Possible help on exhaust drone? - ZR-1 Net Registry Forums

XfireZ51 · 04-06-2015

Installing C6Z brakes pretty much makes the stock ZR spare tire worthless. So my spare tire carrier was removed to lower some weight. Didn't have much to do for winter projects, but I thought about a way of reducing exhaust noise intrusion into the hatch area. My hypothesis is that with the tire carrier removed, the hatch floor is pretty much exposed to road and exhaust noise causing a bit of a boomines at certain engine rpms. So I decided to "repurpose" the tire carrier
and bolted it back on, but now rather than holding the spare tire, I'm using layers of fiberglass insulation to soak up resonance that would make its way into the hatch area from underneath. Took the ZR out yesterday for a test drive and doing some datalogging checking results of new Injector Bias values.
Just to refresh everyone, my exhaust has no resonator but it does have an
SW Xpipe after the Watson headers. I do have DynaMax 3" inlet UltraFlows w Z06 exhaust valves and tips installed controlled by a console rocker switch.
I was actually able to drive with the exhaust valves open at cruise without noticing they were open. What I heard was a "purr" coming from around the back of the car and not through the hatch area. At idle, you will hear the exhaust in the cabin but it's mostly the bass note. At cruise, it reminded me of the exhaust note I got w the MagnaFlow cat back system installed, which I liked quite a bit.
Be interesting to have someone else try this and see what their results are like especially if you still keep your spare in the tire carrier.
For now, I'm going to keep running around like this and see if I continue to like it. First impression is that it really helps.

04-06-2015	#1
XfireZ51 Join Date: May 2007 Location: Chicagoland, IL Posts: 9,683	Possible help on exhaust drone? Installing C6Z brakes pretty much makes the stock ZR spare tire worthless. So my spare tire carrier was removed to lower some weight. Didn't have much to do for winter projects, but I thought about a way of reducing exhaust noise intrusion into the hatch area. My hypothesis is that with the tire carrier removed, the hatch floor is pretty much exposed to road and exhaust noise causing a bit of a boomines at certain engine rpms. So I decided to "repurpose" the tire carrier and bolted it back on, but now rather than holding the spare tire, I'm using layers of fiberglass insulation to soak up resonance that would make its way into the hatch area from underneath. Took the ZR out yesterday for a test drive and doing some datalogging checking results of new Injector Bias values. Just to refresh everyone, my exhaust has no resonator but it does have an SW Xpipe after the Watson headers. I do have DynaMax 3" inlet UltraFlows w Z06 exhaust valves and tips installed controlled by a console rocker switch. I was actually able to drive with the exhaust valves open at cruise without noticing they were open. What I heard was a "purr" coming from around the back of the car and not through the hatch area. At idle, you will hear the exhaust in the cabin but it's mostly the bass note. At cruise, it reminded me of the exhaust note I got w the MagnaFlow cat back system installed, which I liked quite a bit. Be interesting to have someone else try this and see what their results are like especially if you still keep your spare in the tire carrier. For now, I'm going to keep running around like this and see if I continue to like it. First impression is that it really helps.