Glad to hear that you're ok. Taking care of your health is extremely important and anything to do with a vital organ is something that should be addressed right away, as you have done. Just glad to hear that you're OK and doing better.

Great work on the exhaust and the intake porting! Should make a bit of a difference and sound amazing!! Excited to see how this turns out!

 

Thanks, it has been a fun little project. Heart disease is a male family tradition going as far back as I can find. I am ahead of the curve and plan on staying that way.

 

Thanks, I am hoping to avoid most of the typical drone but I already had some drone with the gutted main cat stock exhaust. Porting the lower intake will be fun and scary all at the same time. I am hoping the numerous videos on the subject will help keep me out of danger and actually have an impact.

 

I have had three different exhaust systems on my 93. The drone had been awful with the one that came on the car when i bought it and the replacement wasnt much better. Though the second exhaust system, which was a factory cat back exhaust with muffler eliminators, sounded amazing. It was just very loud and the drone was not great. The issue is that I have gutted cats. The car came that way and its been difficult to get a sound that is a good compromise between loud and clean sound with no drone. So, I went back to a stock cat back exhaust and the exhaust is quiet with zero drone. Its pleasant to drive, but just a little too quiet. Maybe I will look for some stock converters and put the exhaust with the muffler eliminators back on. Or just leave it and concentrate on other things that need attention.

 

I really want to make the drone as light as possible but I know that probably won't happen. I don't plan on chasing it too much. The 89 setup with the pre-cats and main cat was probably ok but quiet, mine had the main cat hollowed out and was probably the source of most of the drone. The sound was ok but not great and just loud enough. I really don't want to announce my presence on the road any longer, those days are far behind me. I like somewhat quiet until I step on it and then I want to hear it. A lot of companies claim to offer that but few really do. My old 2001 Silverado had a Gibson system on it and it was just about perfect, that truck really sounded great. Gibson is still in business but I can get Corsa mufflers for just a little more than Gibson, and I may end up doing Corsa mufflers if what I am building is too obnoxious.

 

Corse mufflers would be a great choice! Have you considered a performance high flow converter with a Corsa cat back? Would have a great tone with likely little to no drone and sound good when you lay into it. I'd love to put stock converters on mine and get a Corsa cat back system. I think it would give me exactly the tone I'm wanting. But at the price point, I just can't swing it right now.

 

I feel the same, my only objection is the price, it doesn't make financial sense to put a cat back on a car that cost half of what the car cost. With as little as I drive the car, it would not be wise money spent. If this car were more than just a toy to keep my busy that would be different, but it is just a toy to keep me busy. To add to the fun, I am going to have to wait on any large expenditures for a while, I am going to have medical bills rolling in.

I will know more and make a decision after I get this put back together and see how it sounds. I am still a little too weak to get the headers installed, it is really a pain in rear to get them in place.

 

I agree with that entirely. I find it hard to invest in a Corsa when bills are rolling in and the Corvette is just a toy amd doesn't absolutely need the exhaut. The weather has been so rainy here that I haven't driven any of my Corvettes in weeks. We will get one nice day and then its back to rain.

I hope you are feeling stronger with each day and I wish you the best of luck with your header install. If we were closer I would be more than happy to come by and put them on for you. I'll be excited to hear how the car sounds when you are able to get it together. It may sound amazing with nothing else needed and I'm hoping that is the case for you and that you love the tone!

 

If you were just looking to quiet it down some like the main cat would, have your local muffler shop install some glass packs backwards. I got rid of the single cat on my 84 and put in 2 cheap hi flow cats that were like $40 each online then put in "resonators" ( glass packs ) backwards. I had them install the cats first, I listened to the sound, then the resonators and listened to it again. Nice and quiet when you want it to be and won't break the bank like a name brand system

 

It has been rainy here as well, this was the right time to do this exhaust work as the car wasn't leaving the shop any way. I am getting a little stronger each day, I have avoided any strenuous work until I get the clearance from my cardiologist, which should come tomorrow after our appointment.

In my case, the sound level was never the issue, it was the drone. It could be the drone is reduced enough by adding back in the main cat that I don't need to do anything else. I had actually looked at adding resonators but what I think I will do instead is install some 1/4 wave pipes to go after the specific frequency of the drone should I find it objectionable. I have good enough recording equipment to isolate the offending frequency and it is easily the least expensive method to remove drone. I also have planned on adding some more mass to the rear wheel wells, specifically on the outside between the liner and the wheel well. This will help with road noise primarily but can help lower the level of the droning frequency, the shape of the wheel well is like a drum so adding mass can help lower sound transmission.

