NO SPARE for 2024??

[briang0901]

Originally Posted by gkubed

Do you know if the Styrofoam placeholder out of the '24 models fits well on the first gens? The OEM spare doesn't fit over my brakes, so no sense in lugging it around. It would be nice to have an OEM solution to filling that gap though.

Do you still have your spare?

[bababooey]

planned on salvaging my spare from gen 1 when I move to gen 2. no timeline on that tho. pickins are still slim

[Luns]

Originally Posted by ruturaj001

Regular spare
Spare Foam Spacer: 52153PA181

My 2017 '86 has no foam spacer under the tire. Toyota's owners manuals seem to bear this out; the later versions that cover TRD edition, they show the foam spacer only for cars that have a 17" spare wheel, while 16" spares do not have it. I haven't checked Subaru's equivalents, but expect they would be the same.

The parts diagrams I see for this part number seem to indicate it's a sheet metal 'volcano' that's spot-welded into the bottom of the spare tire well to provide the nut the retain bolt threads into. Presumably they wanted this nut higher to allow a shorter bolt for more accurate positioning. It's shown on the same figure as other sheet metal components forming the trunk compartment.

The need for the spacer isn't so much for the respective tires being 16" and 17", but rather that the 17" rim for Brembo brakes is domed out much more to clear the brakes. So with the tire (rubber) resting on the trunk floor, the centre of the Brembo spare wheel would have to poke through the floor while the regular spare doesn't. The spacer is to bring everything up with the Brembo spare.

Odd observation: between the 16" and 17" spare wheels, the 16" is a closer match to stock 17" tires' effective diameter. The 17" spare wheel is the closer match to the stock 16" (JDM, Australian, China, maybe other makets) tires.

Additionally, the 17" spare from other Subaru models might not necessarily work. I'm thinking specifically of the spare for Brembo-equipped WRXes; some people assume since the WRX has Brembo calipers, the spare must work for BRZs with Brembos too. However, what they're missing is that the instructions for the WRX are to put the spare wheel on the rear, and install the fuse that puts the car into FWD mode. I imagine its the same story with other AWD Subarus.

So unless somebody has a way to put their BRZ into FWD mode, I wouldn't simply conclude some other Subaru wheel works. It might anyway, it might not, but you really need to test fit to know for certain, and not just deduce that it does.

[ruturaj001]

Originally Posted by Luns

My 2017 '86 has no foam spacer under the tire. Toyota's owners manuals seem to bear this out; the later versions that cover TRD edition, they show the foam spacer only for cars that have a 17" spare wheel, while 16" spares do not have it. I haven't checked Subaru's equivalents, but expect they would be the same.

The parts diagrams I see for this part number seem to indicate it's a sheet metal 'volcano' that's spot-welded into the bottom of the spare tire well to provide the nut the retain bolt threads into. Presumably they wanted this nut higher to allow a shorter bolt for more accurate positioning. It's shown on the same figure as other sheet metal components forming the trunk compartment.

The need for the spacer isn't so much for the respective tires being 16" and 17", but rather that the 17" rim for Brembo brakes is domed out much more to clear the brakes. So with the tire (rubber) resting on the trunk floor, the centre of the Brembo spare wheel would have to poke through the floor while the regular spare doesn't. The spacer is to bring everything up with the Brembo spare.

Odd observation: between the 16" and 17" spare wheels, the 16" is a closer match to stock 17" tires' effective diameter. The 17" spare wheel is the closer match to the stock 16" (JDM, Australian, China, maybe other makets) tires.

Additionally, the 17" spare from other Subaru models might not necessarily work. I'm thinking specifically of the spare for Brembo-equipped WRXes; some people assume since the WRX has Brembo calipers, the spare must work for BRZs with Brembos too. However, what they're missing is that the instructions for the WRX are to put the spare wheel on the rear, and install the fuse that puts the car into FWD mode. I imagine its the same story with other AWD Subarus.

So unless somebody has a way to put their BRZ into FWD mode, I wouldn't simply conclude some other Subaru wheel works. It might anyway, it might not, but you really need to test fit to know for certain, and not just deduce that it does.

Thanks, I was pretty sure I would get PP installed or upgrade to car with PP sometime down the line, I didn't put that much effort in to writing and researching 16" wheels.

[LRNAD90]

Originally Posted by ruturaj001

You never install spare in rear. If rear has puncture then you have to put spare in front and install front in rear.

Curious what the reasoning is behind your statement? Is this in the manual for the 86's? Is it about the difference in tire circumference and therefore difference in wheel speed left to right on the driven axle causing issues with the limited slip diff?

Not trying to be an A$$, but unless specified in the manual for some specific reason I think this is incorrect, and potentially dangerous advise from a driving dynamics standpoint.

Since the front tires handle much higher loads from braking, turning and usually carry the higher percentage of a vehicle's weight (since the engine is generally in the front), it is best NOT to install a temporary spare on the front.

I've always been under the impression if you get a flat on the front, that it is best to move a rear tire to the front, and install the temporary spare on the back.

As long as you are not trying to accelerate swiftly, or drive aggressively, with a temporary spare on the back of a RWD car, the small temporary spare is better suited to the loads the rear wheels will encounter.

And, although most seem to ignore it, it is best to remember that a temporary spare is only meant to get you off the highway and to a repair facility, not to drive around on for days (or more) till you repair or replace the damaged tire.

EDIT: Gen 2 cars don't come with spare tires, so there is no mention in the manual. Owners manual for Gen 1 cars does indicate to "Install the compact spare tire on a front wheel." as OP has noted. Have to assume this is because the temporary spare is of a smaller diameter, and the concern for wheel speed difference possibly damaging the limited slip diff.

When I'm wrong, I'll admit I'm wrong, but for those with other cars, know this is not a general rule of thumb for all vehicles, check your manual.

[nextcar]

Originally Posted by LRNAD90

When I'm wrong, I'll admit I'm wrong, but for those with other cars, know this is not a general rule of thumb for all vehicles, check your manual.

Good advice.

That said, it is a general rule of thumb for vehicles that have limited slip differentials to not run spacesaver wheels where the differential is. (Note that there are front wheel drive vehicles with limited slip transaxles, so sometimes you do not put them on the front...).

Any difference in circumference (larger or smaller) between the wheels connected to a limited slip differential has the potential to cause damage:

For clutch type differentials it will wear out the clutches.

For all types of limited slip it will generate additional heat and can lead to breakdown of the oil.

[Sapphireho]

Originally Posted by LRNAD90

EDIT: Owners manual for Gen 1 cars does indicate to "Install the compact spare tire on a front wheel." as OP has noted. Have to assume this is because the temporary spare is of a smaller diameter, and the concern for wheel speed difference possibly damaging the limited slip diff.

I've been told it can also make the traction and braking nannies freak out.