AtomicZ_Eric

Hello forum members! This exhaust install DIY is my first and I hope it is helpful to those attempting to install their own aftermarket exhuasts. This is not only meant to be a "how to," but also (and perhaps more importantly) a "how NOT to." I will tell you all my mistakes and problems and how I solved them. This should take 3-4 hours... Not the 10+ I required. Hopefully you find something in here helpful for your installation. A few notes:

+ I am not a professional mechanic. Follow my advice at your own risk.
+ I installed a Borla ATAK over the axle system (p/n 11822), but the install is similar for nearly all C6 base, GS, Z06, & ZR1 cat-back systems. I also took a look at some Corsa directions which were very similar. At the very least this guide could help you formulate your plan for your system.
+ Borla's directions were very clear and easy to follow. I followed them nearly to the letter with a few noted exceptions below. I will use their instructions as the basis for this DIY.
- Disassembly #8: I removed the hanger assembly.
- Assebmly #2 : I flipped the oder of the H-pipe and over the axle system.
+ I will note in the number in Borla's directions.

+ If you do not have access to a lift AND do not want to cut your exhaust off, DO NOT attempt this install. In other words: A lift is required to get the car high enough off the ground to drop the OEM exhaust without cutting it off.


Here we go...

Put your vette on jack stands. The photo below shows 4 with only a jack as a back-up. After this photo was taken I added four extra jack stands (2 under the front cross member, and 2 near my work area). Please be safe. An exhaust install to save a couple hundred bucks is not worth a limb or life!


OEM Exhaust Removal Steps 1-9
Step #1
Remove the top 2 bolts and bottom 2 nuts securing the anti-sway bar. Both are 18mm. To remove the bottom 18mm nuts you must use a 15mm wrench to hold the bolt they're attached to to prevent it from spinning. Leave the lower bolt in once the nuts are removed.


Step #2
Swing the anti-sway bar down and out of the way.


Step #3
Loosen the clamps securing the OEM over the axle system to the H-pipe. The nut is 15mm.


Step #4
Remove the spring hangers. They're 13mm.


Step #5a
Remove the 15mm bolts and nuts holding the H-pipe flange to the catalytic converters. The nuts take a long time to remove - be patient.

Do not remove the flanges from the stud bolts yet. They will support the from the of the H-pipe.

To clarify my comment in red: Make a mark on "BOTH sides" means to mark both the left and right flanges.

Step #5b
A buddy would be better than a jack stand for supporting the H-pipe.


Step #5c
Remove the flanges, push the H-pipe slightly to the rear and downward to clear the seals.



Step #6
Remove the H-pipe by wiggling it free from the OEM over the axle pipes.


Step #7 (only necessary if you have NPP)
Remove the vacuum lines from each muffler assembly. This was fairly difficult due to the tight space and how snug the rubber lines were gripping the pipe. I used a small flat head screw driver to try to loosen the front of the rubber hose. I don't know if it worked?

The method that worked for me:
Left hand for driver side. Index finger on top. Thumb on bottom. Wiggle off.
Right hand for passenger side. Index finger on top. Thumb on bottom. Wiggle off.

Insert the supplied plugs into the vacuum lines and tuck them into the bumper.

Sorry there are photos of this step. The angle was pretty severe and space was tight.

Step #8
Borla's instructions say to use a spray lubricate to remove the rubber hangers from the metal studs. I tried to remove without a lubricant and they would not budge. The ends of the metal studs appeared to be much larger than the hole in the rubber hanger.

Instead I removed the 4 hanger assemblies. They are each connected to the rear of the car with a 13mm bolt. Removing the rubber hangers later, once the exhaust is off the car, was MUCH MUCH MUCH easier for me.


Step #9 and #10 - Remove the muffler assemblies...
With a lift:
I did not perform this method because I did not have a lift. It appears the exhaust rotates about the axle, with some wiggling, to get it out. There are various youtube videos that show this process taking place.

