981 track wheels, sizes offsets

981 track wheels, sizes offsets

Author
Discussion

neil jdmr

Original Poster:

83 posts

122 months

Thursday 25th May 2023
quotequote all
After a couple of years out in gonna start trackdays again. Prior it was in a rx7 fd on 17x10s with 888s or other similar rubber.

I gather 18s are the wheels of choice down to tyre options. There are so many opinions on this that I'm a little lost. I can go for 987/981/718 boggo 18s which is the cheap second hand option but the sizes are skinny. Other 5x130 pcd options are not any nicer

Id like to get some wheels i actually like, in maybe a 9F and 10R but again not sure what size especially with offsets.

My car is a 981S with the important GTS options otherwise bone stock, not x73.

Are there any other oem wheels in a better/ wider fitment i can search the classifieds for?



Edited by neil jdmr on Thursday 25th May 14:15

ATM

18,957 posts

226 months

Thursday 1st June 2023
quotequote all
I've tried some 987 rims in 17 inch and they do fit my 981s. So if you want to go this route its possible.

I run my car now on standard 981 18 inch rims but with slimmer than standard sizes. I'm running 215 front and 245 rear. These are only 8 inch front and 9 inch rear. So I think if you want wider wheels in 18 inch you'll need to look elsewhere.

The bolt pattern is the same on all Porsche cars so you can swap and change. Offset will be your problem so you'll need to use spacers if you do get imaginative. Mostly it's the rear engine cars which have wide rears but these have a very high offset so will sit very inboard but easily fixed with spacers.

As an experiment I ran my 996 with 4x17 rears while I ran my 986 with 4x17 inch fronts.

I think the newer 718 cars have some 10.5 inch rears but this will be 19 inch. You need to check.

Don't forget the GT4 is basically a 981 and it runs massive wide wheels and track day type tyres in 20 inch. So you could just go that route. I think it uses 235/245 front and 295 rears.

LiamH66

840 posts

98 months

Thursday 1st June 2023
quotequote all
ATM said:
Don't forget the GT4 is basically a 981 and it runs massive wide wheels and track day type tyres in 20 inch. So you could just go that route. I think it uses 235/245 front and 295 rears.
981 and 982(718) GT4 wheels are slightly different from one another in detail design, but size and offset are identical. 20" diameter, 11 J rear, 8.5 J front. For some reason the 981 version wheels as a new spare part were about £1000 a set more expensive than the 982, so the "track day" set for my 981 GT4 are actually 982 original parts. I gather 981 GT4 wheels are no longer available new, so will doubtless be overpriced used.

I'm a huge fan of 18" wheels for Caymans on the road, but have been pleasantly surprised by the wide 20" wheels on the track on Michelin Cup 2 tyres. (Or for that matter P Zeroes in the wet). Pretty forgiving, and provide a massive level of grip without making the car feel "over tyred". I'd keep them in consideration, or at least "other brands" in equivalent sizes.

Beyond that, might be worth researching the GT4 Club Sport race car rim widths and offsets. They were 18" diameter, but I think they were single nut centre-lock wheels carrying slicks. Shared a track with one once. Frighteningly quick compared to pretty much any of the Porsche road cars out that day.

Liam

ATM

18,957 posts

226 months

Friday 2nd June 2023
quotequote all
LiamH66 said:
GT4 Club Sport race car were 18" diameter, but I think they were single nut centre-lock wheels carrying slicks.
Big fat looking tyre wall on the back here. Looks good doesn't it. Gap for caliper at the front looks very tight too. These look like 5 studs but just press room mock ups. I'd assume a 10 inch rear should be plenty big enough but you could go 11 inch.


Snowy999

393 posts

72 months

Sunday 4th June 2023
quotequote all
Look at vehicle fitment guides on the Apex wheels website.

The guide ofr the GT4 was perfect for me and am sure there is a cayman specific section too.

Snowy999

393 posts

72 months

ATM

18,957 posts

226 months

Monday 5th June 2023
quotequote all
Snowy999 said:
Scroll down

Did we all see this -





Street w/ Occasional Track Use

Camber: -2º front, -1.8º rear

Toe: Zero front, 1mm toe-in rear (each side)



Street w/ Frequent Track Use

Camber: -2.5º front, -2º rear

Toe: Zero front, 1mm toe-in rear (each side)

  • A small amount of toe-out can also be used up front to improve turn-in, but it will scrub a little speed on the straights.


Aggressive Track

Camber: -3º front, -2.5º rear

Toe: Zero front, 2mm toe-in rear (each side)

  • A small amount of toe-out can also be used up front to improve turn-in, but it will scrub a little speed on the straights.