Corvette Forum : DigitalCorvettes.com Corvette Forums banner

1 - 14 of 14 Posts

·
Registered
Joined
·
879 Posts
Discussion Starter #1
Like so many of us, my C3 is really hot inside. I decided to take out the seats and carpet and install some reflectix insulation. This is what was under the carpet, some old Reflectix, sort of half ast installed.



OMG! BUBBA WAS HERE!
Do you think this might be the source of some of that heat?


The shift boot is too small to cover this massive hole.


I cut some coil stock and fabricated a patch. Not much better than what Bubba did, but it should keep out the elements.



Now the shift boot has something to be attached to.



I tried to keep a solid sheet of reflectix in as many areas as possible. A 6 foot long piece is enough to cover from the firewall to behind the seats, all you have to do is tuck and cut along the way to fit it in nicely. Foil tape keeps the seams neat and tight. Reflectix is available at Lowe's, this insulation project cost under $50.00.

 

·
Registered
Joined
·
4,607 Posts
Thanks for the writeup. Now all you need is a road test! Get out and bring us some positive data.
 

·
Registered
Joined
·
879 Posts
Discussion Starter #3
:agree:

I am waiting for the big brown truck to bring some new parts this week. I need to get the new carburetor installed before I do any more driving. I also have a new alumiinum radiator on the way and a rebuilt steering box from GTR1999 should arrive later this week.
 

·
Registered
Joined
·
3,808 Posts
I did the same thing for my '75. Started at the firewall, and went all the way to the back ! Also, pulled the door panels and put it there too.
 

·
Registered
Joined
·
422 Posts
Looks great. Does it make a noticeable difference for the amount of effort. I have quit driving mine until summer is over due to the heat. I will be interested in hearing the results.
 

·
Registered
Joined
·
636 Posts
A bit off topic, but I'm curious what transmission you're running. The shifter bracket (and console plate) looks identical to mine (I'm running a Doug Nash 5 spd), and I'm bolting the shifter to the rear position. Everything bolted in without cutting (although it is stinking tight). Just curious (from a technical standpoint) about the difference between your packaging issues and what I have.
Let us know your impressions of the insulation changes after you've had the opportunity to put some miles on the car. It certainly ought to be a noticeable noise and heat improvement over the stock stuff.
 

·
Registered
Joined
·
697 Posts
I see you have a '79. So do I. I redid mine as well two winters ago. Re-sealing the passenger side air vent door and making sure your hood weather strip is good also goes a long way in blocking un-wanted hear from getting it.

Re-plug any dash firewall holes you can find too!
 

·
Registered
Joined
·
1,196 Posts
I did the same thing for my '75. Started at the firewall, and went all the way to the back ! Also, pulled the door panels and put it there too.
I also did the same thing but really wasn't happy with the results. I really didn't notice a big difference. The first time I used felt and the stock carpet. The second time I used super dyna mat for the 1st layer and then another layer from Lowel's. It was no better then the felt.
I also did a double layer inside the doors and Tee roofs
 

·
Registered
Joined
·
879 Posts
Discussion Starter #9
A bit off topic, but I'm curious what transmission you're running. The shifter bracket (and console plate) looks identical to mine (I'm running a Doug Nash 5 spd), and I'm bolting the shifter to the rear position. Everything bolted in without cutting (although it is stinking tight). Just curious (from a technical standpoint) about the difference between your packaging issues and what I have.
Let us know your impressions of the insulation changes after you've had the opportunity to put some miles on the car. It certainly ought to be a noticeable noise and heat improvement over the stock stuff.
It's a Richmond 5 Speed (same thing). I did not do the original transmission installation, I bought the car that way, so I can't tell you much about the modifications, other than the humongous hole in the trans tunnel.

I am sure that sealing up the hole in the trans tunnel will be a major improvement. There was a whole lot of hot air coming in from there. The new Holley carburetor is being installed today, so I will hopefully have some feedback for you tomorrow.
Tonight - ROAD TEST!
 

