V2Rocket

Doing some light wheel shopping and am thinking of getting 17x7 wheels all around so I can order 1 type/size of tire and rotate in the future...

But can't help but notice that the wheels I am looking at also come in a 6" width and would be a little bit lighter (both in wheel and tire weight) and we know lighter is better!

Skinny wheels and tires would make the car "light on its feet" methinks with the tradeoff in ultimate cornering grip (not something too critical in a street car).

I know the 924S has a 6" wheel option (phone dials I think) but anybody in a 944 doing it too?

snb13

I have a staggered summer set-up of 6.5" fronts (205's) and 8" rears (225's). The offset is somewhere around 30mm for the fronts, so I run them with a 7mm spacer. I've noticed nothing detrimental.

Van

My winter tires are 205s, which are a stretch on 7" wide phone dials. I had to seat the beads this way:

https://www.youtube.com/watch?v=abH9__WKMhc


Car feels good on that size!

924srr27l

In the Uk we call a Stretch scenario when the tyre width is narrower than the rim width EG fitting a 175mm tyre on a 8" (200mm) rim etc...


205 is a metric measurement for the tyre which is 8" and the wheel width is 7", so here the tyre is wider than the rim width.


So it's not stretched or should it need to be "blown" on with any assistance but will pump up easy.


I'm running 205's also on 7J x16 rims, this combo works well.


I wouldn't want to, or recommend using a 205 with a 6J width though, on my 924S they had 195 on a 6J which again had the wider tyre narrower rim scenario.


R

924srr27l

The difference in weight between a 6j & 7J is usually that much? A 6J rim will "Tip" and tuck in more when cornering, so I'd stick to a square 7" set all round.


For a low resistance set up you could fit 195mm tyres, but this is not a common size on 17", I think your best is 205/50/17.


17" tyres will probably also be heavier than 16's


R

Van

Maybe my winter tires were sitting around for a long time... but the beads were nearly touching each other, and I could figure out no other way to seat the bead. I can say that it doesn't look "stretched" on the rim - it looks just about right. But, since most people run 225s on the 7" rims, I figured the 205 would work on a 6" rim.

924srr27l

Ok, Winters sidewalls are a lot softer and in time they probably started bending inwards a bit like a Crossply Tyre, Some 911's have 6" Rim 205 wide Tyre, but they of course have no weight on the front axle. None of the production transaxles to my knowledge ? used a 6" and 205mm tyre, or a 225mm with a 7"?

I think many people when changing tyres Go for the "bigger" tyre thinking it's more grip! & better, but without opening a Large Can of Worms, I'll not ressurect the famous "Adverse effects of fitting bigger tyres etc...."

Porsche used a 225 tyre on the 951 but on the rear and with an 8J, they also used a rear 245mm tyre on a 9J, the 944 & 968 Optional 17" Cup wheels had 225 front Tyres but on a 7.5J and 255 rear on a 9J, but on a 968 I changed these to 7 & 8.5 and 205 & 235 width tyres which made the car accelerate faster, (lighter wheels & Tryes) also it changed direction quicker and the handling was an improvement.

You can overtyre a Wheel. Which for some is to create a "Look" but for drivers it's not advisable for the best handling and Go!





R

Van

I could have sworn the forged rims on my Turbo S were 7J front and 9J rear (with 225 front and 245 rear).

V2Rocket

225 fits on a 7 pretty well.

the root of my searching is to find a summer tire in approximately the correct diameter range (25" or so). i want cornering grip but i mostly want a stickier tire for braking.

by "light on its feet" i dont mean low rolling resistance (like prius tires) but that a narrower tire will steer with less driver effort and sort of "dart around" easier as well as break free faster. i don't corner all that hard compared to many of you, but i do like the occasional tire squeal going round a bend! most of my driving would involve fast "sweeping" turns like a highway curly-Q onramp rather than attacking intersections.

as we know selection in 15" is fairly limited - although i have found a number of 205/55r15 options which are the right diameter, reviewed well, priced well, but i think i'd need a 6 or 7 inch all around setup. certainly not 205s for my 8" wheels.

i wouldnt have considered 17s but i found out that there are several companies making nice looking 17x7 fuchs replicas for very inexpensive so...

924srr27l

Yes, your right 225/50/16 on a 7" !


Porsche must of lost the plot on this fitment decision!


9" wide tyre on a 7" wide rim means an Inch of SLOP either side...


I know they did this on the Large (Tourer) Lardy 928!


I've tried this spec before (Wide tyre narrow rim width) and it affects the handling too adversely for my liking, the car moves around too much and does not feel as direct as I Prefer,


If I replaced all 4 of my 205/55/16 Tyres and fitted 225/50/16's I'm 99% sure the extra weight of the tyre will be noticeable, but also the slop and sidewall flex, you can increase the pressure to help but I've found a sweet spot running 26psi all round so I'd not be interested running 36psi on wider 9" wide tyres and 7" Wide rims.


It's the front that's an issue, on the Rear this set up is not such an issue
Unyet it's bizarre than Porsche's fitment for the rear was a
245mm (Almost 9" wide) tyre on a 9" Wide rim Perfect ! just odd why they went and fitted a sloppy front combo!




R

924srr27l

Best for braking and traction is what you have now, High profile sidewall, and reasonable narrow, but the compounds have to be a high treadwear to cope with the tall Sidewall HEAT, so as you know Sticky is not available.


Aren't the 17's replica's heavy ?


You mention 205/55/15 is the right diameter ? it's too small


Yes narrower tyres do react and Dart quicker, and not always loose grip any quicker but you'll get better Feel with them near the limit, they communicate much better than wider tyres.


For fast sweepers you want Lateral stability, this means wider Rims 8"?


R

V2Rocket

Hadn't thought about the heat capacity..thanks!
I haven't heard back from the MFR about the wheel weight but the 16" replicas are maybe 1/2-1lb heavier than "genuine" so perhaps not so bad?

Yes you are right 205/55 is about 24" the same OD as a 225/50 so it will be small but if its all i can get...

If I could find a summer 225/50R15 or something closer to 25" OD I would stick it on all 4 of my 8" BBS but not having any luck in reasonable tire prices...

I would think that a hard sharp corner needs more lateral than a long sweeper due to the suddenness of the direction change vs fairly constant side load after turn-in?

924srr27l

You could use some Tyre Softer to decrease the treadwear rating a bit, I'm using Michelin Pilot Sport 3 Tyres but they have a reasonably high treadwear rating at 320, but soft sidewalls, I am considering trying / testing the opposite hard sidewall lower treadwear and Bridgestone Potenza has this set up with about 140 treadwear.


I wonder if Europe have a Better selection, shipping from the UK to the US is reasonable the last time I checked?


Wider rims on the front don't turn as quick & sharp, for what tends to e quick direction changes less than 50mph, if you have to turn in hard over 80mph your potentially in trouble.


The last set I tried was unanimously worst, when I went bigger (7 & 8.5J x 17") and 205/50 & 235/45 Tyres.


The car was noticeably slower to accelerate from the lights and also at speed especially from 80mph+ in 5th gear, but also the car was not as sweet at changing direction at all speeds and lastly the ride quality was
poor!


I don't have any wheelspin issues at all so I'm sticking with 205/55/16 all round, I'd only change the wheels now if I found a Magnesium set of 16's


R

Van

I was wrong... my winter tires are 195s.

fasteddie313

This is 205s on 6" gullydeckles..



Good forged fuchs wheels but many people don't like their look..

I like them very much but would like to upgrade to the wider 928 gullydeckles for wider tires because I need more rear traction..