Spoiler: There seems to be some trick to getting it free. Even after cutting my exhaust off I could not get the over the axle pipe to come out through the rear of the car, no matter what I tried. Please read on for warnings about yanking the OEM exhaust out, and what damage it can cause.

Without a lift:
I had to cut the OEM exhaust off to remove it. The car was not high enough in the air to rotate the OEM system off. Unlike Borla, Corsa, etc. the OEM mufflers & over the axle pipe is ONE ASSEMBLY that does not come apart. Rotating it off requires a lot of ground clearance. I nearly dropped the car trying to raise it high enough to get the OEM exhaust off (I may detail my foolishness in a follow-up post).

DO NOT, under any circumstances, try to raise your car that high with jacks + jack stands. IT WILL NOT WORK. YOU WILL LIKELY DROP THE CAR AND HURT OR KILL YOURSELF.



I used a hack saw to cut the OEM exhaust off. I made marks along the cutting path so it can be welded back together properly - albeit 1/32" shorter. I never planned to sell my OEM exhaust or get any value from it, so cutting it was no concern to me. The marks are necessary so that the pipe can be welded back together with the proper orientation.







Now this may shock you - If I were doing this again AND had access to a lift, I would still cut the OEM exhaust off. Above the axle there are a lot of delicate items: electronics, brake lines, fluid lines, etc. After watching a couple videos of people wiggling, tugging, and pulling the OEM exhaust out, I had to wonder, "Did any damage occur?"

Even after cutting the OEM mufflers free from the over the axle pipe, I could not get the pipe out through the rear of the car - in what I consider I safe manner. Although I'm an electrical engineer and consider myself mechanically inclined, I am not a certified mechanic or exhaust specialist. So take my advice with a grain of salt. However, with the mufflers cut free, the over the axle pipe slid VERY EASILY and SAFELY down and out to the front of the car.

Below are some photos showing what is near the removal path of the OEM exhaust.










Perhaps there's some "trick" or angle that I don't have the experience to perform. Just keep this info in mind if you take your vette to a random muffler shop and have a guy tugging away at your OEM exhaust to get it out.



New Exhaust Install Preface
The general flow of the entire process:
Remove H-pipe --> Remove OEM muffler assembly
Then
Install aftermarket H-pipe --> Over the axle pipe --> Muffler assembly

I struggled to install the system with this order. I needed to twist the driver's side over the axle pipe to get it into the muffler assembly. This was not possible b/c it was already installed to the H-pipe.

To me, it makes sense to put things together in the REVERSE they were taken off. In other words, work backwards. If the mufflers were the last item you removed, then it should be the first thing you'd put on. Almost like "rewinding" the install (for those still familiar with VHS tapes)

My flow for the entire process:
Remove H-pipe --> Remove OEM muffler assembly
Then
Install muffler assembly --> Over the axle pipe --> H-pipe or X-pipe.

So Borla's steps
1,2,3,4,5,6.... I have modified to
4,3,2,1,5,6....

Also would like to note that a particular Corsa set of directions I viewed matched the Borla install flow (i.e. H-pipe / X-pipe first). I still like mine better.

New Exhaust Install Steps 1-9
Before you begin:
Test fit your new exhaust parts on the bench and make sure everything goes together OK. Inspect all electronics, plug connectors back in if you removed them, inspect brake lines, etc. My left over the axle pipe was a tighter fit into the muffler assembly, so I decided to install that first when it was time for the step. DON'T FORGET TO INSTALL THE HANGER ASSEMBLIES!!!


Eric's Step #1. (Borla's step #4)
Have a friend help lift the new muffler assembly into position under the rear of the car. Insert the hanger studs into the rubber hangers. Have a friend help with this. Did I mention to have a friend help? I did this alone and it was very awkward.



(Note: If you were to follow Borla's install order, not only would you have to lift the muffler assembly into place, BUT ALSO insert the over the axle pipes. That's why I like my method better! )


Eric's Step #2-3. (Borla's step #3-2)
Slide the Accuseal clamps that came with the kit onto the muffler assembly with the proper orientation shown below. To clarify the photos and my comments - the clamping end should be toward the passenger side (right).

