I’m trying to install a Sharkwerks centre muffler bypass and either the 6 flange bolts that hold the muffler to the cats are sacrificial anodes or someone at some point rounded off the nuts. I soaked everything with penetrating lubricant before I got to work and there’s no way I’m getting those bolts off without drilling and/or cutting them off. The bottom 2 bolts on each side won’t be that hard, but the top ones will be a PIA.

I was going to bring it into a custom exhaust shop to have them do it given the condition of the nuts but I find myself with considerably more time on my hands these days so I’ll take run at it. Any tips for getting to those top bolts?

 

Allows you to get up around to that top bolt/nut...




Karl.

 

Remove the rear bumper (which is an easy task), then the flange bolts are right in front of you for easy access. Your tool options for removal vastly increase.

 

I did as Wolfk suggested and removed the rear bumper as well. Top bolts were still not easy but I was able to get on them with a combination of wrenches, a 1/4" drive socket with a swivel adapter and some extensions. If the nuts are completely rounded off you will need to cut them off with a dremel and cutoff disc, then punch the studs out with a hammer and punch, then replace the studs with bolts.

 

Thanks for the tips. Bumper will need to come off and the bolts cut.

 

+1.... some came off fine, others just torqued off flush, and then my buddy hit one with a DeWalt grinder and then swung a hammer and punch... the bolts are pressed in and they will fly forward. Replace with stainless.

Peace
Bruce in Philly

 

Remove bumper for easy access
Break flush or cut off
Use a punch and hammer to knock through the broken studs
If the studs give you a hard time, heat them up with a little torch they'll pop right out. However *wear a thick glove and watch where those hot bolts go, grab them and put them somewhere safe to cool off*

We also have center bypass pipes (and side mufflers) for 997.2 if anyone is interested. Headers are coming soon

Best regards,
John Gaydos

 

Anyone know how much weight you lose with the center muffler bypass? Thanks

 

net is about 9 lbs savings.

https://www.sharkwerks.com/exhaust/p...4s-gts-SHAX193

Peace
Bruce in Philly

 

Hardware store stainless bolts and nuts are not the same as 316 stainless steel hardware for exhaust systems and will fail/ gall more often than just some good grade 8 nuts and bolts. Using anti-seize is a good idea what ever you use. Cheers

 

Thanks for install tips. Next on my to do list

 

Definitely agree...

 

Definitely makes the job easier when you remove the rear bumper. I did this exact job on my '10 C4S and it was about 2 hours start to finish. I would also recommend taking photos of the stock exhaust and brackets and their positions before you touch anything. Good luck.

 

i didn't believe in what everybody was advising about taking the bumper off until I was stuck when I tried to do without taking the bumper off myself...

 

Everyone here has some good tips, but they're leading you down the wrong path. I've been in this situation before and, trust me, you don't want to have to drill out the bolts. This is a big pain in the ***. You also don't need to remove your rear bumper. Here is a definitely step-by-step on how you can easily remove the bolts.

1. For the easy to access bolts, use a 6 POINT socket to TIGHTEN them until they break. You do not want to use a 12 point socket as you may round the bolt before it snaps.
2. To reach the top bolts, don't use an S wrench. Instead, use a universal joint, extension, and ratchet as shown in this photo. Again, TIGHTEN the bolt and snap it off.
   
   
   
3. After snapping the bolts, you'll be able to remove the center muffler.
4. For the remaining studs, take a big hammer and whack them out. If they won't come out, buy this ball joint remover tool to press out the remaining stud.
5. Be sure to replace the fasteners with a material that is resistant to corrosion.

Hope this helps. And if you're interested in cutting and drilling, here's my experience (see 2:37 in video).