Firewall insulation solutions ?

[David]

I've searched the forum and I can't seem to find the answer.

Finishing up round two of the restoration and I want to add sound and heat insulation to the firewall while the motor is out. Spoke with Carl Nelson who said that Dynamat will slip down over time. Has anyone successfully used something that works well and lasts ?

I know the stock part is available, but I'm hoping a better solution is out there.

TIA

-David

 

[David]

I've searched the forum and I can't seem to find the answer.

Finishing up round two of the restoration and I want to add sound and heat insulation to the firewall while the motor is out. Spoke with Carl Nelson who said that Dynamat will slip down over time. Has anyone successfully used something that works well and lasts ?

I know the stock part is available, but I'm hoping a better solution is out there.

TIA

-David

 

[corsachili]

I've had a combination of Dynamat Extreme and Dynamat hoodliner on the firewall of my CSL for over 4 years and it has not moved an inch. As long as your firewall is completely clean I don't think you'll have any problems. I was just removing some Dynamat Extreme from my transmission hump last night and I'm here to tell you that the stuff sticks like herpes. It's fierce!

-tj in Los Gatos

PS-wear Mechanix gloves when you install it, the edges are SHARP and will cut your fingers.

 

[corsachili]

I've had a combination of Dynamat Extreme and Dynamat hoodliner on the firewall of my CSL for over 4 years and it has not moved an inch. As long as your firewall is completely clean I don't think you'll have any problems. I was just removing some Dynamat Extreme from my transmission hump last night and I'm here to tell you that the stuff sticks like herpes. It's fierce!

-tj in Los Gatos

PS-wear Mechanix gloves when you install it, the edges are SHARP and will cut your fingers.

 

[MichaelP]

Generally, whether it's a house or a car, you want to put insulation on the side of a wall where the source of heat or noise is. Given that, you have a few options: (1) just go with the stock arrangement, being sure that firewall holes are well-plugged with rubber grommets, (2) use the stock firewall panel with panel liner inside. I did this to an S14'd 2002 (serious heat/noise) and it was relatively effective. It never slipped, at any rate. A third belt-and-suspenders option might be to lay the asphalt panel liner on the outside of the firewall with the stock panel over that. I haven't tried it, and there might be some fitment issues due to change in corner radii at the transmission tunnel. The foil surface of the asphalt liner may not like things sticking to it or putting weight on it either, but it might be worth looking into.

 

[MichaelP]

Generally, whether it's a house or a car, you want to put insulation on the side of a wall where the source of heat or noise is. Given that, you have a few options: (1) just go with the stock arrangement, being sure that firewall holes are well-plugged with rubber grommets, (2) use the stock firewall panel with panel liner inside. I did this to an S14'd 2002 (serious heat/noise) and it was relatively effective. It never slipped, at any rate. A third belt-and-suspenders option might be to lay the asphalt panel liner on the outside of the firewall with the stock panel over that. I haven't tried it, and there might be some fitment issues due to change in corner radii at the transmission tunnel. The foil surface of the asphalt liner may not like things sticking to it or putting weight on it either, but it might be worth looking into.

 

[David]

I spoke with Dynamat. They suggested placing the insulation on the cabin side. I think I'll get the stock insulation part from Carl for the engine compartment, and then pull the carpet up for a layer of Dynamat Extreme and Dynamat hoodliner on the inside. I can see this getting expensive.

Thanks for the help.

-David

 

[David]

I spoke with Dynamat. They suggested placing the insulation on the cabin side. I think I'll get the stock insulation part from Carl for the engine compartment, and then pull the carpet up for a layer of Dynamat Extreme and Dynamat hoodliner on the inside. I can see this getting expensive.

Thanks for the help.

-David

 

[MichaelP]

That sounds like the simplest way to go about it. The inside/outside route does a good job of mediating heat transfer. I was less impressed with noise suppression. Before you get into it, put some thought into how the carpet and pads are to be held in place. The foil backing on the liner is really slick. If your carpet is currently kept in place by friction, that won't work after the liner is in place. I used strategically placed doublestick velcro squares.

