Macca

John - contrary to popular belief, although 18s ZZ21 are more expensive than 17s a set fitted at MegaTyres is $1860 for 235/265.

The difference is pretty negligible really. the 18s will help in turn in steering response but they do ride firmer. The 993 was designed or 18 in mind (993RS/993TT/993GT2/993C4S). The 964 however wasnt (964T was end of product life). A steering brace was availabe from the factory for the front axle and recommended for 18" fitment.

peterC2S

Pretty sure the later cars (92-) came out of the factory with 17"s. Quite probably for reasons of demand and aesthetics.

John McM

Herman's electrical heart has been refitted. 3 hours of which 1 hour was trying to get the fan shroud fitted on the rear of the alternator. A pr$&k of a job as the bolts disappear down the housing and it's a cramped working environment.

I will finish the belt tensioning tomorrow morning then take him out to annoy the neighbourhood.

Running out of things to do now. Just the radio to diagnose and the right hand side trim.

Luckily the next mod has just shipped from LA and should be here early next week so I won't be bored for long.

Macca

Indeed correct from 01 Sept 1991. Tear drop mirrors too, and also the head gaskets.

KiwiSean

I can only comment on 964s.

IIRC between 92 and 93 cup cars switched to 18" Speedlines. The RSR definitely ran a 18. If 17s were really faster then they would have run them on the those cars I'm sure.

Personally, I have 4 sets of 18s and 1 set of 17s. This is why:

I ran back to back tests with Hankook 214s on 17s and Hankook 221s on 18s. The 18s were slightly heavier rims but both light 3 piece wheels. The 214 is supposed to be a faster tire. Despite this I was personally slower on the 17s because I didn't like how they felt on track, the sidewall flex/ squirm didn't give me any confidence. I like a hard side wall that tells me everything. Steve was marginally faster on the 214 with a 17 than the 221 on an 18.

My advice to other 964 owners:

If you're mainly doing road use maybe take a 17 for comfort? Go for 18 if you want the look or can't get decent Cup 1s.

If you're doing track use, use what feels best. I'd argue none of us are consistent enough to notice the small impact of a rolling radius change.

I've got loads of 18s and anyone is more than welcome to try them out for looks or ride quality.

John McM

Interesting that these 18" http://www.trademe.co.nz/motors/car-...-692506655.htm are so much more expensive. $2,196. Phil got a relative bargain on the ones I sold him.

KiwiSean

Nice work mate, you're turning into a DYI master.

Makes me wish I could tinker with mine in the garage after work rather than sit in this apartment. Will have to settle myself with tinkering on the new race car for two weeks.

John McM

I know the feeling. I sat in Jakarta watching Discovery Turbo for 4 years. Seeing all these other mid life crisis types buying and modding interesting cars and I was surrounded by Toyota Kijangs and clogged roads. I often wondered whether I could ship a 911 engine over and rebuild it at my leisure. Now I just wander down to my garage and go for it.

Macca

Pete. Not sure on the 964 but the 1994 onwards cup cars including supercup and RSR all ran 18".

For the track I think a lightweight 18 is a good choice. Im keen to try the OZ HLTs out with track rubber but will probably use them as a road tyre (new Mich SS already fitted & laser balanced at CCS) until the 3 piece with Z221s on are shagged (Id be lucky if those make the end of the third track day on the SITT). After that the brakes get upgraded and the OZ can become the track wheels.........

You miss being on the tools with your I simply miss driving mine. Every free hour in NZ I want to drive...

John McM

Are you going to join the Langs Beach run on 9 March?

KiwiSean

hahaha, good idea. It's better the cars are away from me though, spend enough without them next to me. Would only get worse.

Oh yeah, that too!

Macca

I dint think of that. What is it? I was planning on asking Ron to organise a famous Sunday Drive to blow out the cobwebs. That said if you guys are going to run with a bit of pace Im interested. Doug knows the gig....

John McM

It's a run on the end of our pre SITT run to Cape Reinga. Think a longer version of bombing the motorway with those black stealth bombers flanked by a couple of white C4s and Doug leading the way in his Red C2.

ChrisB_NZ

I'm away until the 22nd. You are welcome to try them out when I get back to see if they would help.

kiwi 911

Yes - long story short - reducing the rolling diameter