Sound and Heat Insulation Question

[skovensky]

We are getting close to installing our Engine and I was wondering what people have used for heat and sound insulation? Do you put Dynamats inside the interior compartment - behind the sits, footwells, etc.... and do you also put them under the hood and around the engine compartment?

Thanks so much for the help?

Stuart Kovensky

[2bking]

If you are using Dynamat, it would be placed on the inside under the carpet and under the footbox tops. Some put the Dynamat on the inside of the firewall. I think the only heat insulating material on the outside would be a reflecting type metal heat shield. It would be spaced off the footbox sheet metal with an air gap under it where header pipes are close to the footbox. There is no need of insulation of any kind under the hood or else where. But wires and other sensitive items may need to be shielded from the heat radiated from the exhaust.

[carlewms]

If I had an air compressor that would have handled the job, I would have used the spray on type product like LizardSkin. I chose Dynamat Extreme for the cockpit instead. Best applied when it's warmer in the garage, it sure is thin enough and cuts with an exacto type knife or shears.

[skullandbones]

Hi Stuart,

Here's one way to do it. I wanted a little more sound damping so I used some thin green underlayment used for hardwood surfaces and then a layer of conventional carpet padding on top of that which was actually the third layer with the "Hushmat" under both. It's Summits version of Dynamat. I've used both and they are very similar and very sticky. I found that there were some very close areas where the extra thickness made it more difficult to get some things to fit but with some creativity, it will work. There is a lot of dead space in the cockpit so there are only a few real critical areas that have to be addressed like the emergency brake. I also did the "Hushmat" under the trunk alum, firewall inside, and any other space that was likely to get heat or noise. Hope that helps. Some pics to make it more clear.

Note: There are many different strategies but the important thing to achieve is getting dissimilar materials (even air) between you and the noise or heat but especially noise. Mine has worked well so far. The only place where it could be better would be in the front of the foot boxes. So at some point, I may add some aluminum heat shields just in those areas with a 3/8 inch space of air.

Good luck,

WEK.

[edwardb]

Some type of insulation should be applied to the entire inside cockpit area, with specific attention to the footbox areas. I happen to also like applying it to the back of the firewall, although not everyone will agree it's necessary. I also like applying it to the trunk area because I think it gives an overall solidness to the chassis, but again that's just my opinion with no data or proof that it really does what I think it does. I've used spray-on Lizard Skin for both of my builds, and like it very much. Just about any of the other spray or stick-on products should also do the job. Then apply the carpet over the insulation. The main points for footbox heat management are insulation and some type of ventilation. With those two things, heat should be managed.

One variable you haven't mentioned is what engine you're using. The amount of clearance and air space in the engine compartment, specifically to the footboxes by the headers, depends on your engine, headers, cats if used, etc. IMO, if there is adequate airspace, I don't think engine compartment heat shields or whatever are really doing much. With small blocks and BBK headers, for example, there is reasonable airspace to the footboxes. I've never noticed much radiated heat to the footboxes requiring any additional insulation. There's a lot of moving air in there.

[NukeMMC]

I used FatMat on the cockpit and trunk interior for sound deadening. I used the aluminum-faced fibreglass, adhesive insulation in the engine bay on the footnotes and on the firewall.

[skovensky]

This is really helpful, especially the pictures. Thanks so much

[walt mckenna]

I used 1/4" foam insulation with foil both sides on the engine side of firewall & foot boxes and all of the cockpit including the foot boxes. I attached the insulation (and carpeting) with two sided duct tape to make it easy to replace down the road. Noise from the engine and drivetrain is nil and heat transfer into the cockpit is not detectable.

[skovensky]

Just want to thank you all for the help on this. We had a few month delay in our build with distractions from school for kids, etc......We went with the Second Skin kit for the Roadster and placed on firewall prior to engine install and will do the rest of the cockpit, footboxes and trunk soon.