KJL

I recently removed my exhaust and was surprised to see the after market exhaust system is actually a smaller diameter then stock. I have stainless works headers into high flow cats. From here there is a reducer to a smaller diameter pipes approx 2.5" OD in to resonator and out through what appear to be corsa mufflers and dual tips. There is no name on the mufflers, just the tips. Whole system looks to be stainless. I like the sound but concerned about the reduced diameter robbing power from the engine. Are there systems that are full diameter from the header collectors

ZR1Bob

That is a Corsa system. You are correct that it is slightly smaller than stock in pipe diameter at 2-1/2". However the mufflers are straight through and represent a 10-15 HP improvement over stock mufflers. Marc Haibeck's extensive dyno testing over the years has repeatedly shown the Corsa to produce the greatest power increases over stock and without any resonance to speak of. At lower rpms they effectively eliminate the resonance with their "Quarter Wave Tuners" (Helmholtz resonators) like the stock system does, but at higher rpms both the resonator and mufflers are straight through for maximum power. A great system. Back in the 90s I tested a half dozen system extensively, including dyno testing, and ended up with Corsas for most of the years I owned ZR-1s. Until I finally switched back to a stock 95 exhaust system with cutouts ahead of the mufflers when, in my old age, I decided I wanted a little peace and quiet most of the time. . --Bob

KJL

Thanks for the reply. I like the way the system sounds. It was on the car when I purchased it. The cutouts that Marc offers look like a lot of fun. You can adjust to whatever sound you are looking for or power.

ZR1Bob

That's what I liked about the cutouts, plus the relative quiet of the stock system on a long trip. Marc's website still shows the cutouts in the mididle requiring the removal of the spare tire and carrier. I did that first but then had Marc switch them to just in front of the mufflers and reinstalled the carrier and spare. Pics in my albums section if you want to see them.--Bob

KJL

Too bad he doesn't offer it as a kit....I would love to go conservative on my C3 434 with the cut-outs.

ZR1Bob

You can get them yourself from Summit and others. Quick Time Performance electric cutouts. Go to their webpage to check out the alternatives. Any competent speed shop could weld them up in front of the mufflers. If you actually go that way and want my take on a switch, I will send you my install pics of a rocker switch hidden under the carpet. Or they are probably here or on the ZR1 Net Registry somewhere if you search.--Bob

jss06c6

I'm running stainless works front to back. Full diameter all the way. Very happy with this setup.