The stock Corvette exhaust system works well and sounds pretty good. Actually, it's sounds polite and politically correct. From my first test drive, I thought that the exhaust note was a little weak, even under wide open throttle. Heck, my Mustang's stock exhaust (gasp!) had more grunt. Not being a civilized type of person, I went looking for replacement options.
Corsa makes the exhaust system for the Corvette Indy Pace Car. I talked to people about DynoMax, Flow Master, B&B and all the others. My biggest gripe about aftermarket systems was the exhaust drone during cruise. Resonance is a gremlin that many manufacturers try to eliminate but to my knowledge, many aren't successful. During my research, one thing I kept hearing was how wonderful the Corsa system was at cruise speed. People also told me that it was an animal at full throttle and had a wicked snap crackle pop when you let off. That was enough for me! I placed an order with C5 Concepts and waited my gleaming stainless steel wonder to arrive.
One other thing... Corsa makes two systems, the Indy and the Touring. From what I understand, the Touring system is quieter all around. So, what's the point?
It helps an immeasurable amount if you have the car off the ground for an exhaust install. This is always an adventure with the low slung C5. The small space provided by jack stands is better but still a major hassle. I made arrangements with a local shop to come in on a Saturday and use one of their lifts. Well, that was the idea. None of their lifts could accommodate the C5. I was about to give up when I noticed their chassis straightening rack. It was about three feet off the ground and the Corvette rolled right up without scraping. With the car safely off the ground, it was time to make the swap. It's also worth mentioning that you'll want a friend to help.
The Corsa instructions are good but not totally complete. They do have a good complete list of all the tools required. The first thing to do is to remove the four bolts that connect the rear sway bar to the chassis. You can then let the sway bar just swing down out of the way. Next, unbolt rear of the exhaust system from the collectors aft of the catalytic converters. Now remove the bolts that hold the mufflers to the frame (via a rubber mount). If you have an automatic transmission, you'll need to remove the heat shields first. Now, wiggle and squirm and contort the stock pipes over the axle and out from under the car. It may not seem like it, but it is possible.
Now it's time to install the Corsa system. First put the over-axle-pipes in place. Do the mufflers one at a time or you'll stop dropping parts. Put the rubber mounts on the Corsa mufflers and hoist them into place. Put in the bolts loosely and slip the exhaust pipes into place on the mufflers. Now move the flanges together up front and slip the gasket into place. Goop up the bolts with anti-seize and put them all in place. Make them finger tight for now. Make sure you don't get any anti-seize on the stainless steel because it'll stain the finish. Now you're whole system should kind of be hanging by a thread. It's time to tighten everything up and make it look good. This proved to be the hard part. The muffler brackets should be tightened to 37 foot pounds. Make the flanges reasonably tight. You need to adjust everything so the exhaust pipes are level and so they're not touching any plastic. Start by bolting the flanges up tight. Mine leaked so you might have to use the old gaskets or play with them for a while. Now put the U bolts over the pipes at the mufflers and get them snug. Adjust the mufflers until they're level and the pipes are the same distance away from the plastic of the rear skirt. Make sure the pipes are all the way into the mufflers before tightening them up! Keep tightening and adjusting until everything is lined up at snug. It'll take a little while to get it right but be patient. Be careful not to over tighten the U bolts and shear one of them off. If you take the time, the results will be worth it. When everything is set, swing the sway bar back into place and install the nuts. Torque the upper nuts to 49 foot pounds and the lowers to 70 foot pounds.
After everything is done, fire the engine up and check for leaks. Mine leaked at the flanges and where the pipes enter the mufflers. Putting double gaskets on help at the flanges and the mufflers finally seated on their own. Many people weld the pipes at the mufflers for a solid fit.
One side note. We ran into a little problem due to inattention to what we were doing. My installation partner set the torque wrench to 137 foot pounds instead of 37 foot pounds when I was tightening up the muffler brackets. Needless to say, I busted one of the studs off. This was a bad situation. The studs mount to a plate inside the frame. The only access I could see was by taking off the entire rear clip. Being lazy (and inventive) I came up with a strange solution. I moved the broken stud out of the way and used a drywall spider anchor to hold the bracket in place. It's not a cheesy as it sounds. The mount is very solid and hasn't loosened with time. The moral of the story? Be careful and pay attention to what you are doing.
Was it worth it? Yes! I like the way the Corsa Indy system sounds. It's sounds like a big block motorboat at idle and a screaming demon at wide open throttle. Every police office within a two mile radius will hear it when you open her up so be careful. Instead of a mellow burble when you let off the throttle, the Corsa snap, crackle and pop like a thunderstorm. The sound is very distinctive and very cool. Best of all, there is no annoying drone when cruising down the road. As far as horsepower gains? There will probably be a little bit but the stock exhaust was pretty up to the task. Who knows, maybe the Corsa combined with everything else will be the last little bit I need to get into the high 12's!
Return to Mike's Corvette C5 Home Page