Birddogtwo

Last Friday I finally got my car (96 LT4) out of winter storage. In December I bought myself Melrose ceramic coated Smooth Flow Headers and the exhaust back to the mufflers. In February I ordered a set of B&B C4 Fusion mufflers. The mufflers took 5 weeks to arrive. So now I was ready to get started with the installation. Saturday I stripped off the old exhaust including the manifolds.

The manifold is where I ran into my first problem. No my second problem actually, the first being the #@$%? nut on the drivers side cat bracket. I spent 2 hours messing with it before admitting defeat and cutting the bracket off with a Ryobi battery powered saws all . I used a Mapp gas torch to remove the secondary air tube and only succeeded in butchering the flare nut. I took it to a local muffler shop and he got it out using an oxy/acetylene torch. That was the good news. The bad news was it left the threads in the manifold :>( No problem I'll buy a new one... wrong! The pipe is no longer made and there appear to be none left in this country. I may have found one in Europe but the company won't answer my emails. My local Corvette mechanic was in Carlisle and tried to find a tube for me but called to say no luck.

Ok so I'll just get a plug and run it into the manifold and delete the air pump. I called Melrose to find out the size of the thread as I could find nothing that fit. It's an 11/16 x 18. Oddly my local Home Depot doesn't have one. Further research here on the forum told me that an M22x1.50 was essentially the same size. That is coincidently the size of a 1995 Dodge Ram 2500 with a Cummins Diesel oil drain plug. I called several parts stores and finally found a parts (NAPA) store that would order the correct the size but there was a catch he had to order a minimum of 5 and didn't want to be stuck with the other 3 so I had to buy 5. At a total cost of $24 and change I think this might be the cheapest thing on my Corvette. I think I'll get 2 of the plugs ceramic coated to match the headers.

The Melrose Headers fit perfectly. They went on without a hitch. The only problem is the exhaust goes from 3 " to 2 1/4 " for the extension pipe between the cats and mufflers then to the 3" mufflers. I should have realized this since the Random Technologies exhaust supplied by Chris at Melrose was made to fit stock mufflers.I had the same muffler shop that tried to remove the air pipe (great guy) bump up the end of the 2 extensions up to 3"which left the wall of the pipe very thin, but allowed me to drive the car today. I'm bringing the car to him on Wednesday to fabricate 2 3" extension pipes.
All in all I fun project. I took it out this afternoon and put @ 50 miles both highway and back roads. No drone sounds deeper and more controlled than it sounded with muffler eliminators. There is not as much sound difference inside the car between the 2 levels of the muffler (mild to wild) as I expected. There is definitely a difference but I thought it would be more. There is no popping on deceleration and really howls when you put your foot in it. I'll have to see how it sounds outside. There seems to be much better throttle response. The thing I'm happiest about is I got it done in time for Mountain Run!

Now I have to figure out what I need delete the air pump and secondary O2sensors so the CES light will go out. I really don't want to buy a program because then I'll start messing around with other things I shouldn't. If your considering doing something like this I say go ahead. It wasn't that hard just a lot of little things to do.
Save the Wave,
Dave

HAD2HAV2

Dave, sounds like going from stock exhaust to modified was a terror due to OBDII controls. Pics. of the new exhaust would be nice.

Birddogtwo

Had to Have,
I was in such a hurry to get this done I didn't take pictures as I went but I'll try to post some pictures after I get the extension pipes squared away. Thanks for the interest.
Dave

1993C4LT1

Did you notice a power increase?

ElisTwoCents

My code went away but I used heated O2 sensors to do so

Birddogtwo

I do have heated O2 sensors. I deleted the secondary sensors because they would be about 4' further back and I didn't want wires hanging everywhere. I called all the dyno shops in NH no one can reprogram a 96. Up to 95 and from 97up but not 96. One guy told me if I wanted to buy him the $500 tool he needed and pay the $450 reprogramming fee he'd do it. I guess I'll have to go with a mail order tune. Since I'm leaving for Mountain Run next Saturday, it will have to wait.

Wednesday I had a muffler shop fabricate 2 new extension pipes so the entire system is 3" now as it should be. The Melrose system is designed to fit stock mufflers so the pipes from the cats to the mufflers are only 2 1/2. The right side is a little crooked. I'm going to make up some heavier hangers today and see if that helps. I have 2 low clearance areas that vibrate on left turns I'll try to get pics of those and post them. I would have posted the pictures of the system off the car sooner if I realized how easy it was. Maybe I'll get wild and crazy and try to take video so you guys can hear it.

Overall I'm happy with the system. I should be at the cost. The instruction sheet B&B sent was for a C6 so I had to change things up a bit. Instead of putting the control box in the trunk, I put it behind the rear plate. I didn't want it in the hatch area where it might get bumped. Putting the electrical in and attaching it to the fuse box required minor Dremeling to make it all fit. Again nothing was all that difficult just time consuming.

My battery went this week. It's been in the car for the 4 years I've owned it and who knows how long before that so I guess I was overdue.

ghoastrider1

gotta wonder how much that x pipe kills the drone.

Birddogtwo

I'm sure it plays a part. I think the system design overall is what prevents or diminishes drone. I was lugging it a bit up a hill today in 4th and got resonance but I had to work at it .
I have the mufflers as far back as I can and the tail pipes are flush with the valance of the bumper you can't really even see the tail pipes which is a shame considering how nice they are. I suspect it's a C6 kit with a different inlets. I was talking to Mike Boat about the Fusions last year at Carlisle. He told me they were trying to use oval Mufflers for the C4s but were having some problems. I guess this is the solution. I also wish the tails came out of the mufflers lower so I could have tucked the mufflers up more.
Overall I'm happy with them. Still loud and very deep with the valves closed but hellatious with the valves open.

1993C4LT1

Birddogtwo

I always thought that of the line it took more RPMs than it should to get going. More a torque thing. In fact I was worried about losing torque with the 1.75 tubes. It actually launches more easily now than before. I haven't really gotten on it but I would say it "feels" like more power and that may be due to keeping it in lower gear than before because it sounds so good.

1993C4LT1

Awesome, thanks!