sound/heat isolation with panelling

[spatz]

Another question................
Several builders have been putting insulation or damping material between the aluminium panels.
Factory is not recommending it and I can only guess that water that enters in there can become a nasty thing
with foam inside the panels. However there is foam that is not taking any water and I wonder if there is anybody
that has a first hand experience with this and can comment on the pro and contras:

MANY THANKS !

[738 driver]

If you can get the foam sheets in the exact correct thickness that would be okay. I would not used expanding type cavity foam though as this may cause distortion of the ally double skins.....Some sections of double-skin panelling are unsupported for a fair distance as regularly the chassis cross braces beneath them are of a smaller section than the main sections. (main chassis tubes might be 38mm and cross braces 19mm etc which creates sectional voids).
Due to possible ingress, condensation,spacing etc I eventually went with a double sided silver bubble material as used in the building industry. Comes in 15mm thick, 400mm wide rolls, very lightweight, insulates, heat resistant etc... can be cut/doubled as many times as is required to fill the section. Similar stuff is sold at B&Q, less than 20Euro per 5mtr roll.
Recently done the panelling so the info is quite current.
There are so-called purpose made materials but I thought they were quite expensive by comparison.

[DHGTR]

Have you compared an insulated and non insulated car, in my opinion sound proofing is just pointless, i now wonder why i bothered to fit a radio at all.

Dave

[spatz]

yes that comparison would really interest me

thanks

[738 driver]

My thoughts were split, 50/50 heat and/or sound insulation.

[DHGTR]

DHGTR said:

Have you compared an insulated and non insulated car, in my opinion sound proofing is just pointless, i now wonder why i bothered to fit a radio at all.

Dave

It wasnt a complaint by the way, the engine just sounds so sweet.
Ok on a bit of a jaunt it might get to you but there are always earplugs.

Dave

[Gulf -LS2]

DHGTR said:

Have you compared an insulated and non insulated car, in my opinion sound proofing is just pointless, i now wonder why i bothered to fit a radio at all.

Dave

i totally agree.....

part of the enjoyment of Ultima ownership for me is the noise, smells and shear speed. If you want to sound deaden buy a R8 or something, i think Ultima ownership will be a disappointment for a lot of people!!

[738 driver]

Gulf -LS2 said:

DHGTR said:

Have you compared an insulated and non insulated car, in my opinion sound proofing is just pointless, i now wonder why i bothered to fit a radio at all.

Dave

i totally agree.....

part of the enjoyment of Ultima ownership for me is the noise, smells and shear speed. If you want to sound deaden buy a R8 or something, i think Ultima ownership will be a disappointment for a lot of people!!

Na......... that cant be right Kyle.. you are jumping ship to those nice, quiet, economical LS motors soon!
And whats this about using an R8 for sound deadening.....we'll all get locked up if we start chopping up R8's to stuff inside our panels!

[LuckyP]

IMHO, lightweight insulating of the natural drums that double skin ali paneling creates absorbs the horrible high frequency tips and taps that you get from stones and creaks etc, but leaves all the lovely low tones that you get from the V8. If you don't do it you'll never know!!

PS. I have a lot of off-cuts of Noise Killer product that I will give FOC to the first collector.

Pete

[Pilot Pete]

I used the same stuff Stig used, quite expensive, but very easy to cut to get a perfect fit, then you just peel and stick.

[spatz]

what about the Dynamat, I can get it for a reasonable price from the german distributor which happens to be a long friend and
I thought about applying it from the inside from both panels. That should get rid of all the high frequency rattling ?
What about the engine bay facing part of the panels, I can imagine they pick up heat from the engine
and then maybe the Dynamat is falling off (glue getting hot?)

thanks

Edited by spatz on Thursday 26th March 08:15

[UltimaCH]

Hi Spatz,

Saw this for rear bulkhead insulation. I believe some Ultima owners have also adopted this type sheet.

http://www.crracing.com/racing_performance/gold_re...

