Transmission tunnel heat shield (liner?)
 

What transmission tunnel heat shield/sound deadner would you all recommend? I'm thinking about something that would go under the car above the transmission.

I used this in my tranny tunnel. Have to replace it every few years though.
BEGi

Stephanie

Does that block any sound? My enthuza makes me deaf.

I don't know what your exhaust sounds like but try driving with a SD spec miata exhaust for an hour on the highway without 5th great at 70mph. Thats loud. Try it you will be rethinking what you just said. Lol.

Have a great day,
Jared

How will any tranny tunnel material quiet a loud muffler?

Perhaps a quieter or just an additional muffler would be more useful for that purpose.

Heat shield above the tranny would be totally worthless. If you want to block actual heat, it all comes in through the left side of the tranny tunnel, from the downpipe. On a track car with a turbo and no carpets, it will burn your right foot if you aren't careful.

All the noise from your exhaust is coming in through the paper-thin sheetmetal in the trunk, passing through the two huge holes next to the gas tank, and right into the cabin. If you don't believe me, take off your fuel bulkhead cover and see how much louder the car gets.

If the Enthuza is too loud, you should either make it quieter (resonated test pipe, larger muffler) or make your perception of it quieter (earplugs). I used foam-bud headphones for highway drives on a regular basis when I had my catless Enthuza.

I actually do use earplugs and I have a catless enthuza.

So you recommend heat shielding the area where the downpipe is?

OK

It'll block heat, but it's only a problem on track cars. It won't do anything for your loud exhaust.

clean the tunnel really well by the dp. Cut
thermal blanket to fit. use the best 3M adhesive on the well and the thermal blanket. Stick the blanket on the well wall. Your done. You only get one shot at though. I've done this on two miata's SC and Turbo. Worked great.

Not that it helps you much, but this made my feet on a 105* track day feel like my usual 70-80* track days.
Attachment 201640

Coupled with some NACA ducts, I stayed surprisingly cool in 105* weather and the heat on full blast. No bueno for street cars of course. I shove a spray can top in the NACA ducts for normal driving and they leak. They're currently blowing 30* air in my face.

I tryed the in car application didn't do too much for me. For the best results you need to block the heat before it soaks into the floor board.

Like Sav says, lot's of noise comes through the trunk. The Mnet solution is stuff some fiberglass insulation in some plastic bags. Stuff those in the openings behind the fuel tank bulk head cover on either side.

Ooooh I like how cheap and ghetto that is...

This might help:
http://www.targamiata.com/diary.php?UID=519
Keith eventually installed the insulation with some ridiculous waterproof tape (I think he said can even be applied underwater). But I can't find that entry.

instead of using fiberglass, you can just go to a fabric / craft store and pick up pre-assembled bags of pillow stuffing and shove those in there. wont get itchy.

Good idea. And I'll have high frequency absorption while I'm at it. Do you think I should just stuff it in the midpipe and exhaust or should I stuff the downpipe as well? I'm thinking that since I'm increasing the range of the resonant frequencies that my turbo should spool faster throughout the range of the compressor map and be more responsive.

You're joking, correct? If not, stay away from cars.

Since post #12, we've been talking about stuffing bags of stuff behind the seats. There's a spot on either side of the gas tank and chassis that you can stuff something in. There's only a thin piece of sheet metal blocking the cabin from the trunk via those two tunnels, and there's a lot of noise in the trunk from the exhaust.

i think that was sarcasm cuz we hijacked his thread about heat from the tranny tunnel.

I think that's ridiculous. If you did that, they would definetly catch fire. I mean, the fuel tank is right there and what do you think the purpose of fuel is? To burn, dumbass. :jerkit:

Since, it's Chistmas, this is for you:

http://maaadddog.files.wordpress.com...e_gargoyle.jpg

I'm reviving this thread because I'm having issues with heat coming from the transmission tunnel. I came across something that I'm interested in trying

1993 Mazda Miata

Using just the reflectix from home depot

Reflectix 4 ft. x 25 ft. Double Reflective Insulation-BP48025 at The Home Depot

The other question is: what holes from the trunk by the gas tank?

If you just want coolness, just buy the cheaper version of that stuff and stick it under the carpet. Or if you want to knock some sound down to, you can do the entire drivers half of the floor pan with 2-3 pounds worth of cool mat.

I just want less heat, so thanks!

Available at Lowe's for $18:


https://www.miataturbo.net/attachmen...ine=1369742015

Ended up going to Lowe's and bought a 16" x 25ft of Reflectix for $11. The cabin is much cooler than before. I also shoved some of it on the hole next to the tank along with some foam and the cabin is more quite now.

Sorry to bump an old thread, but this is relevant!

Do folks apply that insulation under the carpet or under the car? I'm doing a clutch job soon and was wondering if there was something I could just stick between the transmission and the trans tunnel underneath the engine so I don't have to rip up carpets.

I degreased the underside of the trans tunnel with brake cleaner and applied it there a few years and several track days ago. It hasn't moved. It is really good for reflecting the radiant heat away. And it stands up well to the exhaust heat.

