Well now. That is something I was not expecting. The heat that radiates from the center console area of my Miata. Ok, the primary shift boot that mounts to the floor is bad. It is a square piece of rubber with a round hole in it. And there is a corresponding round piece of rubber that is on the shift lever. And an air gap in-between them. I will need this as the 1st step. And I might as well get the little felt pad that goes under it. The boot is part # NA01-64-481B and the felt pad is # FB01-64-495.
Next (or maybe should be 1st?) would be any heat shields on the floor or exhaust. When I look at the Mazda parts catalog it looks like the heat shields came with the down pipe and catastrophic converter. I assume those are not sold separately. With one exception, I cannot find heat shields for the floor that would insulate the floor from the exhaust. Are there heat shields on the underside of the floor?
That big shift boot is the primary contributor to your heat. It's a consumable on Miatas. Your favorite Miata parts vendor has one made of thicker rubber.
https://flyinmiata.com/products/shifter-boot-large-na-nb
They also stock some upgraded insulation.
https://flyinmiata.com/products/shifter-insulation-kit-na-nb
There is a factory sheetmetal heatshield that sits above the cat. Factory part NA01-56-411, NLA.
Also, make sure you don't have any exhaust leaks. If that flange in the photo Keith posted leaks the tunnel gets so hot it'll melt the plastic housing of a borrowed hand held radio.
Most excellent. I will check for an exhaust leak. I will also order the two parts from FM. I will also get the car in the air and try to fabricate a heat shield if mine is missing.
Thank you both!
I recall a thread on a different forum where people were pirating a junkyard honeycomb exhaust tunnel heat shield from some model of Kia that worked really well in NA/NB Miatas. Try to Google it.
If you want to get hard core about heat management, DEI Floor and Tunnel had a huge effect on the Targa Miata. That's a bit excessive on a mostly-stock drivetrain though, and install is a bit involved :)
Rodan
UltraDork
7/3/24 8:55 a.m.
Having fresh shifter boot/insulation parts is a great start.
Here's some good info on heat shielding for Miatas: https://www.miataturbo.net/race-prep-75/heat-shields-90059/
It looks like the prices have gone up on the Mazda 3 heat shields over the years, but it's still a good option. IIRC, I used the part from a CX-5 (?), found cheap on eBay, with a little extra sheet material from the River store. It made a tremendous difference in interior temps.
Keith Tanner said:
That big shift boot is the primary contributor to your heat. It's a consumable on Miatas. Your favorite Miata parts vendor has one made of thicker rubber.
https://flyinmiata.com/products/shifter-boot-large-na-nb
They also stock some upgraded insulation.
https://flyinmiata.com/products/shifter-insulation-kit-na-nb
There is a factory sheetmetal heatshield that sits above the cat. Factory part NA01-56-411, NLA.
Are we not going to talk about the exhaust manifold?
Interesting read, Rodan. I didn't find the DEI stuff difficult to work with at all, and the adhesive backing meant I didn't have to mess around with drilling/riveting/etc. Cost was $126 and I've still got some left. But this is for a car that pumps 500 hp worth of exhaust heat down the tunnel and has no interior carpet, for a normal Miata I'd be making the stock parts were all in place.
theruleslawyer said:
Keith Tanner said:
That big shift boot is the primary contributor to your heat. It's a consumable on Miatas. Your favorite Miata parts vendor has one made of thicker rubber.
https://flyinmiata.com/products/shifter-boot-large-na-nb
They also stock some upgraded insulation.
https://flyinmiata.com/products/shifter-insulation-kit-na-nb
There is a factory sheetmetal heatshield that sits above the cat. Factory part NA01-56-411, NLA.
Are we not going to talk about the exhaust manifold?
The heatshield on the stock manifold? They have a tendency to crack near the mounting points and cause a buzzing noise, but they don't usually result in cabin heat when removed.
Rodan
UltraDork
7/3/24 12:06 p.m.
In reply to Keith Tanner :
My choice was influenced by hearing complaints about adhesive material failing over time on a track car, but your experience seems to throw some doubt on that. The other factor was being able to mount the material with an air gap, which I think enhances the effectiveness.
For a stockish street car with interior, IMHO the factory stuff is effective enough, but one of the above upgrades would definitely help on a turbo or swapped car.
I spent some time cleaning that tunnel with brake cleaner being the final boss after starting with Simple Green. Also, not all adhesives are created equally so different brands might have different results.
Having an air gap would definitely make it more effective, although that increases install difficulty fairly substantially.
Another yes to replacing that rubber boot. And now that I think about it, I replaced mine 20+ years ago....
In reply to Noddaz :
It's 114 here today...............it simply is not hot out were you are.
Keith Tanner said:
The heatshield on the stock manifold? They have a tendency to crack near the mounting points and cause a buzzing noise, but they don't usually result in cabin heat when removed.
The portion that appears to be made of PVC piping...
theruleslawyer said:
Keith Tanner said:
The heatshield on the stock manifold? They have a tendency to crack near the mounting points and cause a buzzing noise, but they don't usually result in cabin heat when removed.
The portion that appears to be made of PVC piping...
Jet Hot or similar coating.
It's just white ceramic applied by my local powdercoat shop. That's not the most interesting part of it, it's a long tube design with less than 10mm of difference between the longest and shortest runners. Track and dyno proven.