[Graham-P]

You really need to heat protect the side panels where the radiator pipes are close to the cockpit (ask Tuxman how he burnt his leg one hot summer), I have also wrapped the radiator pipes, some say don't, but I've had no engine temp problems. If you are going to connect the heater up try to run the heater hoses under or around the luggage containers and lag them, not through the containers, as you can get conductive heat from them, Vintage Air do a electronic heater valve, so you can position that anywhere along the hose.
The places you should concentrate on are the rear of the luggage containers these need to sealed off from the engine bay also each side of the chassis top rails under the dash (not sure that makes sense!) It's the triangle shapes at the front, top of the chassis. If you look down into these you can see the radiator pipes.
What happens, especially in a CanAm with the roof off, is when you go over a 'few leptons' the low pressure area over the top of the cockpit starts to draw air from cockpit and if you haven't done any heat deflection or sealed the engine bay from the rest of the car you can feel the hot air being drawn from under the dash, spewing very warm sometimes hot and uncomfortable air over your feet then your face, compromising the air con etc.. . . . where does this air come from. . . the engine bay. . . . then it travels under and around the luggage containers. . . . . over the radiator pipes. . . .and up through the top chassis rails into the cockpit. . . .(ask me how I know!!!) You will find that the luggage container lids will 'pop' open over 80 leptons or so as well. . .
Also think about a cold air feed from the brake duct into the cockpit either direct onto the blower motor or just into the front of the cockpit onto your feet.
Take a look at Stig's CanAm site, the panel under the battery and master cylinders fills with water on very wet driving and putting slats into this panel, as he did, is a must to stop it filling to the top of the chassis rail, you'll find that if you do this it will also help to decrease the pebbles that accumulate there as well.


Graham

[spatz]

Dear Graham,

very helpful information, pipes will be insualted and I will also try different runs
and apply heat shielding cloth wherever heat is generated including luggage containers.
I wonder if you can actually have a few holes in that panel underneath the luggage containers
or even apply a vent that has its opening directing to the back of the car, so spray water cannot enter
but collected water can find a way out ?

Also I have seen that the factory LS7 Ultima has aluminium panels underneath the gearbox and engine.
I would love the idea to have a complete covered bottom, both helping keep engine bay clean and maybe
even generate more ground effect ?

thanks

[60mph]

Hard foam is good for heat insulation but poor for sound insulation ; it's so light it just moves with the sound waves and passes them on . It is used by some loud speaker manufactuerers as part of the cone ! I think for sound deadening you need something very open weave , fibreglass wool , or something very dense . Aston Martin used to use a 25mm thick layer of sponge with a layer of 1mm thick lead half way through . I'm not suggesting using this on Ultima because it was for use inside a saloon car where there was little heat , but the density of the lead is a good idea .

Frank

[spatz]

yep I have been checking on different sound insulation material, there is a cheaper alternative to Dynamat
called Alubutyl, and of course the regular heavy tar mat self adhesie. If you apply this all then the car will sustantially gain weight like at least 10kg more.
Btw did anybody apply stone chip protection on the bottom alu panels ? There is quite sticky heavy stuff as well, maybe just enough.

thanks

[Steve_D]

I stonechip painted all of the underside on mine.

Steve

[andygtt]

DHGTR said:

Have you compared an insulated and non insulated car, in my opinion sound proofing is just pointless, i now wonder why i bothered to fit a radio at all.

Dave

I had a radio in my canam and could hear it fine.... I put a similar material to dynomatt on my alloy panels and it hugelly reduced the road noise... I also put a sound deadening fibre matt in the bulkhead and lined the side pannels with a heat retardent fibreglass/silver film the same as whats fitted to the underside of the rear clip.

If water can get between the alloy panel then it is almost certainly getting into the chasis rails which are exposed steel inside.

I highly recomend sound deadening.. and it only added 5-10kgs to the weight of my car.