I can easily feel the exhaust blowing against my hand. In the two pics below, you can see how the OEM clamp nicely deforms in order to seal while the AWE clamp wouldn't....even after multiple attempts....
OEM Clamp AWE Clamp
Is what it is. I like the band clamps since they grip both pipes. I'll install them this weekend. The car is already in the air, so it'll only take me 10 minutes to do it
You don't have that clamp fully tight. If you torqued that to a specific spec, you can't...at least not at the point you are at in tightening it. You have to tighten it until the top band collapses. On these aftermarket clamps it is most easily accomplished with an impact and takes a lot of torque.
Last edited by subieworx; Jan 2, 2020 at 09:16 AM.
You don't have that clamp fully tight. If you torqued that to a specific spec, you can't...at least not at the point you are at in tightening it. You have to tighten it until the top band collapses. On these aftermarket clamps it is most easily accomplished with an impact and takes a lot of torque.
At 80 lb/ft.....60 is what they say to tighten it to....I stopped. I have an impact wrench and a 250 lb/ft torque wrench. I wasn't swinging some 6" Chinese made ratchet The other concern is that I needed to drive the car from the shop where I do my work to home and I couldn't risk snapping the bolt. Later today, just for grins I may go tighten it until it either collapses or the bolt snaps.....whichever comes first.
Edit
What the hell...tightened to 82 lb/ft, no deformation of the clamp but.....
I put the Borla X-Piep in my car back when it was available and can offer two tips:
1) test for leaks before putting the trans tunnel brace back in place. As noted above there are many bolts and doing it twice is not fun
2) get new donuts seals. I managed to reuse mine but would have been happier with new ones.
FYI the Borla bolts weren't any better - to me they seemed about 1" too short which made getting the exhaust lined up just a touch tricky.
I plan on purchasing this in the next couple months, did you buy new OEM pipe seals?? Or re-use your current ones? I also have a 2019. Thanks.
Yes, I used new seals. I know many will re-use the old ones but for $10 ea from the dealer, I like new and I like OEM. As shown in my pics up above, the part number is 10354707
One must wonder why such is done so half-a**ed (or worse) in the hardware department? Have they never heard of McMaster-Carr? This ain't eBay.
Amazing isn't it? In bulk (seems reasonable they could use the same clamps and bolts for more than just their Corvette products), I bet we're talking $30 @ cost. Pretty sure that most people would be more than willing to pay $30 more on a $400+ pipe for the much better quality hardware.
I think I have my old C6 Z06 OEM clamps. I'll have to dig one out and take a pic next to what came with the AWE pipe.
I put the Borla X-Piep in my car back when it was available and can offer two tips:
1) test for leaks before putting the trans tunnel brace back in place. As noted above there are many bolts and doing it twice is not fun
2) get new donuts seals. I managed to reuse mine but would have been happier with new ones.
FYI the Borla bolts weren't any better - to me they seemed about 1" too short which made getting the exhaust lined up just a touch tricky.
Exactly right! And when you check for leaks at the cats, don't be fooled by air blowing out of the bellhousing on the M7 cars
My two band clamps are coming in two different shipments so I only got one today Installed it anyway and it formed up correctly with the pipes and no leaks Kind of a PIA since I'm in my condo garage, but with LA traffic it's far easier/quicker than driving to the shop!
Brand of clamp I used Made in the USA Installed and torqued to 45 lb/ft. Leak free
Comparison of AWE clamp to what I had on my Z06 exhaust conversion on my 2013 Grand Sport. The 2019 clamp is still spot welded to the OEM intermediate pipe so using the 2013 Z clamp (which is identical except for the C6 Z having 3" piping) for comparison was easier.
If you're working on a C6 GS and installing the C6 Z exhaust. As stated in my post, I used the C6 Z clamp for comparative purposes to illustrate the difference in quality between the OEM clamps and the clamps provided by AWE.
I was talking to an installer around here about the AWE last week while they were having their holiday sale. He said the exact same thing about the HW shipped with it and that they typically have to do some extra work to remove the exhaust leaks. They've installed it on a couple hundred C7s so they aren't newbs and they do tons of Maggie swaps, pulley/tune, blah blah blah for the C6/C7 guys around here. What they do is just weld it on but will spot-weld if they can to remove the exhaust leaks. Not sure I like that in case I need to go back to stock so it's nice to know about the Torctite clamp. I'll have to ask him about that next time I see him. Great write-up, OP!
My two band clamps are coming in two different shipments so I only got one today Installed it anyway and it formed up correctly with the pipes and no leaks Kind of a PIA since I'm in my condo garage, but with LA traffic it's far easier/quicker than driving to the shop!
Brand of clamp I used Made in the USA Installed and torqued to 45 lb/ft. Leak free
Comparison of AWE clamp to what I had on my Z06 exhaust conversion on my 2013 Grand Sport. The 2019 clamp is still spot welded to the OEM intermediate pipe so using the 2013 Z clamp (which is identical except for the C6 Z having 3" piping) for comparison was easier.
Do you have the part number and where you bought the clamps? Thanks
AWE X-Pipe....some observations
Installed it anyway and it formed up correctly with the pipes and no leaks 
