Cockpit road noise

[jancoombes]

Hi 1st post and all that..
I'm looking at ordering a kit after Christmas and I am gathering as much info as I can about the car 1st(GTR)
I've been reading some really, really good build sites.
Very helpful, thanks guys.

I'm planning to build "out the box" and I was going to skin the car in flat sheet carbon fibre.

I see there is an alloy double skin option, I take it this is to reduce engine noise?
Does it serve any other purpose?

Has anyone fitted any sound deading material to the car (brown bread etc)?

[steve_d]

jancoombes said:

Hi 1st post and all that.. I'm looking at ordering a kit after Christmas and I am gathering as much info as I can about the car 1st(GTR) I've been reading some really, really good build sites. Very helpful, thanks guys. I'm planning to build "out the box" and I was going to skin the car in flat sheet carbon fibre. I see there is an alloy double skin option, I take it this is to reduce engine noise? Does it serve any other purpose? Has anyone fitted any sound deading material to the car (brown bread etc)?

Welcome.
The double skin option only skins the lower part of the rear bulkhead i.e. from the top of the side pods down. I would regard this primarily as structural. The remainder of the bulkhead is about 3mm of glass fibre with carpet stuck on.
I have skinned and filled (sound matting felt) the roll cage on mine which I’m told is an improvement.
You should talk to Chris (stig) about the carbon skin as I’m not sure how you deal with the sheets that roll around the chassis tube.

Steve

[stig]

steve_d said:

You should talk to Chris (stig) about the carbon skin as I’m not sure how you deal with the sheets that roll around the chassis tube. Steve

In short, with flat-sheet carbon fibre, you can't napp them over the chassis rails. So you can either cut them all in ally, fit and napp them, then removeand use for layup templates for carbon fibre (not recommended), or use a carbon fibre sheet that is ally backed - mucho expensive (see Reverie website for details).

For sound deadening/insulation, lots of good products out there. I used a combi-insulation that provided sound, heat and fireproofing.

Also, the double skin kit not only skins the bulkhead, but the floor too.

>> Edited by stig on Thursday 3rd November 14:11

[mhussa]

I thought the factory don't recommend putting anything between the panels if you use the double skin kit? something about the 20mm air gap being adequate for noise/heat suppression. Does it make a difference adding the insulation?

[andygtt]

I fitted dynomat on the alloy pannels, makes a huge difference to the road noise in the cockpit although you'll never stop the engine noise so unless you coast it will still be loud. To be fair the main advantage of doing this is if you fit a stereo as it will make it hugelly more effective.

I also additionaly covered the side pannels in heat barrier to stop the rad pipes relaying heat into the cockpit.

[jancoombes]

Yep I thought it was the floor too, was planning to insulate between the skins and outside of the sides (so you can't see it)

Andy where did you mount your speakers, head unit etc, do you have a web site or any photos, you could email me.

Also has anyone fitted central locking?
I did not see it as an optional extra

[stig]

jancoombes said:

Yep I thought it was the floor too, was planning to insulate between the skins and outside of the sides (so you can't see it) Andy where did you mount your speakers, head unit etc, do you have a web site or any photos, you could email me. Also has anyone fitted central locking? I did not see it as an optional extra

'Factory spec' position is head unit in passenger footwell and speakers under dash and in rear bulkhead.

I have head unit in the dash (needs careful thought if you have aircon etc.) and speakers in footwells/dash and rear bulkhead.

I have a full 'install' on the Can-Am as well as central locking etc. Quite a few bits to consider with both. Have a look at www.ultima-canam.info for more details.

[andygtt]

stig said:

I have head unit in the dash (needs careful thought if you have aircon etc.) and speakers in footwells/dash and rear bulkhead. I have a full 'install' on the Can-Am as well as central locking etc. Quite a few bits to consider with both. Have a look at www.ultima-canam.info for more details.

I had my speakers in the footwell and with the dynomat the stereo was extremelly effective, I remember hearing a car with them under the dash and it's not the place to put them IMO.

We all know that Subwoofers require Wok's but again I don't think this is the way to go



>> Edited by andygtt on Sunday 6th November 10:09

[craig-ultima]

I have a double-skin GTR, and I put Dynomat on the rear of the cockpit, and an additional foam layer, and a layer of very dense rubber-backed carpet over all of that. None of this made any difference. The Ultima is a very serious racing car, and the engine is very loud in the cockpit.

What I have found very useful though is the use of "industrial application" ear plugs, like those used on the in-circuit at Nasrcar events.

[mhussa]

The knowledgable amongst the motorcyclist fraternity already know the value of ear plugs especially because of the risk of tinnitus:

www.tinnitus.org.uk/information/info%20sheets/front%20page/what_is_tinnitus.htm

Production car levels of refinement are what people are used to but the reality of a tuned V8 behind your brainbox re-adjusts your expectations. I'm going to try noise insulation regardless (can't hurt and isn't very heavy) but for those who are paranoid about the quality of their hearing in future years, the suggestion of ear plugs is the best so far.

>> Edited by mhussa on Sunday 6th November 13:13

[builder]

I like the idea of noise-canceling headphones and an intercom (as used in aircraft cockpit). The common ear-bud type can be used under a helmet on the track. Along with preserving what little hearing I have left, it makes communication much easier, too.

[jancoombes]

I've got a peltor system I currently use in my Westfield. but most of this is wind/gearbox noise.

The Foam that Stig is using on his Cam-am build looks good.
(Where did you get it from/what's it called)

I'm looking in to getting some noise cancelling head phones for shooting and they do some that looks like a hearing aid, I'll let you know what I find out.