Where to insulate?

[lippy]

Another insulation question. My ERA is coming in about 2 months (hopefully). I was planning on using Dynamat or something like it on the entire interior and inside the trunk. But when I spoke with Doug at ERA, he said to just do the underside of the tunnel and nothing else. In his opinion, it doesn't do a ton of good and the insulation makes the carpet installation difficult, and the carpet may not stick as well. Any opinions would be appreciated on: (1) how much good the insulation actually does, and (2) if it causes problems with the carpet.

The other option I thought of is to install the insulation per Doug's recommendation under the tunnel, and use some of the 3M sound deadeners on the doors, floor, and trunk panel. Thanks!

[patrickt]

Originally Posted by lippy

I was planning on using Dynamat or something like it on the entire interior and inside the trunk. But when I spoke with Doug at ERA, he said to just do the underside of the tunnel and nothing else. In his opinion, it doesn't do a ton of good and the insulation makes the carpet installation difficult, and the carpet may not stick as well. Any opinions would be appreciated on: (1) how much good the insulation actually does, and (2) if it causes problems with the carpet.

1) Do not insulate the inside of the trunk; 2) Do not insulate the inside of the car; 3) Insulate the front and sides of the foot wells, as seen in the pic of my car below -- this is really the only place you really need to insulate; 4) The underside of the tunnel is purely optional -- I don't think it makes a difference, I don't have mine insulated, and it doesn't get hot on the inside of the tunnel. I've been under there when everything else on the car was red hot, and that area was still not hot.

[DanEC]

I'm sure I've gone overboard but I used a thin (.040) mastic sound deadning mat over the entire interior and Cool Mat on the floors and tunnel, inside of footwells and inside firewall. Also Lizard Skin on the underside. But, I have underfloor exhaust. I used the mastic to deaden any noise and vibration from the aluminum panels. I plan to do the floor of the trunk with the .040 mat just to make sure that "big" flat trunk panel stays quiet. Without side exhaust or solid lifters I won't have as much engine noise to mask vibration and panel noise.

Just from test starting my car and running it at idle for about 5 minutes last week I noticed the floors were already pretty warm and that is after ceramic coated exhaust, Lizard Skin, B-Quiet mat and Cool Mat on top.

With side exhaust you probably wouldn't need (or want) as much as I put in. I'm probably going to be hauling about 50 lbs of sound deadner and insulation around but I'm not building the car to have the fastest, baddest boy racer around.

[lippy]

Originally Posted by patrickt

3) Insulate the front and sides of the foot wells, as seen in the pic of my car below -- this is really the only place you really need to insulate

Is insulating on the outside only adequate for the footwells, or does it still get warm inside and possibly require insulation inside as well? Btw I'm using sidepipes, not undercar.

[DonC]

Don't overlook the optional wheel well vents and engine compartment exhaust heat shields. Both help get the heat out of the car before it gets to you. I second the use of insulating the foot boxes particularly. They can get pretty toasty being as close to the exhaust as they are.
I have side exhausts on my roadster so I don't have the floor heat issue that you do but, except for the hottest weather, my interior stays pretty close to ambient outside temp just with the above.
DonC

[patrickt]

Originally Posted by lippy

Is insulating on the outside only adequate for the footwells, or does it still get warm inside and possibly require insulation I side as well?

I do not believe you need to put any insulation on the inside of the car. I don't believe you need to put any insulation on the tunnel, either inside or outside -- the tunnel is easy enough to pull if you want to do it later, for some reason, but I don't think you ever will. And I really don't believe you need anything, ever at all, other than carpeting, in your trunk area. Don is right about the extra venting and heat shields -- I have that and it does, indeed, make a difference.

[lippy]

I am getting the extra venting and shields. So what I'm starting to think is that I'll insulate the tunnel per Doug's recommendation. Can't hurt. And I may use some of the 3m sound deadening panels on the floors, doors, trunk, and rear bulkhead. They are about $11 each, small, and apparently effective.

[patrickt]

Originally Posted by lippy

I am getting the extra venting and shields. So what I'm starting to think is that I'll insulate the tunnel per Doug's recommendation. Can't hurt. And I may use some of the 3m sound deadening panels on the floors, doors, trunk, and rear bulkhead. They are about $11 each, small, and apparently effective.

