I did a thing.

[—Bryan—]

Crinkle red valve covers are just the only way to go. Period.

[— kung fu jesus —]

I am surprised that this wasn't already done. I have the Tein ones so I probably overpaid for the Tein green but I absolutely love them. No drilling and the only thing I had to do was add a washer on the car side of the strut because it was rubbing slightly on the inside fender. But the hood actually goes higher than when I had the OEM hood prop.

The RSpeed lifts are bolt on, too. I just got lazy with the impact drill and zipped in one of the ball studs to oblivion.

They also lift the hood higher than the prop. Adding these was on the list, I just kept forgetting to go get them. R*Speed is about 30 minutes from me on a good day, most of the time it’s longer. ;)

[— kung fu jesus —]

Not knowing how old the filter was on the intake, I thought it would be a good idea to replace it. This car came with a Racing Beat CAI, but the filter wasn’t original. It was an AEM dry filter. All I have done to this intake was swap the NB1 OE crossover with an NB2 for the Helmholtz chamber on it.

After removing the filter, I could see that it needed cleaning and that the flange was too big for the intake. The previous owner spanned this difference by using foam tape on the CAI elbow and wrapping it with electrical tape.

Ok, not horrible but let’s sort it out.

The CAI elbow is a little oddly profiled at the end, but a 3.25” (83mm) flange works. The previous one was 3.5” (89mm).

I wanted to replace it with another dry filter so I looked around at AFe, AEM, and others. I have been happy with AEM products in the past so I used their online search filter to, erm...search for a filter.

I went with the AEM 21-2110DK. There is a slightly cheaper version that is white and I *think* has one less layer, but RED..must be better, right?



Additionally, I think I read the old one can be cleaned and reused, but I’ll have to look into that again.

In the meantime, the filter arrived soon enough. Sealed and boxed, it’s quite similar to the one it is replacing. I had also found out the surface area of this is very similar to the original one that comes with this CAI.









I shook the filter to make sure there were no foreign objects to be introduced into the intake and some bits of flashing fell out. Not uncommon, it’s just rubber or silicone from the moulding process.



I had a little issue getting the supplied clamp to keep from slipping off the flange, so I wiped flange down and used the clamp from the other filter, worked fine and job done.



Oh, and STICKERS!

[— kung fu jesus —]

It’s been a while since I took a drive just for the sake of driving. I considered doing a day trip to Robbinsville, NC, but I suspected everyone and their mother will be around there for Independence Day. I decided to keep it more local.

I took all the backroads to Atlanta Motorsports Park. Being *just* on the edge of the Appalachian foothills, it’s a lot of nice 2-lane with elevation changes. There are a lot of horse farms out that way, so I just rolled along in a general direction knowing I would eventually hit the old state highway AMP is near.

Surprisingly, there was little traffic and what traffic there was moved swiftly and above the posted limits. I was also surprised how many new roundabouts were out there, considering it’s semi-rural (to me), so that helped keep the flow steady and fun. It’s a neuveau riche area out there, so I’m sure the ‘90s hip hop emanating from my 21 year old shitbox was a stellar addition to the countryside. Don’t worry, I wore earplugs.

I made it to AMP to find it nearly empty, so I stretched my legs, watched a pair of McLarens turn some lazy laps, took some pics and headed out.





This SVO Mustang was in the personnel parking area.














I decided to take the backroads from AMP to Road Atlanta, traveling around the north side of Lake Lanier. It was busy, as expected, with a lot of people trying to launch their boats for the evening’s festivities. I picked up a C7 Corvette and an FR-S breaking away from traffic. We were clipping along really well, but perhaps I was driving more spiritedly than they wanted and they both fell away about 15-20 minutes later.

About 5 miles from Road Atlanta, traffic thickened, so I peeled off, grabbed some lunch to go and took the back roads back home.

Really very pleasant, about 2.5 hours. The car feels good, and I like the MSM cloth seats more for this. Not missing the leather MSM seats at_all.

[—Bryan—]

My goodness, this car is gorgeous.

