Trying to keep her cool.....  (my wife that is :-)).

These cars must the hottest bloody cars in the world to travel in when the temperature is over 30degrees C.  I've been pondering the issue for several years.  All the investigation I have done has found no decent heat insulations.  Proper sound deadeners are heavy, expensive and only hint they "may" slow heat soak....  Google will find several heat shield products they may work that actually have scientific testing proving their effectiveness....  however the price of even a tiny amount is simply eye watering.  Not a hope could I ever afford even a sample amount of it.

The car is a Citroen CX2500 GTi Turbo.  I've owned several of these since I was 16 years old.  The suffer horrific heat soak through the firewall and floors, to the point where you couldn't put your family in them in a hot day.

Then I found this:

http://www.lobucrod.com/

I must admit I was far from convinced.  Generally I avoid like the plague anything that constantly refers to "Customer Testimonials".... But it's cheap, it's cheap and it's very cheap... I could smother the car in the stuff given it's price.  And it's an "Insulator", not specifically sold as a "sound deadener".... As a bonus I won't add hundreds of kilograms to the car with it installed.

As my father bought this car into Australia from the UK (they were never sold here), it doesn't have air-conditioning.  Well I'm in the process of fitting air-conditioning (dual zone, front and rear evaporators).  So while it's gutted, lets add the insulation.  I ordered 200 square feet of the stuff.  It arrives in two separate rolls.





I was far from hopeful given the incredible lightweight of the insulation... It weighs the best side of nothing !



Yes I really did gut the car, no choice really when you want to get the heater box out to fit the evaporator.  The different colour red is where I found  rust in the floor and welded in some new floor sections.  I put the instrument binacle back in so I could bolt the steering wheel on and drive the car if required (yes, I'm definately insane, no doubt about it).  I also purchased a cheap SPL meter on fleabay and recorded how noisy the car was at 100km/h (dash in, driver seat and carpet in, the rest removed).



While the heater box was in bits to fit the evaporator I laid it all in insulation.  I also modified the heater box to dramatically improve the amount of air it moves (explained elsewhere).



I also used the insulation to seal up all the flaps inside the heater box, replacing the deteriorated old foam with it where I could.



Because I have heaps of insulation I put two layers on the front floor and firewall inside the car.  The bottom layer I glued down, the top layer is just taped over the top.  When I had half the floor insulated as shown, I decided to do some testing (I was dying to see if all this effort was a waste of time !!).



What I did was sit a temperature guage above the floor, both insulated and uninsulated sides, and blasted hot air under the car (just like what happens when sitting in traffic with the radiator fans screaming away at high speed).



I pointed the LPG/Propane fan forced heater at the floors (these things are bloody deadly with the heat they blast out).  Fingers crossed I wouldn't set the car on fire with it !!!!

Findings:

Passenger floor (no insulation)

Time in minutes	temperature just above floor level      Celcius             Fahrenheit	temperature of floor (metal)    Celcius            Fahrenheit	temperature of floor (factory body deadener)    Celcius                Fahrenheit
00	14                     57
05	18                     64.4
10	20                     68	60                    140	65                          149
15	26                     79	71                    160	73                          163.4
20	27                      80.6	73                    160.4	76                          169

Notes:

• After 10minutes there was a lot of heat coming out of the floor making it quite uncomfortable
• After 15minutes the body deadener was soft (this is why the cars wiring is embeded into the body deadener)
• Interestingly the sound/body deadener appears to transfer more heat, more quickly than the painted metal floor !!!  So much for thinking sound deadeners would slow the transfer of heat soak.
  
• Getting uncomfortably  hot in the car due to the heat radiating out of floor, I better let it cool down before I test insulated side.  The heat radiating from the floor is just like sitting in the car in traffic on a hot day.

Insulated side

Now insulation side. Note- 2 layers of insulation, bottom layer glued to floor, top layer taped over the top.

Time in minutes	temperature just above floor level      Celcius             Fahrenheit	temperature of floor (metal)    Celcius            Fahrenheit	temperature of floor (factory body deadener)    Celcius                Fahrenheit
00	16/17
05	17	20
10	16/17	23
15	17	24
20	17	26

WTF ? Lets check... Yep damn heater hasn't fallen off and is still pointed at the floors.

Is the bloody heater really working, it's roaring like it always does ...




can even feel the hot air coming out at the back of the car ... hmmm

Time in minutes	temperature just above floor level      Celcius             Fahrenheit	temperature of floor (metal)    Celcius            Fahrenheit
25	18	27
30	18	29
35	18	28

THIS IS FANTASTIC !!!!  I think it will really work....  Direct comparisons like this, though not scientific simply can't lie !!!!  Damn I'm impressed.

UPDATE:  At easter we towed a loaded ( 6' x 4' ) enclosed trailer on holidays in 30+degree temperature...  car loaded to the gills, family onboard, trailer so full it took two of use to close the doors on it (eek).   It is the ONLY comfortable trip we have done in the car, and not near bloody died of heat exhaustion.  Even after crawling through the adelaide mountains (low speed, high power 25-45km/h corners) for 1hour, then idling stationary in heavy traffic for 20minutes.  The front floors were still cold to touch (previously we would have been dying due to the heat coming out of the floors).  An interesting point to note:

The rear floors ....  These only have ONE layers of insulation (not two like the front), these were warm to the touch.  This suggests 2layers of of insulation is perfect, and more than adequate, but for severe heat soak, 1layer will still transfer some heat.


I really did use the insulation everywhere...  It's amazing the uses you find for it, once you have heaps of offcuts of it around.



Gaskets for the heater ducting (that is sealed up so poorly from the factory it's laughable).

The boot air-con unit.... The plastic housing doesn't seal....  It's also a joke, it would suck mostly exhaust and petrol fume contaminated air from the boot.

Pictures of where insulation was fitted:



I put "gaskets" of insulation behind the door trims.  These are clamped into place, not glued so I can still access inside the doors.





The firewall and the back of the bonnet done.  You can see where I've covered the whole heaterbox and made gaskets for all it's joins with the insulation.



The parcel shelf... The speakers no longer fitted with the rear-air-con unit underneath.  So I made the wooden boxes you see, these were covered in insulation too, then covered with the headliner fabric.



I covered the roof while I had the headliner shell out to fit a new headliner.



The boot... Note the insulation gaskets added to rear air-con unit.


SOUND

BEFORE INSULATION
At 100km/h with the SPL meter sitting on some
cloth where the passenger seat is .... The meter hovers around mostly 2 calibration, with the meter on the 80dB setting.

AFTER:
At 100km/h, meter hovers around -2 at 100km/h.  I know bugger all about sound meters, what does "-2" on the 80dB settings signify, and what does "+2" on the 80dB levels signify ???  Dunno, but the car is a hell of a lot quieter, and no longer stinky (even with oil dripping directly onto the exhaust).  I haven't sealed up the wiring harness hole in the firewall yet either.... Or checked the gasket between the bonnet and inlet tower !!  The improvement is very pronounced. 

This is the meter I used.  I have no idea what the differences mean in a real life situation.  Given how much quieter the car was, I expected a much bigger measured difference.

OK, update, I've been told on forum, due to the way the human ear works, a 5dB increase is doubling of the volume.  Now we have a 4dB decrease in volume, so the insulation has staggeringly nearly HALVED the volume of the car at 100km/h.