Sound Proofing

[60mph]

I have made and fitted a top quality carpet set for the Ultima . It's HD twist Wilton with nice stitched on edging . I've left lines of rivets exposed to keep the racy appearance . This is in order to cut down sound . I've also braced the rear bulkhead to the horizontal chassis tube holding the shoulder strap fixings . Total weight is 3.5 KG . There is now no echoeing round the interior . The sound is now very directional ; sraight through the rea bulkhead , unsurprisingly .

QUESTION ; Has anyone tried to sound deaden the rear bulkhead ? If so to what degree of success ?

Sound is now 25% down .

Frank

[V8Dom]

ive been thinking of carpet as well.. where did you get the carpet and how differcult was it to make?? im an engine man not interior!!!!!!!!!!!!!

dom

[Knotty]

I am just about to fit carpet. I want to carry the carpet up the sides
an also up the rear bulkhead.
Any info on suppliers and what type you used would be helpful.

Thanks. Tony.

[60mph]

The rear bulkhead carpet was fitted during my build and was supplied by the factory . I live close to Kidderminster where carpets are made . I bought a piece 4ft 6inches by 12ft . It is 9mm thick cost £55. Tel them on 01562 755769 and ask for a quote " Bell Twist Ebony , Stuck Roll , Slight Seconds ". The quality is much better than anything at Stonleigh .

Lay squares of thin / straight edge cardboard pieces on the floor and push them into the sides and corners of the floor . If you overlap them and then tape them together you will have a template for you carpet . I cut mine short of the rivet lines around the footwell and rear of the floor to leave the rivets exposed .

The sides are just measured with a tape and then cut . 2 pieces per vertical sides ; I cut mine so they met in the vertical bend in the sides . Also just below the rivet line .
Go along the same deciding which parts you want to cover . I even carpeted the ceiling !

When all pieces are cut to size the exposed edges will need edging which will have to be done by a trimmer . Edges which meet at a right angle in corners or elsewhere look better not edged .

Fitting is easy but good quality old fashioned contact adhesive is a must .

1 . Support the section of carpet temporarily and mark where the edge is with a pencil line or other .
2 . Remove that section and mask with masking tape the aluminium up to the pencil line where you don't want glue .
3 . Use a scotch pad and abrade the aluminium up to the tape to get a good key . Degrease the area .
4 . Spread glue on the aluminium overlapping the masking tape paying attention to the edges .
5 . Do same with carpet and place in position before too tacky so you can reposition if required . Peel of the tape .
6 . Firmly smooth into place and after a while when the glue has gone off use a hammer and tap all over to firmly adhere the carpet .

I took the seats out to carpet underneath them . If you do this use longer bolts in the seat runners and use a nut as a spacer to keep the runners off the carpet .

PM me if you would like a photo .

Frank

[Mjpmark]

Hi Frank,
My build is motoring now, so ill be in touch re your carpet, the job you did as i expected looks second to none. Your setting a very high standard here.
Speak soon mate.

[Knotty]

Frank.
Thanks for the info. PM sent.

Tony.

[V8Dom]

great info thanks...i had a look at my car this evening and as there is already carpet under the seats its only the floor area forward of the dropped floor i will need to cover.... great to know where they get their carpet, so it will now be a match
thanks again

dom

[60mph]

Dom

The carpet contact I quoted is different carpet to factory but matches quite well . I don't know what other Ultimas are fitted with .

Frank.

[Steve_D]

The carpet used can be quite thin particularly on the side panels and the bulkhead as there is little or no wear.
Carpet on the floor sees a little more wear but could be replaced with little effort.

Steve

[60mph]

Rightly or wrongly I've glued mine all over so it would be a nightmare to remove . Thats one of the reasons I used extra Heavy Duty carpet so it will last for years . I still have had no feedback on anyones' success or otherewise of sound proofing the rear bulkhead . I think anything inside the engine compartment would have to be fire resistant .

Frank

[Steve_D]

My build site shows how I skinned and insulated the whole of the roll cage. I did this during the build so have no reference as to how effective it has been. All I can say is that road and aerodynamic noise are predominant.

Steve

[Knotty]

I have done the same as Steve also.

[rdodger]

If sound proofing is what you are after, have you considered Dynamat?

[Steve_D]

All the ali panels on mine have Dynamat on them plus the skinning of the roll cage is also filled with horse hair matting.

If anyone else is going to skin the cage then be advised that I only bonded the skins on advice from the factory as drilling/riveting could weaken the cage.

Steve

[60mph]

Thank you everyone . I think I will fit a second bulkhead on the inside ; possibly plywood and then carpeted . Its a pity to cover up the factory carpet but it will still be insulating . I may fill the gap with something . There are some horses just over the road . Tempting !

Frank

[V8Dom]

my bulk head is carpeted direct onto the bulk head... I find it noisy inside but them my silencers are loud.....

If it was too quite it would feel like a lux car rather than raw car..

What advantages are you really going to get making another panel up covering the lovely roll cage....??

IMO not only will you loose room behind the seats but i really cant see it making that much difference in noise... the car is plastic and there is a massive V8 behind you...... I Bet sealing the doors/body , sealing the storage bins(amazing how much noise comes through those, and dynomatting the bulkhead and floor would give more benifit...... Anyway thats my opinion..

Dom

[60mph]

Thanks Dom

I'll try those other areas but also make a temporary inner bulkhead and if this makes a big difference make it permanent . It's tireing on a long journey and at 1800 RPM there is an unpleasant ressonance which someone else has refered to on their car .This is worse than the hand grenade effect when you accelerate , in terms of annoyance . I think it is intake ressonance which I had in a big way on my diesel land cruiser but mamaged to completely eliminate it by lagging all the turbo pipes , air cleaner assembly and main induction pipe . This approach is not possible with the ultima .

Frank

[738 driver]

Dont know which change system you have Frank but a surprising amount of vibration/noise is transmitted along the gearchange rods.......direct steel linkage from the trans/engine onto the side-panel/ luggage bin. It seems quite minor but is actually a sizeable contributor.

[Knotty]

All my panels - rear bulkhead, front bulkhead, floor, side panels have been
filled with acoustic foam which also has a heat reflective facing. The rear
bulkhead has 3 layers.
The cockpit is also going to be fully carpeted.
Not trying to kill the noise completely, but didn't want to get to the end of
the build wishing I had done something.

Tony.