Take each over the axle pipe and maneuver it over the axle into the muffler assembly. My passenger side slid in no problem. The driver side required a little twisting - good thing you didn't already install the H-pipe / X-pipe, right???










Eric's Step #4. (Borla's step #1)
Reinstall the H-pipe. Or, if you have a cat-back system this is where you would install the X-pipe that came with your system. The procedure should be similar.

The photo is pretty self-explanatory. You may notice that this is a photo I used before with the OEM system (I forgot to take a photo with the new pipes). Don't forget the spring hangers.


Don't forget to line up the marks you made during the removal process!



Eric & Borla's Step #5.
Check exhaust system for proper clearance an alignment.

Step #6.
When tightening everything up start at the front and work backwards. Tighten the H-pipe or X-pipe first. Torque bolts / nuts to 35-40 ft. lbs. Try to tighten them evenly - i.e. don't torque the bolt down first and then the nut. That would result in the flange not applying equal pressure and the seal and likely leaking. I guess this goes without saying, but just a reminder. We all make mistakes sometimes.

Next tighten the Accuseal clamps 32-35 ft. lbs. where the over the axle pipes fit into the H/X-pipe. Next are the Accuseal clamps where securing the over the axle pipes into the muffler assembly.

If I recall correctly I could not get my torque wrench in there, so you may have to do this section by feel. Also, make sure that the Accuseal clamp opening is not over the notches.

Step #7.
Reinstall the anti-sway bar. Torque top bolts to 45-49 ft. lbs. Torque the lower nuts to 65-70 ft. lbs.

Step #8.
Before starting your vette be sure to perform one last check of all clamps, seals, hoses, spring hangers, etc.

Step #9.
Start vehicle and check for any leaks, rattles, etc. Fix if any exist. None existed for me, so I was good to go.




Lower the car and go on a test drive. Depress the throttle fully and enjoy the fruits of your labor. Corsa directions recommend getting the car back in the air and double checking everything is still tight after a test drive. This makes sense. I didn't do it, but will check next time I have her up for a fluid change.

CONGRATULATIONS!!!
I hope this guide has helped you work through your exhaust install. Please remember to take your time and be safe.

vig1116

great write up!! I installed my corsa sports last week and it was pretty easy. The only thing i would say different about your write up is, (maybe it's different cause you have a Z06, mine is base coupe), but i didn't have to cut the factory pipes, they just slid out once everything else was removed. I didn't read it all so i don't know if you said it, but how long did it take you? Mine was a little less than 3 hours, but that was my first time doing an exhaust, and i took my time. It also includes all the clean up after...

AORoads

Besides being a great write up with pics, I'm impressed by the little blue and green boxes with text. I know----really simple stuff, but not for me!

I think I'll copy this to my files. Maybe ask the mods if they want this in a tech or gen sticky????

Looks good and how does it sound? I have to read the very end of your report.

LFZ

If you drop the rear cradle and take off the heat shield...it gives you enough room to pull that passenger side out. Just 4 bolts hold it... Very easy to drop and you don't have to cut the pipe and still do it on jack stands.

Rich Mickol

Excellent and informative write-up. Thanks for taking the time.

42Chevy

Great write up. Thank you.

loudvolvo

If you can get the car high enough safely you do not have to cut anything. I removed mine without cutting the pipes.

a couple other tips that may help ppl...

-when pulling the old system out wrap masking tape around the end of the pipe that goes into the h-pipe so it wont cut anything.

-wrap exhaust tips with masking tape to avoid scratches.

-when installing new system put anti-seize on pipes before puttin on h-pipe

AtomicZ_Eric

Thanks everyone for the replies. I really did enjoy making this thread. It did take a bit of time, but if it saves a few people a few hours... well then it was worth it.

Took me about 1.5 hours to get to the point of taking the old exhaust out, and about 2.5 hours to install (including having to reverse Borla's process). And about 7 hours trying and failing to get the car high enough to get the exhaust off w/o cutting

I could do this again in about 3 hours now that I have the process figured out.