·
Registered
Joined
·
517 Posts
I've taken a slightly different approach: I insulated the outside of the cabin. While the drivetrain was out, I put selfsticking R3 foil-back duct insulation on the outside bottom of the car from the firewall footwells back to the gas tank.
I also put a layer of it on the footwell splashguards.
In conjunction with the OEM trans tunnel blanket, I made a trans tunnel 'horseshoe' from a rolled up 24" X 24" piece of foil-back 1/2" fiberglas insulation stripped from a house A/C coil box. I also used other pieces of the same under the floor mats inside.
My idea is to keep the heat away from the mass of the body rather than reduce the radiation once it is in the body.
I only have a few days and a couple hundred miles on it, but with temps in the mid 90s and sitting in an open parking lot all day, it does seem to have helped some. We will have to see if this idea is a good one or not in the long run, but I'm trying it. Someday when I get into the interior, I'll do all that
.
Wrapping my headers also made a big big difference, I'd like to wrap more of the exhaust in the future.

Another trick I did was to open up my sealed off rear "Astro-Vent" doors behind the seats so my rear vents actually work. I cobbled up a flapper door from plastic cut from a gun case, made duct tape hinges and velcro latches. This was just to see if it worked, and it does, very nicely. This winter I will fab an official door for it. The airflow through the cabin when this door is open is great--there is a breeze when the windows are up, and noticably reduced wind buffeting in the cabin when the windows are down.

Later, John
 

·
Registered
Joined
·
879 Posts
Discussion Starter #11
I've taken a slightly different approach: I insulated the outside of the cabin. While the drivetrain was out, I put selfsticking R3 foil-back duct insulation on the outside bottom of the car from the firewall footwells back to the gas tank.
I also put a layer of it on the footwell splashguards.
In conjunction with the OEM trans tunnel blanket, I made a trans tunnel 'horseshoe' from a rolled up 24" X 24" piece of foil-back 1/2" fiberglas insulation stripped from a house A/C coil box. I also used other pieces of the same under the floor mats inside.
My idea is to keep the heat away from the mass of the body rather than reduce the radiation once it is in the body.
I only have a few days and a couple hundred miles on it, but with temps in the mid 90s and sitting in an open parking lot all day, it does seem to have helped some. We will have to see if this idea is a good one or not in the long run, but I'm trying it. Someday when I get into the interior, I'll do all that
.
Wrapping my headers also made a big big difference, I'd like to wrap more of the exhaust in the future.

Another trick I did was to open up my sealed off rear "Astro-Vent" doors behind the seats so my rear vents actually work. I cobbled up a flapper door from plastic cut from a gun case, made duct tape hinges and velcro latches. This was just to see if it worked, and it does, very nicely. This winter I will fab an official door for it. The airflow through the cabin when this door is open is great--there is a breeze when the windows are up, and noticably reduced wind buffeting in the cabin when the windows are down.

Later, John

Hey John,

Sounds like some good ideas that you have there. I also treid making a trans tunnel seal out of some pipe insulation. I tucked it in between the transmission and the tunnel just behind the bell housing.

Do you have any pictures of your "Astro Doors" that you modified? I might like to try that approach as well.

Thanks!

Lee
 

·
Registered
Joined
·
517 Posts
DV8,
I don't think the vents will work for you--that's for the flat window coupes with the louvers behind the window. Non-A/C cars had an atmospheric vacuum operated flapper to let them open for venting, but A/C cars just had them blocked off with fixed plates screwed on.
 

·
Registered
Joined
·
636 Posts
Like so many of us, my C3 is really hot inside. I decided to take out the seats and carpet and install some reflectix insulation. This is what was under the carpet, some old Reflectix, sort of half ast installed..........................................................................

.....................................................................................

While waiting for parts (new third gear set) for my transmission repair I got bored and decided to replace the anchor-like shifter bracket that I had been using. I've still got some massaging to do on it, but it's a boatload lighter than the steel bracket.


 
1 - 14 of 14 Posts
Top