[— kung fu jesus —]

Thanks Bryan! Your OEM+ is an inspiration.

[— kung fu jesus —]

I have been wanting to try to see if stuffing the trunk tunnels does anything for insulating road noise.

I had a fair bit of SFI-rated flame resistant upholstery foam from a time when my BA had Lotus seats, so I thought this would be a great material to use.



I eyeballed the size of the tunnels and cut squares with scissors roughly to fit. I worked it as far forward as it would go, which Was all the way to the bulkhead behind the seats. I ‘opened’ it up and felt round to make sure it touched all four sides of the tunnel then repeated the process on the driver side.











I had enough to put two layers on each side. I took a quick 1/2 mile ride and it seems to be working. There seems to be less noise coming from behind me. I do have questions if doing this may make the trunk hotter, but I will monitor that.

I may also try positioning the foam further back to isolate the holes cut for the rear rollbar legs.

[— kung fu jesus —]

Ok, ok... writing that post and looking at the images sparked an idea, and one that worked very well!

So, with the oversized foam squares all the way forward to the cabin bulkhead, I’m not addressing the holes cut in the parcel shelf for the rollbar. That means I’m insulating sound that is already insulated by the parcel shelf carpet, rubber sheeting, and insulation, and also the seats.

Think of it this way, the tunnels are square-ish tubes with the rollbar’s rear legs coming in from the top. Those holes in the top for the legs are basically open holes to the trunk and sounds coming from it.

So, foam I have is 2” thick and medium density. It has resistance when compressed and I oversized them so that resistance pushing out against all sides of the tunnels holds them in place.

I had the right idea, just the wrong execution. To insulate the sound, I need to isolate the holes made for the rollbar legs and make the tunnel chambers smaller to reduce the sound waves. You can still see the holes from the previous post’s picture:


All the red at the top is parcel shelf carpet. Sound can still get through.

If you can think of the rear rollbar legs coming through the parcel shelf and bolting to the tub represented as a “ / “ the new idea is to put one layer of foam in forward of the parcel shelf hole and rollbar leg and behind it, basically like this:

|/|

Each vertical is a foam square oriented vertically in the tunnel, again the diagonal is the rollbar leg coming into the tunnel.

This was easy to do and doesn’t interfere with the rear damper adjusters.


Driver side rear most layer above. The other layer is just forward of the rollbar leg in a similar position.


This is the passenger side.

So, with the tunnel camber reduced and the parcel shelf holes isolated, did it work?

Yes. The sound coming from behind is reduced quite a bit. I do not discern sound from the differential anymore, tire roar is reduced quite a bit. I also do not hear the exhaust nearly as much either.

I will see how this does over time.

[—Bryan—]

Now that I think about it...I pulled out some of the rags I had packed into my tunnels (never know when you'll just need some rags), and noticed new noises when I backed the car up...

[— kung fu jesus —]

The tunnels are basically resonance chambers. I suspect in an instance like this they may be acting like megaphones from the chamber that is the trunk. Sure, the trunk liner, parcel shelf carpet and insulation help soften this a little, but it’s still letting a lot of noise in, especially with the top up, or in my case a hardtop. The rear glass is reflecting that sound back at you .

[— kung fu jesus —]

Bonus shots from AMP, nehi versions.






Happy to report the tunnel baffling has made a marked improvement reducing interior noise. I took a short drive around town including about 10 highway miles to confirm.

[lifebyevan]

I love the sound isolation idea, seems very effective given the materials you used! keep up the good work.

[— kung fu jesus —]

I downloaded a decibel meter app. I will try to see if I can replicate conditions exact with and without the baffles to see if there is a difference.

[—Bryan—]

I've probably already asked, but what do you have around the cut metal on your package shelf (where the roll bar's legs go down)? Is it just some hose cut in half?

[— kung fu jesus —]

I've probably already asked, but what do you have around the cut metal on your package shelf (where the roll bar's legs go down)? Is it just some hose cut in half?

https://mazdaroadster.net/showthread...l=1#post216203

this self-adhesive c-channel.