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Is a Cup 2 8 inch Wheel with ET 70 a good option in the front with 235/40 R 17?
This is the setup I have for sale, so yes, they fit. But, I'd put a 235/45 vice 235/40 on it, as it will more closely match the likely rear diameter and work better with the ABS sensor.
By my calculations 9.5 with et68 would result in the tyres making contact with the arch, it might work on a 8.5, are you sure about those sizes?
I am running an 8.5 et60 which struggles to fit in the arch.
What camber and what section width are you running on your wheels?
I have been running my wheels for some 14 years and on both my late 90 S4 and my current GTS. In both cases I run with more camber than stock, I run at the bottom end of the Porsche recommended ride height and typically run a 265 section. My wings are also rolled but nothing excessive or silly. I have run with camber in the range of 3 degrees down to my current alignment which is about 1.5 degrees as I am currently running a 255 section up front. 1 degree of front camber is just not enough with that amount of grip.
The only contact issue I had was tyre rub on the Devek roll bar at full lock- I resolved that by fitting an additional spacer at both sides of the rack to restrict lock a bit. Never had any turning problems but then I do not have to negotiate those dammed awful NCP car park ramps in the UK! Also, if one runs lower than 170mm up front I reckon one needs stiffer springs such as the Eibachs I run with to compensate.
9.5 et68 would be 15mm further out towards the arch hence my question over the correct et number. Maybe the camber is helping squeeze them in?
As you can see from the photo there is a lot of clearance on that pic- I suspect the rubber used on that installation will be a 255 section. A ET68 wheel will put the wheel centre 2mm further outboard and the 1/2 inch wider rim will add a further 1/4 inch or 6.5mm - a nett increase of about 8.5mm. 265 rubber on the ET68 will sit 7mm further outboard and from inspection of that photo should not cause a problem.
When I first fitted my wheels there was no issue relative to the wings when running just 1 degree of camber.
I have not measured my camber but I am running negative using about 2/3 of the camber adjustment range on the track control arm.
I am still marginal for rubbing on the wheel arch however I have not rolled the arch and don’t want to if possible. I am running 225 on the front which I put on to minimise rubbing until I understand more about clearances. Once I feel I have a better understanding of set up I intend to raise the section width to something like 255. I also choose to run slightly higher profile for comfort reasons which adds to the clearance challenge, in hindsight I would have stuck to the 25” diameter not 26”. I will switch them to 25” at the same time I change the front profile.
I discovered once I fitted my new wheels that one side of the front geometry was all over the place. I had not looked at the geometry in any detail prior to this as there were 100 other job to do. I could visually see one side was sitting with neutral camber and the wheel was set towards the rear of the wheel well.
Hi,
A little off topic but stiil regarding wheels!
Are the later GTS 17" Cup 2 wheels a direct fitment on a early 1983S Euro or do I need spacers?
I know they are very hard to find and very expensive, so I'm asking just in case I win some lottery prize
I have not measured my camber but I am running negative using about 2/3 of the camber adjustment range on the track control arm.
I am still marginal for rubbing on the wheel arch however I have not rolled the arch and don’t want to if possible. I am running 225 on the front which I put on to minimise rubbing until I understand more about clearances. Once I feel I have a better understanding of set up I intend to raise the section width to something like 255. I also choose to run slightly higher profile for comfort reasons which adds to the clearance challenge, in hindsight I would have stuck to the 25” diameter not 26”. I will switch them to 25” at the same time I change the front profile.
I discovered once I fitted my new wheels that one side of the front geometry was all over the place. I had not looked at the geometry in any detail prior to this as there were 100 other job to do. I could visually see one side was sitting with neutral camber and the wheel was set towards the rear of the wheel well.
Check all the front suspension torque values. I had a very dangerous situation occur where my front control arm mounts were very loose. The car had so much toe out that it was stable, but when I had it aligned and they didn't catch the looseness, it would switch from toe in to toe out based on load and snap steer. You may have some loose items if they haven't been checked recently.
I have not measured my camber but I am running negative using about 2/3 of the camber adjustment range on the track control arm.
I am still marginal for rubbing on the wheel arch however I have not rolled the arch and don’t want to if possible. I am running 225 on the front which I put on to minimise rubbing until I understand more about clearances. Once I feel I have a better understanding of set up I intend to raise the section width to something like 255. I also choose to run slightly higher profile for comfort reasons which adds to the clearance challenge, in hindsight I would have stuck to the 25” diameter not 26”. I will switch them to 25” at the same time I change the front profile.
I discovered once I fitted my new wheels that one side of the front geometry was all over the place. I had not looked at the geometry in any detail prior to this as there were 100 other job to do. I could visually see one side was sitting with neutral camber and the wheel was set towards the rear of the wheel well.
