[zcrow]

I want to put in a full-size spare on my SK. I can purchase the Wilderness under deck foam which will allow for a full-size spare or just remove the foam and use something else to support the floor.

The Wilderness foam is $140 in Canada + taxes. The alternate support (a piece of wood) is free. But I'm concerned that without the foam there will be road noise. For those of you who have gone with the alternate support method and removed the foam, have you noticed any increase in road noise?

 

[FozzieBalou]

Sure. Removing the foam insert will increase some noise, sure. It's a big metal well that vibrates. The wheel and the insert and the load floor and the carpet all absorb some of that vibration and (more importantly) noise. It's probably just a few decibels at most.

Will it be noticeable? Probably, depending on how easily offended by noise you may be. But then again, you can also turn up the radio to cover the noise ... Or you can add some of the noise suppression pads you can buy online (there are tons of posts on here about members installing this sound deadening materials)...

 

[zcrow]

I had considered adding in some sound deadening in that space. That would be about 1/2 the price of a new foam insert, and likely work even better than foam if I do everything.

 

[FozzieBalou]

Very true. But it also will add a bit more weight to the back of the car - as I think each sheet of that sound deadening material weighs between about 1/3 and 1/2 lb per square foot. With about 43 inches between the wheels and almost 36 inches deep, that means you're looking at about 11 square feet - but add a bit more for the depth of the sides of the well - which means you'll be adding another 6 or more pounds to weight .... not drastic...

The cost, however, will be a LOT more than the foam insert. In the US, the Dynamat brand will run over $180 US for 36 square feet - which is the smallest pack, I think. Other brands are cheaper for sure.

 

[vintage42]

... Removing the foam insert will increase some noise, sure. It's a big metal well that vibrates...

I removed the thick foam storage tray that covered the compact spare, and put in a full sized spare. I did not notice any change in noise. The heavy tire fills the well and dampens any vibrations.

The biggest reduction in road noise came from selling the OE Geolandar tires after a few thousand miles, and replacing them with Michelin Primacy (and when those wore out, Michelin Premier).

 

[zcrow]

That is good to know! Thanks. It seems that the SK is a bit different. When you take out the top tray you are basically opening it up to the bare metal under the spare. With yours, looks like there is still a fair bit of foam still left. I must say that I like your arrangement better. Nice to have a hinged access door like that.

 

[vintage42]

... When you take out the top tray you are basically opening it up to the bare metal under the spare. With yours, looks like there is still a fair bit of foam still left...

There is no foam in the well under the tire, whether the spare is compact or full size. How could any tire possibly rest on foam? Here is the foam tray in place, and the foam tray removed to show the compact spare. (The foam tray will not fit over the full size spare, and is replaced by a plastic storage bucket inside the wheel as shown in previous post.)

 

[zcrow]

I was just going by the one picture and couldn't see everything. Thanks for the additional photos. So yes, I can now see that it is similar to the way the SK is.

 

[CrystalPistol]

I would say that as long as you snug up the hold down wing bolt, the full size spare will do as much or more damping as the space saver and organizer, I'd like to find an extra rim and do same, plain steel would be A-OK.

But then I carry a bag with plug kit, good plugs, gloves, and a nice little 12 vdc inflator, so much easier than swapping out. I use only the brown gooey plugs for roadside repairs, and if the tire is good yet, I'll break it down later and pull in an umbrella metal tipped "plug-patch" for a more "permanent" repair.

 

[zcrow]

Yup. Have a ViaAir pump and tire repair kit with me all the time. I am going to be up in some remote places this summer where tire shops are very few and very far between so just want a full-sized spare for those "just in case" moments.

 

[FozzieBalou]

I keep all of that gear in an ammo container box that I can pop in or out of the back of the Foz for trips where I think it may be of need.

 

[notdavis]

I haven't replaced my donut with a full sized spare, but I have used killmatt purchased off amazon.ca and it made a difference

 

[zcrow]

Good job and good idea. I was eyeing that on Amazon as well. How much did you need to do the cargo area? I was looking at the different kit sizes and I'm sure which one will get the job done.

 

[notdavis]

@zcrow what you see is what I used, I bought one box, did rear and doors as far as I could reach without removing the vapour barrier, still have s lot left over - Ill check my amazon orders for specifics

 

[Natedog]

I removed the thick foam storage tray that covered the compact spare, and put in a full sized spare. I did not notice any change in noise. The heavy tire fills the well and dampens any vibrations.

The biggest reduction in road noise came from selling the OE Geolandar tires after a few thousand miles, and replacing them with Michelin Primacy (and when those wore out, Michelin Premier).

I just did the same in my 2012 and notice no road noise difference, bought spare 16" factory alloy used off ebay, mounted set of five General Grabber ATX 215/70r16 (about 1" taller than stock) and it fit barely. Need to buy longer wheel hold down bolt and weld a wing nut type peice on it.

 

[zcrow]

That is the same conclusion I came to as well. Cancelled my order for the sound deadening stuff. What I did end up doing is using some leftover 2 or 3mm rubber from a "barbque mat" and contact cementing it around the tire so that anything that I put in there won't be rattling around against the metal of the the spare tire wheel well.

 

[FozzieBalou]

I just did the back area on my 2014 Foz... I bought the "CANOPUS" branded butyl rubber stuff... it is an 18 sq ft kit - 9 sheets that are 15 * 19.5 inches per sheet.

2 sheets (each cut in half) were used on the doors, just at the speaker openings. The rest of the kit went into the rear cargo space. I do notice some difference, but then again it may just be a perception because of doing the job.

 

[CrystalPistol]

I keep all of that gear in an ammo container box that I can pop in or out of the back of the Foz for trips where I think it may be of need.

For like $11 or so, maybe cheeper, HF has some nice "tool bags" made of that tough nylon stuff, have pockets, and if bumped into or bump something, not near as rough on paint, elbows, or even toes.

 

[Oldguy2]

Looks like you decided on a solution already. FWIW, here is what I did last year to help reduce rear cargo area noise on my Forester that is a little bit different than the other suggestions. I simply laid a piece of mass load vinyl (MLV) under my accessory cargo tray on top of the cargo floor. MLV is a better sound blocker of road noise than butyl mat products (like KilMat) which only deadens the metal. I used some of that material too, but as you can see in the 3rd photo I only installed it in a few places around/under the spare tire, and not "wall to wall". My Subaru is quiet. Good luck

 

[OuchDamn]

I tossed in some dynamat and it's super quiet. Not the only place I put it though.