What is optimum wheel width and offsets for GTS
#16
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The widebody Carrera III rear wheels do fit nicely but the stock 38mm spacer has to be changed.
The thread Hilton mentions concluded 17mm would be ideal but that size is not readily available so I took Chucks advice and sourced 15mm spacers that fit with the long stock studs.
The thread Hilton mentions concluded 17mm would be ideal but that size is not readily available so I took Chucks advice and sourced 15mm spacers that fit with the long stock studs.
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#18
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Holey BeeGeeBees, had no idea custom wheels were going to take so looong. It's been over three months.
Seems the guy that was handling my wheels got fired because he was telling people he was working on their wheels and wasn't. Seems the rim pieces were not even ordered yet.
Still waiting on the 3 piece rim pieces to come in from the wheel shops supplier. The thin outer rims to get the correct offsets seem to be the slowdown.
Seems the guy that was handling my wheels got fired because he was telling people he was working on their wheels and wasn't. Seems the rim pieces were not even ordered yet.
Still waiting on the 3 piece rim pieces to come in from the wheel shops supplier. The thin outer rims to get the correct offsets seem to be the slowdown.
#21
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I am working on this at the moment. L/story: We got the 18x11 WB 911 wheelset for my bud's 911C2. But the tire shop wouldn't stretch fit 265's snows that came with them. Sooo, I got him a set of replicas (18x8,10) for the snows and took the WB twisties for the 928GTS.
I first put them on for a test fitment and of course the huge GTS spacer punts out a ET45 wheel.
So I removed the stock spacer and mocked up a 20mm spacer depth using Acetal from our shop. Open ended lug nuts will work to mount the wheel (I can cut tops off of stock nuts). Then I thought why not follow those up with another set of nuts just to cap things off. Like a double nut. Either that or a plastic cap for the wheel stud end.
I'll update pix with the new mock fitment tomorrow. I have ordered 20mm spacers. Fronts are 18x8 ET 50's.
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I first put them on for a test fitment and of course the huge GTS spacer punts out a ET45 wheel.
So I removed the stock spacer and mocked up a 20mm spacer depth using Acetal from our shop. Open ended lug nuts will work to mount the wheel (I can cut tops off of stock nuts). Then I thought why not follow those up with another set of nuts just to cap things off. Like a double nut. Either that or a plastic cap for the wheel stud end.
I'll update pix with the new mock fitment tomorrow. I have ordered 20mm spacers. Fronts are 18x8 ET 50's.
#23
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Well you can mount these things on a 928 but with a 8 inch ET50 up front I am always left wondering why bother? Up front you need ET65 to support the design as Porsche intended with the correct amount of NSR- however your choice of course.
For the rears it is simply a matter of geometry and presumably you are going to run a 295 section [or a 285 section if I read the chalk marks on the tire correctly- that should work fine albeit a 285 sits better on a 10 inch rim like mine. When it comes to rear offsets you simply have to compensate for the offset and section width combination. For instance I run a 295x30x18 section on the rear ET60 x 10 inch rim and this fits perfectly. I can run the same wheel wiht the stock 38m spacers but in my opinion it is way too close to the fender even with -1.5 of camber and rolled arches and I felt that under hard cornering there was some rub taking place given static conditions and dynamic conditions are not the same- the various components flex- that is a certainty- the unknown being the actual amount [not too much].
I think the offset/spacer combo you are proposing will work but you will not have much clearance from the fender. If you find something suitable to cap the protruding wheel studs please post details.
Rgds
Fred
For the rears it is simply a matter of geometry and presumably you are going to run a 295 section [or a 285 section if I read the chalk marks on the tire correctly- that should work fine albeit a 285 sits better on a 10 inch rim like mine. When it comes to rear offsets you simply have to compensate for the offset and section width combination. For instance I run a 295x30x18 section on the rear ET60 x 10 inch rim and this fits perfectly. I can run the same wheel wiht the stock 38m spacers but in my opinion it is way too close to the fender even with -1.5 of camber and rolled arches and I felt that under hard cornering there was some rub taking place given static conditions and dynamic conditions are not the same- the various components flex- that is a certainty- the unknown being the actual amount [not too much].
I think the offset/spacer combo you are proposing will work but you will not have much clearance from the fender. If you find something suitable to cap the protruding wheel studs please post details.
