Cliff Notes: Looking for advice on Heat Shield design/location/mounting for a Road Racer/Hill Climber.

So I had an earlier thread about fuel... thanks so much for the help!

I got the car out last weekend for the Pagoda Hill Climb (in Reading PA). Had an absolute blast!

However, I'm 99% sure there is no heat shielding between the exhaust and other various parts of the car, starting from the header and going backwards. I'm pretty sure someone took them all off to save weight. However, it not only becomes unbearably hot in the car, but the trans tunnel will literally cook anything that touches it after a 100 sec run up a steep hill (including my gloves, oops). I need to divert that heat away from the trans tunnel (and most likely the trans, fuel cell, etc). I haven't gotten under there to see exactly what the situation is, yet, but I'm damn sure it's not great.

So my question for the group is.... would I be better trying to pound out some aluminum and putting it directly in the tunnel and mounted to the chassis (stock style), or could i potentially build "umbrellas" and clamp them to the exhaust at various points from the front to the back? My main goal is to prevent heat build up in the car, on the chassis, and on the drive components. My secondary goal is ease of install and access to other parts, as my car is in a pretty awful location for this kind of work (middle of nowhere, no driveway/asphalt/etc... kind of like a field). I might just pull it up on the trailer (dove tail with open center) to do the work... but either way... it needs to be done. If poop hits the fan at a race, I may need to be able to access the trans or fuel cell quickly.

Followups:
Is it better if there is a buffer between chassis and aluminum, so that the heat doesn't transfer easily?
If I were to do the "umbrella" route, are there any considerations on the materials used to clamp to the exhaust? Should there be a buffer between the shield and the pipe?

Thanks in advance!

 

i'm not sure what is easier, but if you had a stock shield, maybe start there?
if not there are threaded tabs on the floor pan

you could also wrap the exhaust, there are some downsides, but some times it is better

 

I could probably start with the sock shield in the tranny tunnel, but it is an aftermarket single exhaust, so it takes a different route than the stock Y pipe. I really need to get under there to take a look. Another issue is, i'm not ready to cannibalize my other FCs.. yet =). haha

I'll do some research on the wraps. I figured the heat would eventually get through a wrap and I'd be right back at square one after 10-15min on track. In the information I did find on this site, it sounds like this rots the system faster?

 

the wrap would rot the system faster, but sometimes its still better to wrap the exhaust. maybe not the whole thing, but sections, or even a part

 

DEI Floor and Tunnel shield on the under side of the transmission tunnel. Some pics for reference:
https://www.rx8club.com/rx-8-racing-...2/#post4996569

If you do wind up finding or making aluminum heat shields, yes, you do want an air gap with those. I'd honestly just do the DEI. The stuff works amazingly well. I'm still tempted to wrap the exhaust on the RX8 but going to wait until I've had some more time on track to determine if I need anymore heat control there. I might just wrap it near the diff to try and keep the diff cooler.

 

I am a big fan of a proper ceramic coated exhaust, but its expensive.

Had mine done at Zircotech in the UK

 

I'm not looking forward to cleaning the tunnel, but I'm totally digging this. Looks like it would be a lot easier than bending/rolling aluminum for the length of the car....


@GeenIdee Does this require a speical application or can I use the Ceramic Exhaust Paint that's available in a rattle/spray can?

 

No, something that you "paint on" will barely do anything, if anything at all.

This stuff from zircotech is plasma spray ceramic. They got colors but the performance white that I got is good for 1400C / 2550F with +/-33% surface temperature reduction.

They use it for everything I believe, like composites near exhaust systems for instance. You can do your intake if you want

 

POR15 makes an excellent degreaser that I used when I did this on my cars. Spray it on, scrub with a nylon kitchen/bath brush, hose off. Dirty but easy job.

 

The factory heat shields generally do not fit with aftermarket exhausts, so they have to be removed. Sucks.

Could be worse, it could be right hand drive! I have heard of people's shoes melting to the floor during a race.

 

Ha.. yea that would definitely suck.

For sure if i was sitting on that side, my *** would have been on the cooker and my belts, shoes, etc would have been smoking. Seems like a serious safety hazard.

I'm going to do the DEI stuff on the tunnel, but I think I'm stil going to need to put a shield on the transmission. My brake bias lever is also there and probably needs protection too.

 

The NA and NB Miata have the header right at the driver's feet. Your feet get real toasty during a race! DEI at the firewall in front of the driver's feet made a huge difference. Along with the trans tunnel.

 

It almost happened to Keichi Tsuchiya. There's one video of him driving an FD on circuit and the floor camera showed him tucking his clutch foot back because the firewall got super heated.

 

I used adhesive backed DEI Heat Shield material on the bottom of my race car on the passenger side of the car above the exhaust. I used foil tape on the edges to help seal it against rain. The hardest part was cleaning the bottom of the car. Where I couldn't get the hear shield to stick I used pop rivets and fender washers to hold it in place.

I have been using this stuff for close to 20 years. Never had it come off. Since the photo below was taken I have switched to a 100% stainless exhaust system which also helps to deal with heat. I also put heat shield material on the right side axle tube, around the right side brake lines and on the right hand side of the fuel cell. .