Adding Lightness to my 911 (the easy way)

[Woodyhfd]

My '87 Porsche 911 coupe came with the inflatable/collapsible spare tire. In addition to combining a heavy wheel with a heavy tire, you also need to carry an air compressor in the car at all times. As far as I know, my spare has never been inflated in the past 25 years and, if it were to be, I'm not sure that it would hold air or fully collapse into its original shape when subsequently deflated. Because the spare wheel fits snugly into a recess in the 22 gallon fuel tank, there's not really any room for a full size tire.

During one of my daily Craigslist searches, I found a nearly perfect 14x5.5 inch Fuchs wheel that was originally fitted to a 912. In addition to its beautiful condition, it's really light. My original plan was to flip it for a quick profit, but then I started to think about using it in place of the heavy collapsible spare that came with my car.

I started by confirming that the wheel would clear the front brakes on the car.



I measured the collapsible spare and it was approximately 20 inches across, with a small gap between it and the fuel tank. I wouldn't have room for anything bigger. I thought back to the small 14 inch temporary spare tires in my old Miata track cars. I found that a Miata spare is 19.5 inches across, when inflated on its 4 inch wide rim. I quickly acquired one in exchange for a twelve pack of Smithwicks.



I had to go to three tire shops before I could get someone to mount the tire onto the Porsche wheel. The first two shop said that it couldn't be done. I had to work my way down to progressively less skilled technicians until I found one who didn't know any better. The third shop mounted it with a new valve stem for a total cost of $4.



The tire is really stretched, but he was able to seat the bead and it holds air without leaking.





I didn't want to use the original steel hold-down on the beautiful forged aluminum wheel, so I dug through my big pile of Fuchs center caps, picked out the crappy one, drilled a hole through the center and sent it for a trip through the sand blaster. I also picked up a slightly longer metric bolt, along with one composite and one neoprene washer. The result was a precision fitted hold-down for my new light weight spare.



The new spare fits perfectly into the recess in the fuel tank and I can easily check to see that it's holding pressure. The old steel wheel and collapsible spare weigh 34 pounds and the compressor added another 4.5 pounds. The new spare wheel and tire weigh 16 pounds, for a net savings of 22.5 pounds.

[wachuko]

How cool is that!!

[weseeeee]

Great idea, I can't say that my spare has ever been inflated. I'll check it this week end and be on the look out for a 14 inch Fuchs.

[Targalid]

Impressive insight on your part. Also it's purdy!

[911s55]

Great solution now all those 14" Fuchs will be wanted by more than the VW crowd.

[LJ851]

Very cool!

[wayner]

Apparently spare tires can be fun on performance cars

The Mercedes C63 AMG Experiment - CHRIS HARRIS ON CARS - YouTube

[plumb4u2]

Just curious...are you confident that if the time comes and you need to use the spare that it will be safe to drive on?

[Daves911L]

Nice idea!

Now, I don't know you, so I'll assume its not applicable in your case. But I never cease to be amused at the number of 270 lb guys who struggle out of the 8 lb buckets in their lightweight hot rods! Its generally cheaper to take it off you than the car! And the effect is the same

[Woodyhfd]

Originally Posted by plumb4u2

Just curious...are you confident that if the time comes and you need to use the spare that it will be safe to drive on?

I have more confidence in this tire than I did in the older, untested collapsible one. I wouldn't be using it for anything other than getting me home.

[RWebb]

Originally Posted by plumb4u2

Just curious...are you confident that if the time comes and you need to use the spare that it will be safe to drive on?

he said it was "really stretched" when inflated, so I'd expect trouble

[Reiver]

Want to add lightness, get rid of the 20 - 30 year old tire completely and get a new air comp fix flat that most GM cars coem with now...they don't carry spares anymore.

GM Tire Inflator Fits Many 2010 12 Vehicles Malibu Lacrosse Part 20846310 | eBay

[andybullen]

I don't know about you guys, but I would personally trust this over a 20+ year old tire that has never been inflated - a mild stretch like that should not affect it's driveability for purposes of getting home....

I could see these becoming the new thing to have!

[will hung]

This is clever. Many of the stance guys will be able to show that a tire stretched like that could be nursed home without too many problems. My concern is with the difference in overall diameter to the other wheels/tires. Have you fitted this to the car and see if it will set on 4 wheels?

[MattNZ]

The diameter of you new space saver inflated is the diameter of your collapsable spare uninflated. As will hung says, my concern would be ride height and ground clearance when fitted

[Amochosto]

Originally Posted by Daves911L

Nice idea!

Now, I don't know you, so I'll assume its not applicable in your case. But I never cease to be amused at the number of 270 lb guys who struggle out of the 8 lb buckets in their lightweight hot rods! Its generally cheaper to take it off you than the car! And the effect is the same

Lol, as a 6'4" 267lb guy.......

I agree with you, and I started a diet (more of a permanent lifestyle change really) last week. Hopefully my Carrera can loose 30 lb as a result.

[tobluforu]

Spare tire, what's that? Anyone want to buy my 14" fuchs?

[rothaus]

Originally Posted by Reiver

Want to add lightness, get rid of the 20 - 30 year old tire completely and get a new air comp fix flat that most GM cars coem with now...they don't carry spares anymore.

GM Tire Inflator Fits Many 2010 12 Vehicles Malibu Lacrosse Part 20846310 | eBay

This make sense, but the fuchs wheel looks so much better.

[KTL]

Couple of comments on the other comments

-A friend had a brainfart at a DE event a few years back and contacted another driver. Screwed up his front strut and gouged the heck out of his BBS wheel. We put our heads together and cobbled together something that he could limp home on. The solution was a wheel spacer (to get the wheel/tire to not contact the strut) and a collapsible spare. That Vrdestein spare worked like a champ. So don't be too quick to poo poo the collapsible spare. That sucker can work and is better than nothing!

Don't sweat the stretched fitment. Full on racecars often run a stretched fitment. It works fine.

The key is to make sure you put the spare on the proper wheel- ALWAYS on the front. So if you have a rear flat, take the rear off and the front off. Move the good front wheel to the back and run the spare on the front. This is especially important if you have a limited slip diff. The small spare on the back will make that side of the transaxle spin faster and wear out your LSD in short order!

[Reiver]

Originally Posted by rothaus

This make sense, but the fuchs wheel looks so much better.

Oh looks...thought we were talking light....btw, as I've been told every 100 lb delete equals abt 10 hp....cheap.