With a 225 on an ET60 wheel you should be no where close to being in contact anywhere.
Clearly you need to get your alignment sorted and then you will be in a position to know what is actually going on. Compared to zero camber, minus 1 degree pushes the wheel in about 5mm at the tread in round terms. With an 8.5 inch rim ET60 you should easily be able to run with a 245 section up front and that will work nicely for street use.
I've got the tires mounted on the wheels. It was not easy. While the rims are within the manufacturer's recommended width for the tires, the low profile and stiff sidewalls make it very challenging to get them mounted on the rim. And the large safety bead on the rims made it very challenging to get the outer bead to seat. I ended up marking up the edge of one of the rims in a couple of spots as I worked out the best way to get the outer bead onto the rim. Very unfortunate, but it can be touched up. I've put tires as big as 38" in diameter on rims with my tire mounting machine, but it was a bit challenging to get the 285 wide tires onto these rims. Doable with a little creativity, but not as easy as most other tires that I mount.
My point in sharing this is that if you are putting similarly sized tires (or wider) onto Carrera III rims, make sure that you take it to a tire shop that really knows what they are doing, has the right equipment, and will stand behind their work in case they scrape a rim or rip a bead on the tire. This is not an easy combination to make work. The particular tires that I mounted supposedly have very stiff sidewalls, so that definitely contributed to it.
Anyway, that's my input on the mounting part of the operation. I'll balance them on my dynamic balancer in the next day or two, and then put them on the car. Below are a few photos.
I'm happy to share more specifics on what it took to get them mounted and the beads seated, if that would be useful information for someone.
Tires and wheels ready to be mounted:
One of the wheels:
Bolt in aluminum valve stem that I found that closely matches the color of the wheel:
Inside portion of the valve stem, mounted in the wheel:
Outer portion of the valve stem, mounted in the wheel:
Tires mounted, beads seated, cleaned up and ready for balancing:
Another view of the mounted tires, ready for balancing:
I got the tires balanced. For the most part, they took very little weight. If I were doing a static balance, a couple would have needed zero weight, and the other two needed about half an ounce. However, given that I did a dynamic balance in aluminum rim mode, they all took some weight to get the left to right balance perfect. One of the tires seems to have a high spot, so I'm not sure how that is going to work out once I get some miles on it.
Anyway, they fit on the car. The front tires look like they will stuff into the fender just fine once the suspension is compressed. The rear tires definitely fit, but I don't like how far inboard they are. If they were out by about 20mm, I think that they would look perfect. But, this does mean that 305's would definitely fit in my rolled rear fenders.
So, I'm going to take some precise measurements on how far out I want the rear wheels to be, versus how much extra thread I have on the studs, and find some spacers to achieve the look that I want.
The center caps fit with no problem at all. Overall, I'm happy with the looks and fitment of the wheel and tire combination, given the cost of the wheels. I don't know how the setup will perform, but I hope to get it out for some autocrossing this year.
Anyway, photos are below. I apologize for the the non-picturesque setting and the dust on the car. Also, the picture quality isn't the best. I'm waiting on some parts for the timing belt job that is half done (everything apart), so it will be another week or so before I get better photos.
Right front fender, as viewed from in front of and above the wheel, in line with the body panel:
Right front wheel (before suspension compression):
Right rear, from below and forward of the wheel:
Right rear wheel from behind the wheel:
Right side of car, before the suspension is compressed:
How about the below wheel in high gloss black?
Anyone ever used Braid wheels on our cars? Fed the specs for the boxter wheels I'm running to a guy at Rennline today ...looking at getting a high gloss black version of the one above...they make most wheels to order so sounds like would be pretty decent idea...
Would love to hear any opinions on durability...do they stand up to potholes at highway speeds? They're supposed to be really tough...
What size and model are the tires? My new rears are ET58 and 0.5 inches narrower than those at 10" wide, but I put 285's on them that have an 11.2" cross section. Mine fit with room to spare all the way around. I can take photos of the clearance between the tire and the suspension this evening if that would help.
The wheel fitment calculator spreadsheet says that if you put 255's on those 10.5" rims, they will fit in stock rear wheel wells.
So, the real question is, what make, model and size are the tires, so that you can look up the section width. Or, what tires will you be putting on them?
The calculator says I should be fine with 235/40 up front and 275/30 in the back - which is what I was thinking since many are using this size for the Panamera rims. I haven't gotten to the point of picking tires. I found a thread that discusses these rims but there is a mention of rolling the rear fenders - not something I want to do.
06-08-2018, 02:21 PM
