spare tire?

[bryanf89]

i want to get a donut style spare tire for my 89 supra to replace the stock heavy one. i found a tire for a 2003 and up corolla that has the 5 bolt pattern. will this work, if not, what will?

[cre]

What are the dimensions and offset and what is the load limit? You'll need to make sure it'll clear both the front and rear brakes.

[Busted Knuckles]

Unless it is a 16" rim, it will not clear the front calipers. I tried to put some donuts on a parts car for it's last trip to the salvage yard, and a 16" donut with minimual offset managed to fit. A 15" or smaller didn't clear the brake caliper. I managed to fit that one 15" on the rear, tho.

BTW, I hate those donuts. They will limit your car by speed and agility, and it flat out sucks to have to drive 50 mph on the interstate with trucks blowing by at 70. Trust me, it only happened once with me, and I'll never do it again. Every car I bought after that with a donut got a full sized spare immediately.

[cre]

Sometime 16"s don't even fit (they hit the outer face of the caliper)... If possible it would be best to try to arrange a time to test fit them.

[bryanf89]

thanks i had found one but it didnt fit in the space where the previous spare had been lol

[MA70-3.0GT]

To be honest, the only reason you could have for wanting a donut spare is for weight saving right? I certainly hope you ain't going on looks!

Anyway, for the amount of weight you'll save over a full sized alloy wheel & the limitations (some would say danger) caused by the narrow tyre style, I'd say you'd be much better off just carrying 2 or 3 cans of tyre foam (it's called tyreweld here in the UK, think it's fix-a-flat in the US?) and/or a footpump.

At the end of the day, unless you're really unlucky you're not going to have more than say 1 or 2 flats every couple of years & most times just pumping them up will get you to a garage. It's up to you really, but I'd say either stick with a "proper" spare or if weight's that much of an issue don't have one at all.

EDIT-: if you wanted I suppose you could offset the weight of a proper spare by running only enough fuel in the tank for the journey you're doing, after all if you're concerned about a few lbs you're more likely doing short runs round a track or strip rather than the daily commute I'd guess...

[bryanf89]

Yea your right i wont sacrifice safety for only a lil bit. Ill focus on power first and weight as my second priority

i seem a carbon fiber hatch if i get that along with a CF hood wud the weight distrubition be right? Would it be too light?

[cre]

The only CF hatch I've ever seen was a custom, one-off piece that a guy paid a lot for. if you've got that kind of cash then worry more about building the engine for more power and less about losing the weight. Reducing weight from the MKIII is not an easy feat. the hood and hatch weight a lot less (relatively) than you may think.... the hatch glass (which you'll still have in a CF hatch) is the heavy part of that piece and you'll loose more weight than you would from swapping the hood by simply replacing the drive shaft with a lightweight, one piece DS.... AND it's a reduction in rotating mass AND it's central. Lighter rims; again even weight reduction AND it's rotating mass.

Oh, and if your car is a targa top... trade it in for a hard top... they're lighter too.

As for the spare... get a AAA membership and ditch it except for when you're going on long trips. Hell, the last time I needed to use a spare it was dry rotted to hell and had no air from lack of use. I do still carry one, but only becuase I don't have anywhere to store it outside of the car.

[bryanf89]

yes but where do i find a one piece lighter drive shaft? im proud to say that mines is a hard top,frankly, i think ill just modified whats under the hood and deal with the rotating mass as well. the car really is a true classic in Japanese muscle car history. anytime i drive theres at least 5 people tell me how they amaze to see it in original mint condition.

im planning on getting 18in rims with low profile tires...as for whats under the hood i want to rebuild and modified the 7m engine get a bigger turbo, electric fan, lighter pulleys, lighter and bigger intercooler as well as the radiator, as well as replace some the stock tubing with some aluminum ones merly for engine dress up. as for suspension i seen some tokico shocks that work nicely with TEMS and some eibach pro kit lowering springs. i will get a complete exhaust system straight pipe no cat(its illegal but i got my hook ups

any recommendations?

[cre]

Originally Posted by bryanf89

yes but where do i find a one piece lighter drive shaft?

Have one built at a GOOD drive shaft shop? Just a thought.... There are a few places that sell them online, they're also made to order as you have to measure for a precise fit.

I had these guys build me one: http://www.jawsgear.com/ It's superbly balanced!

I'm not fond of 18's on MKIIIs with lowered suspension... too rough of a ride on Colorado roads for my tastes. They do look good though.

Electric fans aren't much of an upgrade (if any). They add just as much resistance to the alternator as the stocker does to the water pump.... If you want to lighten the load get a flexible aluminum fan (and of course the proper fan clutch, a stock fan clutch would spin it so fast the new fan would explode). The flex fans flatten out the faster they spin and thus there's less resistance, that combined with the fan clutch at highway speeds you're barely using any power to keep it moving and it's really just the oncoming air that's cooling the rad.

Performance aluminum radiators aren't any lighter in the end... a lot of the time they weigh more due to the extra coolant capacity. The extra coolant capacity and additional area for heat transfer is the reason you run one, no weight. An aluminum OEM replacement would be a weight reducer, but there's no other benefit.