 

[ElRey]

Floor & tunnel shield

Here's what I'm going to use. I'll let you know how it works out.
Regards,
Kingman

Part number
DEI 050503
DEI's revolutionary Floor and Tunnel Shield material adds a new dimension to control heat with a minimal clearance of only 3/16" needed. Constructed by utilizing an embossed 10 mil aluminum face bonded to a 1/8” composite fiberglass insulation and backed with an aggressive adhesive that holds past 450º F. This material is capable of handling direct temperatures up to 1750° F. Tough enough for under vehicle applications. Floor and Tunnel Shield can also block out up to 50% of unwanted road noise.

 

[ElRey]

Floor & tunnel shield

Here's what I'm going to use. I'll let you know how it works out.
Regards,
Kingman

Part number
DEI 050503
DEI's revolutionary Floor and Tunnel Shield material adds a new dimension to control heat with a minimal clearance of only 3/16" needed. Constructed by utilizing an embossed 10 mil aluminum face bonded to a 1/8” composite fiberglass insulation and backed with an aggressive adhesive that holds past 450º F. This material is capable of handling direct temperatures up to 1750° F. Tough enough for under vehicle applications. Floor and Tunnel Shield can also block out up to 50% of unwanted road noise.

 

[David]

Is that going on the engine side of the firewall ? Ill bet that will look nice. Any concerns about keeping it clean ?

-D

 

[David]

Is that going on the engine side of the firewall ? Ill bet that will look nice. Any concerns about keeping it clean ?

-D

 

[Stefan]

I had my car running when restoring with only inside isulation installed. I noticed when driving the car that the heating was worst at passangers left foot. The tar was even melted!

I think if you would take care of heating problem, a heat barrier of metal is the best. Any kind of expensive material is and will be inferior. Air is and will be the best isolation material ever inventet by.......someone!

 

[Stefan]

I had my car running when restoring with only inside isulation installed. I noticed when driving the car that the heating was worst at passangers left foot. The tar was even melted!

I think if you would take care of heating problem, a heat barrier of metal is the best. Any kind of expensive material is and will be inferior. Air is and will be the best isolation material ever inventet by.......someone!

 

[gwittman]

Air is and will be the best isolation material ever inventet by.......someone!

Vacuum is better.

Talking about heat, does the coolant flow to the heater core actually get shut off when the heater is turned off. I know with some vehicles the air flow through the heater core is blocked when the heat is turned off but the heater core itself is still hot because hot coolant still flows through it.

 

[gwittman]

Air is and will be the best isolation material ever inventet by.......someone!

Vacuum is better.

Talking about heat, does the coolant flow to the heater core actually get shut off when the heater is turned off. I know with some vehicles the air flow through the heater core is blocked when the heat is turned off but the heater core itself is still hot because hot coolant still flows through it.

 

[jhjacobs]

I know my heater core runs all the time; I don't know if its broken or what. I thought is was an auxiliary radiator to keep the engine cool in the summer time. :? I put in a new firewall to hood seal and it made a huge difference in the summer cabin temperature. I've also picked up a used solenoid-driven Mercedes A/B diverter valve that I plan to install one day to allow me to electronically bypass the heater core.

 

[jhjacobs]

I know my heater core runs all the time; I don't know if its broken or what. I thought is was an auxiliary radiator to keep the engine cool in the summer time. :? I put in a new firewall to hood seal and it made a huge difference in the summer cabin temperature. I've also picked up a used solenoid-driven Mercedes A/B diverter valve that I plan to install one day to allow me to electronically bypass the heater core.

 

[cpeavey]

Water constantly circulates through the heater core. The defrost and footwell heat is controlled by flaps, or dampers, in the heater box. "Instant heat." If the flaps seal properly, the system works great. If you have an owner's manual with your car, it contains a pretty good diagram of how the system works.

Charlie P.