Space saver spare Options

[Montreal914]

In the quest of increasing the space in my front trunk to integrate an oil cooler, I came across this piece of information that I thought was worth sharing.

Mercedes has been using Vredestein Space Master 165-15 collapsible spares on their smaller models like the C230 and the SLK.

After looking at the pictures and comparing them to my 911 space saver on steel wheel, I think they are the exact same tires.

The difference is that it is mounted on a 4.5" alloy wheel, not 5.5" like the Porsche.

So, one though to gain trunk space would be to mount the space saver tire on a ~$100 4.5" Fachs from cip1. Lighter and narrower wheel, win win. The goal would still to have it laying flat for impact absorption, yet probably allowing a lower trunk floor and giving room for the front mounted cooler to vent out.

Now the challenge is finding a place that will want to remove the collapsible Space Master tire and mount it on the Fachs... (IMG:style_emoticons/default/dry.gif)

Below is the MBZ space saver wheel/tire.

[Montreal914]

Right! And i believe some later 911 also have alloy 15x5.5 with collapsible but not sure. Looking at the 4.5" Fachs, the offset makes the wheel center protrude a fair amount outward going against my goal of thinning the wheel... (IMG:style_emoticons/default/dry.gif)

So my current 3 options are:

1- 986/996 spare: 3.5",light, full diameter, inflated.
Below is a mockup with a Mesa style cooler with a fan on top. The trunk floor is lower that the stock one. (IMG:style_emoticons/default/smile.gif) To achieve that, I would need to cut a ~9x9" opening in the floor though... (IMG:style_emoticons/default/sad.gif) Inlet would be front plugs.






2- 911 or alloy collapsible: 5.5", heavier than 986/996, small diameter, requires compressor. (IMG:style_emoticons/default/dry.gif)
Below is the mockup using a Mercedes Diesel oil cooler, the narrower one, which fits under the arched shelf. This doesn't require any body cutting, just remove front 5 plugs and 2 rear access ports.
As for area, 5 ports = 11.1 sq.in., and 2 outlet opening = 25.1 sq.in., so Ratio is good! (IMG:style_emoticons/default/smile.gif)
The trunk floor is pretty much at the same position as the stock setup or even a little lower or without angle.




3- Fachs 4.5" with temporary donut (125/70-15): 4.5" anrrower than 5.5" (but center protruding), light, OD 22", inflated.
Unfortunately, I don't have the wheel setup to validate this option but I think either cooler configuration could be used but there probably wouldn't be any gain in trunk space vs. option2.

So, at the moment for more of a "bolt on" setup, I am leaning towards the collapsible option but I definetly need to either find an alloy collapsible spare, or find someone that can swap the tire, which as mentioned earlier, can be very difficult... (IMG:style_emoticons/default/headbang.gif)

All of these options will require a custom trunk floor that would seal all around to create a plenum. Air path would be pretty turbulent compared to the beautiful work below but that would be my first step.

@Mark Henry :
This is McMark's setup! (IMG:style_emoticons/default/pray.gif)



And this is the integration done in PMB's recent build (IMG:style_emoticons/default/pray.gif)

[drem914]

Beautiful setup