[parptarf]

So when fixing my parking brake I decided to weigh my big and wide rear wheels. Some say they are too big and wide so they weigh too much. I thought I'd test this out.



OZ Racing Alleggerita 10x18" w/ Michelin Pilot Sport Cup 295/30 = 19.5kg

OEM 993 Cup (Cup II) 8x17 w StarComfort 235/45 = 21.5kg

Design90 8x16" w/ Goodyear studded winter tires 205/55 = 20kg



So this rear wheel with the wide tires on it are actually lighter than my small D90 winterwheels. It should be interesting seeing what these will weigh with 265/35 MS Pilot Sport 2 tires on them.

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[ds968]

Damn, for a second I thought the weights were in lbs and was vey impressed...only to notice ( after another sip of coffee ) that its in kg .

Ugh.

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[flash]

i've never seen the 993 Cup in an 8. what is the part number for that?

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[parptarf]

Might not be for a 993(Just what someone told me there are for), though they are original C up 2

I'll find the part number when I get home.

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[flash]

the name of the wheel is "993 Cup" for a reason. the wheel was designed for the 993. there are other widths and offsets for the 968, but i've not seen an 8 on anything yet. it would be cool though, as i would love to stick an 8 on the front of the white car.



if they are original though, i'm betting they are a 7.5" up front, and a 9" in the rear, which is what i have on the white car now.



let us know if you find it to be an 8. i'd love to get a pair.

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[banditsc]

There is a 17x8 rim, it's a winter wheel, but it's intended for the 911, it's offset is 70mm. 99336212601

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[flash]

lol - i'm getting old. i posted that part number a long time ago on the "wheels that came on our car" thread



looks like i need to go shopping

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[parptarf]

Sounds about right banditsc, the offset looks absolutely gross on the 968, even with a massive 15mm spacer on.

Not to mention the horrible tires they have on them. Glad I only used them for a brief week. <img src="/forum/images/smilies/968/biggrin.png" class="smilie" alt="" />



Though, a set of backup wheels is always nice to have.

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[flash]

if i find them, and i decide to go that route, i'll pin and weld a spacer on the rear, remove the material i can for weight, and then bore out the holes back to the correct thickness.

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[parptarf]

[quote name='flash' timestamp='1408981729' post='161555']

if i find them, and i decide to go that route, i'll pin and weld a spacer on the rear, remove the material i can for weight, and then bore out the holes back to the correct thickness.

[/quote]



I'd definitely do that. ET70 on an 8" wheel doesn't look too good.

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[flash]

lol - no. not even sure it would fit. wouldn't be hard to modify though. i'd probably push it out 20mm. maybe just longer studs would eliminate the need for the boring, and would be safer. i'll have to look at that. i'd definitely weld the spacer though, and remove a lot of material to lighten it up.



a lot of work for 1/2", but it's the ability to go 1 tire size wider up front without wallowing.

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[parptarf]

Should look good when it's done. What tire size would you use on the 8" wheel?

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[flash]

probably a 245-40, so 2 sizes up and a profile size down

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[parptarf]

I'm thinking about putting a wider tire on the front when I change the tires on my Alleggeritas.

I'm also gonna change out those 295 sections I have at the back, I don't really need that with.

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[flash]

yeah - i really wish porsche hadn't followed the 911 model when they set up our wheels. a 50/50 car should have the same size wheels all around, especially with the power level of our car. somewhere along the line designers got it in their head that wider was better. it increases frictional drag, wind resistance, and rotational mass, with little to no benefit to offset it.

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[parptarf]

So running, say a 8x18" with a 235/40 and 10x18" with 265/35 would be better than 225/40 and 295/30?

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[flash]

oh yeah. you'd lose a lot of understeer, and some rear rotational mass.

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[parptarf]

235/40 tire wouldn't have a too large diameter, right?

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[flash]

the O.D. is actually a bit small (24.5 vs 25" of stock)



8" rim is the minimum for that size tire.



make sure it's an 8" rim though, and not the stock 7.5"

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[Bulti]

"8" rim is the minimum for that size tire."



I got some info here from a tire webshop stating that even on an 7,5 a 235 would be ok. Not ideal, but ok.



For the 8" you can fit anything from 215 to 245.

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