OK, just remember that everything takes forever to do on these cars, even things that shouldn't. So, if it's a relatively easy place to get to (like your floor) I'd leave it off until you get your car up and running. You then might decide you don't need it, or you can then put it on your list of "to do" after you get the real stuff done -- and you will have plenty of real stuff. Puhhhlleenttyyy. I'm serious, though. It's something about these cars, but even the simplest, half hour job can easily spill in to an all-day thing.

[DanEC]

Unfortunately Patrick has a point - why else would I be 3 years this month into my ERA build and still looking at probably 6 more months to complete. Oh-well, it was a retirement project (before I went back to work).

At a minimum insulate the inside of the transmission tunnel. Old factory Corvettes had tunnel insulation because of the heat from those aluminum body Muncie transmissions. A cast iron Toploader (if that's what you are using) will warm up to be a big chunk of hot steel and heat from it will radiate right through that aluminum tunnel metal. Anything else just depends on your objectives for the car and what you feel comfortable with.

[patrickt]

Originally Posted by DanEC

Unfortunately Patrick has a point - why else would I be 3 years this month into my ERA build and still looking at probably 6 more months to complete...

... that's why I just threw money at the elves in New Britain and my car magically appeared just the way I wanted it.

[Dimis]

Originally Posted by patrickt

It's something about these cars, but even the simplest, half hour job can easily spill in to an all-day thing.

Haha too true!
Well for me at least.
I'll "just" polish it - I thought to myself.
80hrs in and I've only managed the door and hood scoop and the front quarter panel

[Donunder]

Not another insulation idea but an additional approach to keeping the footwells cool -well, less warm- is to run pipes from the brake duct openings. These are for the most part just screened with some perforated alloy sheeting for the sake of appearance or left alone altogether. Why not put them to use?
I have PVC pipes running from just behind those openings up through the inner guard on each side and then mounting onto the top of the footboxes directing fresh air down to both footwells. It's a straightforward installation, no switches flaps valves etc etc and the difference is noticeable. No rain gets in. I guess if the weather turns really cold you could always just pop some sort of bung into the mouth of the pipes but that sort of weather is foreign to me. Use in connection with relevant insulation of course.

[patrickt]

Originally Posted by Donunder

Not another insulation idea but an additional approach to keeping the footwells cool -well, less warm- is to run pipes from the brake duct openings.

Yeah, those come standard on the ERA cars. Air scoop inside nose But they also have an optional in-line blower seen here: Installing fresh air fans which I don't have, and have always wondered if they really did anything or not. Here's a pic for those of you who are too lazy to click the links.

[kevins2]

Hey Don and Patrick,

Both of you mentioned heat shields. I got the wheel well vents but missed the heat shields. I just found them in the manual but the drawings don't really show much and I can't picture what they look like installed. I haven't installed an engine yet, so I assume the heat shields would be pretty easy to add? I can contact ERA, but thought I'd ask you guys since you both have them.

Regards,

Kevin

[patrickt]

Originally Posted by kevins2

Both of you mentioned heat shields. I got the wheel well vents but missed the heat shields. I just found them in the manual but the drawings don't really show much and I can't picture what they look like installed. I haven't installed an engine yet, so I assume the heat shields would be pretty easy to add? I can contact ERA, but thought I'd ask you guys since you both have them.

Think of the shields as "upside down L-figures." They're made of aluminum, are custom fit, and each side is different. You can see the shot of my passenger side, through the wheel opening, with the wheel well vent and battery removed. The other pic is of the driver side, with the wheel well vent still there -- so look through the mesh and you can see the heat shield over the pipes. Installation is a pretty easy, straight-forward job... meaning it will take most of the weekend.

[kevins2]

Thanks Patrick, I'll call ERA and order a set. Interesting that the manual states the passenger side shield is only used when the battery is moved to the rear. Apparently, that only applies to newer cars or you found a way around that. I have the trunk-mounted battery so not an issue. By the way, you seem to have photos of every square inch of your car from multiple angles...

Regards,

Kevin

[patrickt]

Originally Posted by kevins2

By the way, you seem to have photos of every square inch of your car from multiple angles...

I take her apart, and then put her back together again, just for fun... and play like I'm a real mechanic.