Rgds
Fred
#24
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OK so call me stupid well I may have it coming but i have an 86.5 and would like to know what it would take to make these work, 11+18 et45 and 8 +18 et50 work on it. I (of course was told they would work)Ray sorry to go off course.
#25
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When GTS rear bearings need to be changed anyway it makes sense to change long studs to same size what is used at front axle. After this its much easier to get correct fitment with bolt on spacers than trying to work with original setup. After the change only 7 to 14mm area is the problem since there aren't that thin bolt on spacers and slip on can't be thicker than about 6mm to allow enough thread on nuts for safety.
#26
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Okay so I found these 2 pc wheels I really really like, BUT... They are 18x9et50 and 18x10.5et44 and would stick out way more than I want to try to deal with fender wise.
Getting a great deal on these rims and since they are 2pc I can have them re-barrelled. The best re-barrel deal is on 18x8 and 18x10 what are the optimum offsets of 8s and 10s. My Carrera IIIs are 18x8et57 and 18x10et58.
Photoshopped fitmet...
![](http://www.zipbang.com/928gts/roockwheels.jpg)
![](http://www.zipbang.com/928gts/roockongts2.jpg)
After I get these wheels on I will have a set of Carrera IIIs available for sale.
Getting a great deal on these rims and since they are 2pc I can have them re-barrelled. The best re-barrel deal is on 18x8 and 18x10 what are the optimum offsets of 8s and 10s. My Carrera IIIs are 18x8et57 and 18x10et58.
Photoshopped fitmet...
![](http://www.zipbang.com/928gts/roockwheels.jpg)
![](http://www.zipbang.com/928gts/roockongts2.jpg)
After I get these wheels on I will have a set of Carrera IIIs available for sale.
#27
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I'm really liking these 996 18's. For looks at least as I have yet to drive them of course.
Design wise - they provide a nice link between stock and modern, without being too overdone. The simple rounded body of the 928 series can be reflected in a simpler smooth wheel. And with its flush spoke and 18" design, plus the offsets, fill the 928GTS's arches & the bill nicely. The stock wheels look anemic in comparison!
Scrub radius IIRC minor inconvenience - I used to run ET50's on my 1990S4, noticed a little bump steer i guess. Not too worried about that. Going wider at the front you'd want to match that at the back to keep the same dynamic edge/turn in response. So not to upset that nice staggered stance of the GTS. That was the biggest difference for me on the GTS. The rear axle felt cool, handling sharp - a lot more like the 996 I just drove this weekend.
Design wise - they provide a nice link between stock and modern, without being too overdone. The simple rounded body of the 928 series can be reflected in a simpler smooth wheel. And with its flush spoke and 18" design, plus the offsets, fill the 928GTS's arches & the bill nicely. The stock wheels look anemic in comparison!
Scrub radius IIRC minor inconvenience - I used to run ET50's on my 1990S4, noticed a little bump steer i guess. Not too worried about that. Going wider at the front you'd want to match that at the back to keep the same dynamic edge/turn in response. So not to upset that nice staggered stance of the GTS. That was the biggest difference for me on the GTS. The rear axle felt cool, handling sharp - a lot more like the 996 I just drove this weekend.
#28
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Before someone shoots that down. The Weissach design made the car handle like it had a wider rear tire by toe in. If you are going into a static curve a spring rate change won't unsettle the car enough to cause the Weissach to come into play. However turns that are static curves that turn into a sudden decreasing radius curve then the spring progresses to the next level on one side affecting the Weissach. If you are running anything more narrow than a 305 you won't see or feel it as much anything over that will cause some pucker in the driver seat.
This is exactly why people go from eibach back to stock or to other linear rate spring and also why the weissach gets pinned too.
so keeping the suspension and breaking bias and overall handling, in mind make sure you aren't causing one problem while not really solving another problem.
In other words you can go wide. I wish I had gone 8.5's on the front instead of 9's.
#29
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Drove it around a bit to settle the shocks. The wider-spaced front not a problem, a few steering tweaks here and there over bumps but insignificant really. It centers more strongly if anything, which is nice. Explains the reason it was pulling to the stock wheel side when I had one and one. Something related to the offset/height or camber.
I had the rear a bit up there on worn-in 17's (reasons- sunroof driving position (too low, I hate it), and rear susp travel on wavy roads) now with the beefcake rubber back there need to lower.
I had the rear a bit up there on worn-in 17's (reasons- sunroof driving position (too low, I hate it), and rear susp travel on wavy roads) now with the beefcake rubber back there need to lower.