I agree with Rockit, I have a 95 cab with stock exhaust and mostly hear the sound of the road and wind when the roof is down. I use a boot cover and wind blocker but don't really notice any difference in noise if I don't.
I will also agree with the OP that engine noise is loader when the roof is up. It's not unbearable, just more engine sound and less wind sound. I'm not sure if it comes through the roof or the back seat area, I think it seems to be the rear seat though. My sound deadening blanket looks about the same as yours, no real noticeable problem areas. I have always chalked it up as the nature of the beast.
For comparison my 2000 Boxster has the same level of noise as the 993 when the roof is down but put the roof up and it's almost silent.

Hi! This is very interesting. Why did you have your transmission mount redone? What were your symptoms that required a DMF replacement?

I was surprised by the amount of vibration, but accepted it. Perhaps that’s a symptom I shouldn’t ignore. My clutch catches extremely high, and I feel uneven power for a second when I drop the clutch even after a rev match. I recently had misfire errors fixed with a rebuilt distributor/plugs/coils. This significantly reduced uneven power under load, but I’m still feeling it a surprising amount - more than on my ‘85 3.2. Perhaps it’s time to get the clutch/DMF replaced, and get the transmission mounts checked. I know uneven power can be caused by many things, but the last shop that did the distributor are less experienced with older Porsches, so perhaps they didn’t pick up on other contributing causes. My 3.2 is being worked on at Aldo’s in SF, so I’ll probably take the 993 there with this question as well.

The symptoms I noticed that drove me to do the clutch job were:
- Clutch engaged high in the pedal throw.
- Rattling noise at idle, only evident with the clutch out. Clutch in would silence it.
- Rattle at shutdown, also only evident with the clutch out.
- Occasional clunk when starting out from first gear.

It was all reasonably subtle but to me pointed to a DMF issue. I searched some threads and opinion seems to be that DMF rarely fails in the 993, but I went ahead and cracked it open anyhow. Once inside we found the clutch nearly worn to the end, not much material was left. DMF was failing and had play that shouldn’t have been there. It wasn’t completely broken through yet, but on its way. Transmission mount was cracked and aged. These were all original parts on a 130k mile car, so understandable that they were at the end of their life.

I replaced with a LWF and sprung clutch.

Without going into the improvements from the LWF (which I enjoy) the biggest surprise was the reduction in NVH. I can’t say how much was DMF and how much was the mount, but I’m guessing it was a combination. The trans mount was no longer supple and was likely increasing NVH, similar to if you were to install a stiffer mount which is a known avenue to increasing NVH.

The DMF certainly made noise at idle, so maybe it made noise while driving as well. Since it is rubber centered, if the rubber had failed such that it was up against the stops (metal on metal) it may have been increasing NVH. I’m less sure about that though, since I did replace it with a solid piece (LWF), though perhaps the sprung clutch absorbs some noise now instead. Or maybe this makes no difference at all under load when accelerating, since they are all under quite a bit of pressure.

Not sure... Anyway, the combination made a big difference for me so perhaps you would have a similar experience. I kind of enjoyed the NVH to be honest, it sometimes felt like the engine was in the cabin with me, I could feel every little tingle and vibration. But the lack of ringing ears after a spirited drive is nice.

Fascinating. I had the first gear clunk maybe three times. Did you briefly lose power at the clunk? I will have to experiment with clutch out noise.

Mine has 104K.

With your bad DMF, did you notice very mild hesitation in the first second or two when hitting the throttle? Did this go away after you switched to your LFW and sprung clutch?

Thanks!

Hi Tosha,

I’m betting that you have some wind leaks around the door windows. I just had an 1800 mile round trip holiday roadtrip and I was comfortably listening to podcasts and having conversation at 80mph in my 964 with the top up (and a slightly louder exhaust and rear suspension setup and some other noise-inducing mods).

The top and rear window seals were very UNlikely to have been replaced when your top canvas was replaced. They’re pricey and can usually be adjusted to keep the wind out, but they’re fiddly.

Does a lot of your top-up noise sound like the windows are slightly cracked open? Aka, wind noise? Cabrios can be sealed up, but it takes some work and patience. When you wash the car, does water drip in at the top of the window? If so, adjust the top window seals (remove the rubber trim cover and loosen the screws). Does the back of the window sit against the rear seal with no gaps? If not, you can adjust the rear seals (loosen the nuts behind them). Get a suction cup to stick inside of the window and pull the window tight against the seals from inside the car while someone else is driving at speed on the highway. You should be able to isolate window wind noise easily. Another trick is to put some painters tape along the seams to find the air leaks.

If your top has been replaced, check where the top touches the rear fenders just behind the door windows. There is a ~6” rubber gasket that seals the top to the body which could easily be missing or installed incorrectly. Without it, there is a huge gap under the canvas for wind noise.

Once the wind leaks are sealed up, the rest is down to tire and engine noise. New ps2s should be fairly quiet. The stock 993 exhaust is certainly not loud. Expired engine mounts are common and could be a source noise.

You should always use the boot/cover when the top is down. Otherwise the headliner gets destroyed by the wind in short order. The windstop will make a dramatic difference in top-down wind noise, as with any convertible.

All that said, there is a big difference in road and outside wind noise between 60mph and 80mph. Some of it comes with the territory, but what you’re describing doesn’t “sound” normal. If you have a smartphone, there are several audio spectrum apps that -roughly- measure sound dB. That would be helpful to compare.

Good luck!

I know this was a year ago and you had the car sorted since then, including alignment of the door. Just wanted to say that that gap was definitely WAY out of spec and I’d wager a large part of the wind noise you were experiencing when closed. Glad all’s well now!