Thanks for the compliment. I hope the admins are able to add this to a DIY sticky. It would be nice to get "immortalized."

I'm not sure what you mean by "rear cradle." Is that part of the rear suspension / cross member? It would be interesting to see this method. Nothing struck me as obvious for removal :-/ Perhaps just my inexperience. Nonetheless it would be an interesting method to solving the height problem.

It was my pleasure. I've gleaned so much from these forums I'm happy to have had the opportunity to give back this little bit.



Great advice with the masking tape. That never occurred to me. I'm sure that would save a lot of cuts / scrapes if someone didn't have gloves handy.

vig1116

The only thing needed to move out of the way for me was the sway bar like you did, i didn't touch any heat shields. Also, after looking at your pics again, i realized i raised the back of the car A LOT higher than you had it. I left the front alone and raised the back high enough to get the rhino ramps under the tires and leave them there in case of jack failure... My front air dams were about a millimeter off the ground, that's how high the back was..... Either way, great job. I think the corsas were a lot easier than the borla, just from the looks.

AtomicZ_Eric

That's great advice. I don't have Rhino Ramps, otherwise I may have given it a try. However, my pictures may be a bit misleading - my car was pretty high off the ground. If the front jack stands weren't supporting the front I'm fairly confident saying the front of my car would be crushed. Obviously it's not safe to use jack stands in the manner.

If I ever do this again (maybe on my dad's car?) I'll give this method some consideration. There certainly seems to be many ways to skin a cat.

su8pack1

Good job.

AtomicZ_Eric

Thank you very much. Please refer friends to this post if they are looking for ideas to install their own exhaust.

Top_Fuel

Great write-up!

As has been pointed out, if you back the car up onto some Rhino Ramps so the back tires are about 10" off the ground, the factory mufflers/pipes will come out in 1 piece. See pic below.



^ I did mine this way. I just had my front tires sitting on a piece of 2x12 lumber. I didn't jack up the front of my car with any stands or anything.

The only additional thing you may have to do is to unbolt the 2 stabilizer bar mounts where it is held to the cradle. This will allow you to rotate the stabilizer bar down out of the way. Some times the mufflers will get hung up on this bar as you are trying to fight them out of the car. You do not have to remove the bar from the car (leave the end bolts on the bar connected!). See pics below...

LFZ

So how do those Borlas sound?? I had the stingers on my Z...loved the sound, but couldn't stand the interior noise. It was so bad..it was rattling the panels.

1bdvet

Nice job!

AtomicZ_Eric

They sound absolutely awesome! The tone is wonderful. No drone. And the rumble doesn't appear to make any interior bits rattle. I've very satisfied so far. I plan to make a video review that I will post soon.

Thank you sir.

AtomicZ_Eric

I'm thinking there may be a significant difference in the exhausts of the base / GS and the Z's (other than the diameter). By the look of your photo I did have my rear end up about that high. And the exhaust wasn't even close to coming out. There may be an angle you're able to twist / wiggle that I can't. I looked at a couple vids online of OEM exhaust removal from Z's and they seemed to be pretty tight. I'd still cut the Z's exhaust to protect all the delicate items in the removal path, for the reasons stated in the DIY.

Nonetheless this is supposed to be somewhat generic, so if you were able to accomplish the removal without cutting then that is awesome, and thank you for adding the info. I'm sure many people will find this helpful.

Top_Fuel

You may be on to something there. After I posted I took a second look before I realized you had a Z06. That might be an issue. But there are lots of people selling Z06 mufflers that haven't been cut...so I wonder if the car just has to be up a lot higher or something?

N2TU

Wow!...

What a super write-up! Thanks for taking the time and effort to document this for us...

AtomicZ_Eric

I know there is a 0.5" diameter difference, but perhaps other clearance issues are caused by transmission, rear cradle / cross member, etc. differences? It can definitely be done (w/o cutting) if one has access to a lift. Again, there are lots of delicate items up there, so take care before just yanking the OEM system out.