The lowes stuff?

Awesome!

Same here. I used Themo-Tec 13585 adhesive-backed aluminumized fiberglass heat barrier.

@Blackbird does some fancy stuff in the same location with a junkyard OEM heat shield from some other car mounted with an air gap.

https://cimg6.ibsrv.net/gimg/www.mia...510ab718dd.jpg

How much of it did you guys end up needing? 12x24 seems like it wouldn't be enough.

What you want is DEI heat shield. Super sticky and easy to work with, glue won't run. It helped me lower the temperature of the tranny tunnel. I've noticed it right after I bought a miata that the metal in that tunnel would heat up a lot and the whole car would start to get hot quickly. I'm in CA, so when added to high ambient temps - it was quite uncomfortable on long drives. 12x24 is just enough, but could use more for better effect. I've used 2' x 21" in the pic below.

https://cimg1.ibsrv.net/gimg/www.mia...c2f458cc73.jpg

Maybe I'll lay the pad down like you did and buy a roll of tape to go around the edges.

My GF and I were sweating in the car with the AC blasting on a road trip when it was in the 80's.

The Lowes/Frost King insulation really disappointed me with how non-stick it was. Even having cleaned the trans tunnel with brake clean, it had pretty poor adhesion. It also didnt make a night and day difference, but I didn't use it in the area under the dash. I wouldn't trust it outside the cabin, much less hanging upside down right next to the hot exhaust.

Focus more on keeping the heat off of the chassis in the first place by using a better insulation on the outside of the car.

12 inches wide and 15 feet long for under $20, lasts for years and works really well. What else do you need?

I also recommend getting heat shielding around the pipe itself just like it comes from the factory. It is necessary to keep the heat out of the transmission at stock power levels. It is twice as important at twice the stock power levels because you are theoretically putting twice as much heat in the exhaust. Protect your fuel tank bottom and your rear diff from the exhaust heat as well. I boiled the fuel in the tank without a shield. Pickup trucks and big SUVs in the junkyard will often have metal shielding that will fit over a 3" exhaust pipe.

I also use that stuff on my car. Along with cleaning with brake cleaner I also got some 3m spray glue and spray up before I put in the foam stuff. It has helped hold it all up. But yes that stuff made a huge difference in temps in the trans tunnel.

Thanks for the input shuiend! I figured I might as well do something about it if I'm going to be down there and taking everything off!

This is the stuff. I wish I'd known about it when I did my Miata clutch. I learned about it afterward. when I did my C5 clutch, and stuck some to the inside of the tunnel plate.

Was going to get the stuff six recommended for when the clutch is installed in the next week or so. Couldn't find the frost king stuff in any of my searches. Turns out it's entered by a different name now.

Here's a link to it at home depot: E/O 12 in. x 15 ft. Self-Stick Foam/Foil Duct Insulation-FV516 - The Home Depot

The ThermoTec 2000F Heat Barrier adhesive back sheets are really sticky and meant for this. But it still can lose it's grab if the tunnel is not rediculously clean and smooth. Good luck. I found adding some rivets with flat washers in critical areas stopped the poorly adhered areas to stay inplace and not unstick any further. Maybe something like that would be good for that home dipshit crap some of you guys are "playing with fire" with ;]

That is the correct stuff. Just make sure to buy some 3M adhesive spray when at home depot racing and use that in the trans tunnel before you put in the insulation.

The other option that Savington now swears by is this product. I have purchased it, but yet to get it installed in my car to see how well it works.

How much of that ish d
id you need? It's on amazon prime so I could have that here without changing out of my PJ's. Sounds like a win to me, esp if it's rated for a higher temp.

I'm trying to shield both passenger and driver footwell areas from heat. Last summer my GF and I were melting from the heat kicking up from the tunnel area. I only have a 2.5 inch exhaust, but I'll find something else to put around that (seen pat mention a bunch of stuff) so that there's less heat radiating to the trans.

You want this:
https://cimg1.ibsrv.net/gimg/www.mia...5f4b179dee.jpg

https://www.miataturbo.net/race-prep...shields-90059/

Genuine MAZDA 3 Heat Insulator BP4K-56-441F | eBay

I didn't use any additional adhesive and it is still there. I used chlorinated brake cleaner to degrease the area prior to installation and that was all it took.

I'd love that stuff except, I really don't want to drill more holes into my car. I already had to do it for the roll bar and to fix the rear sway bar struts. Any more is just inviting rust...

Ah okay, just realized that your stuff comes with a TON more of it too compared to the thermotec. If it works/worked well enough for you on track... I'm sure it's never going to give me trouble on a street car.

Thats how I did mine originally and had a few pieces fall off. The 3m adhesive spray was less then $10 and easy to do. So it may not be needed in all cases, but surely does not hurt at all.

I did DEI on the Red Car several years ago (build thread link: https://www.miataturbo.net/build-thr...6/). Still there and doing its job well. For any of these stick-on solutions, degreasing is key. I can't remember what I used, but brake cleaner would certainly do the trick.