Kavo

I have heard it motioned that the spare tire is part of the crash protection for a 911 and that it should not be removed for events such as driver’s education. Is this true? Does anyone have any further info on this topic?

Ed Kovalevich
Riesentöter Region PCA
Tech/Safety Chairman

Jeff Curtis

Actually, a Club Racer friend of mine and I were just discussing this the other day. Some Club Racers use the spare as a weight making device, meaning if they know they're not going to make weight, this is a quick way to add 31lbs.

...yes, 31lbs!!

To answer your question, things I have read, conversations that I've had seem to indicate that indeed the spare is useful in front-end crash protection for the 964 series...I would imagine the earlier 911s could benefit from it as well, with the spare tire holder being incorporated into the shape of the fuel tank.

Bill Gregory

[quote]<strong>I would imagine the earlier 911s could benefit from it as well, with the spare tire holder being incorporated into the shape of the fuel tank.</strong><hr></blockquote>
Perhaps except for the early 65-67's. The spare tire housing was redesigned in 1968 so the wheel could jump out of the recess without bursting the tank, in an accident.

Kavo

Bill,

does that mean, that in all cars after 1968, the spare tire will jump out of the recease in a front end collision? That would lead me to believe that you don’t need the spare in for crash protection.

Thanks For The Help!
Ed

Bill Gregory

Ed,

No, I believe that the tire serves a purpose in crash protection. That change says, at the extreme, if the crash is serious enough, the tire will let go without rupturing the fuel tank, which would obviously create a further problem.

I did some looking yesterday, and can't remember where I've read about the design/usage of the front spare as part of the passive crash safety. I know Joel Reiser (PCA Technical Committee) has referred to keeping the spare in for crash safety at DE's. Might be worth a note to Bruce Anderson (bruce1485@aol.com) or Allan Caldwell (allancaldwell@juno.com) to see if they can shed some light on your question, or point you to some documentation. I'd appreciate you letting us know what you find out.

Kevin

I think that we can approach this from a different point of view. I have seen quite a few 964's & 993's with off-road excursions, from the track or highway. Many times the damage was sustained below the front bumper aluminum rebar. The damage was also below the frame rails. The spare does absorb alot of energy. In lite of this it is a risk not to include the spare, the risk I feel is further damage to your a-arms and other suspension related items. Yes, in full out racing it is a risk you take and the bodyshop will love you more on Monday...

Speedraser

I remember reading that the tank was redesigned in about '68 to prevent the spare from damaging the tank -- maybe Paul Frere's "911 Story"?

A year or so ago, I saw a '96 993 C4S that had a high speed crash on the NY Thruway (I saw the car at a dealer). Apparently, it aquaplaned off the road at high speed and hit an embankment head-on. The nose was badly crushed, enough that the front wheels had been forced backwards into the rear of the front wheel wells -- a pretty major hit. The passenger compartment was completely undamaged, and both doors opened and closed - it was really quite impressive. The driver was unhurt, but for a few bruises.

The spare wheel remained in place and had folded up just about in half -- it clearly absorbed a bunch of energy. I leave my spare in while on the track.

KeithC2Turto

I do not know if it means anything but the new GT2 Turbos do not have a spair tire. This does not mean that it would not help in a frontal crash. It "might" mean that the car meets federal crash standards for the 996 with out it.

One could stuff a couple of bean bag chairs in the front trunk just in case! <img src="graemlins/roflmao.gif" border="0" alt="[hiha]" />

Keith
2000 ML
1991 C2 Turbo w Ruf mods
1972 911S R Grupe lt wt

Speedraser

996s and Boxsters mount their spares vertically, whereas the earlier cars mount them horizontally -- the 986/996 nose is a completely different design from all predecessors.