This video is one of the better ones that describes the problem and the solution. There should be enough room in the back to add piping.

 

Headers are installed, as is the mid section of the exhaust mated to the factory cat back. I won't say this is an easy task, it isn't, or at least wasn't easy for me. The biggest issue isn't fitment, it is the header bolts, primarily the passenger side on cylinder #2 and #8 where there just isn't enough room for my hands or tools to fit easily. I had to swing the A/C compressor out of the way and that brought it's own issues. I used a combination of the Summit split header bolts, the Hooker supplied bolts and the factory studs to get it to work. Surprisingly the factory bolts all looked good, the threads were nearly perfect, I cleaned the threads where it bolts to the head and see no real issues. I really like the split bolts, other than the need to use a 12 point wrench/socket on them. I hope everything stays tight and I did use red Loctite on all of the bolts but I have concerns about whether that will be effective or not.

The headers installed, copper faced gaskets and a lot of hopes this doesn't leak. I will go back and check the bolts after a few heat cycles. I don't really want to bag on Hooker because these headers are overall very nice, but I had to "massage" almost every primary tube where it left the flange so any of the bolts would actually fit into the hole, this was a source of frustration taking the header in and out to make enough clearance. I did it and expected I would have to massage a couple of them, I did not expect to have to beat on most of them.






I bent up an aluminum heat shield for the MagnaFlow cat for between the top of the cat and the car. It does come with a heat shield already but a little extra won't hurt. I drilled the outer flange and riveted the additional shield on. It came out pretty good.






The aluminum shield for the Y-Pipe also got riveted in place as well as formed so that it can't slip.



I managed to get everything tucked into place but not without some issues I discuss later. The X-Brace will fit with no issues which was a concern with larger piping than what was there originally, I remember I had to really work the factory exhaust to get the X-Brace to fit.



This was a test fitting and I am glad I did numerous test fittings to check fitment and alignment before doing the last few welds. I ended up being about an inch longer than the factory exhaust which I am going to have to adjust for.



I did quite a bit of heat management, this is a DEI starter heat shield that fir perfectly and will hopefully slow down any starter heat soak.






I was concerned with spark plug wires being burned since the pipes are really close to the plug boots in some places. I shopped around for ceramic plug boots and ended up with a set of Dragon Fire 8.5mm wires and ceramic boots. These appear to be a fairly decent set of plug wires, 40 ohms/foot and manufactured well. Time will tell how they hold up but I have a good feeling about them. I also added some DEI spark plug Protect-a-Boot to try and save the wires from burning up. Since I had this all apart I also replace the temp sensor wire in the passenger head. I already had the Mica covered high heat wire and this was the perfect time to do it.






I dropped the whole exhaust not long after I got this car to get the speedo working but I did not really look at it closely. The cat back section is not in good shape, though I had it apart I never really examined it the way I did the mid and engine side, which was in near perfect condition. The rear Y-Pipe is rusted between the exits, I booger welded it closed for now, I have a replacement section coming. It was also really beat up, like really beat up and collapsed in places I don't understand how it could have been beat up. In order to make up the inch over I was, I decided to take that out of the cat-back as it was a good place to get a little extra room. This is when I discovered the true condition of the cat-back. Both mufflers are blown and have large chunks rattling inside that are too large to get out the pipes. I did not discover this before because I never turned the muffles over, I just slid that section to the side. I got a good laugh when I heard all of the loose steel inside rattling around.

I still have the car on jack stands and will give it some heat cycles to help cure the silicone spray and re-apply until I have several coats on. I did add the second O2 sensor for the FiTech system ordered and received the extension harness so I can plug it in but that will have to wait, the pig tail on the harness is tucked into the dash and I am not ready to go that deep into the dash again for a while. This has been a fun little project that isn't finished yet. Once the replacement cat mid section arrives I will be replacing the mufflers, yea, more welding.

 

Awesome thread.

Simply outstanding work, OP.

 

top notch as always!!

 

Thanks, it has been a fun little adventure with more to come. I do have to slow down as my energy level has dropped, as expected, it will take a little time to get back to where I was.

 

slowing down will be difficult, but you know too important not to - energy will come back in time - and the fun will wait for you

 

Everything is waiting for me, lol. I have about 8 acres of grass to cut but it has been way too wet to cut it, and it is a large energy expenditure that I cannot afford, not to mention avoiding the bouncing around my cardiologist suggests I avoid for a while, something about springs and dislocation, lol. Our local high school kid who did a lot of what I couldn't or didn't want to do, has left, gone to college and gotten married. The search for his replacement has been under way for a while, he was a rarity, he liked to work for money.

 

true rarity - absolutely