Spacers & Wheel Offsets...

Hi All, I'm putting winter tires on my stock Twist wheels (18x8et50f, 18x11et45r) on the C4S. I'm looking to pick up some wheels for the summer - looking at the Lobster Forks (19x8.5et57f, 19x11et67r). What size spacers should I looking to get? 7mm front, 22mm rears? Or should I go with the 5mm fronts and 15mm rears? I think I may be able to source the latter sets cheaply, but would it fill out the wheel wells adequately? Should I just bite the bullet and pick the former? I've tried searching the forums and haven't come across the information I need. Thanks in advance!

For an 8.5" front wheel you want to be somewhere near et40 for an ideal offset. That's the width and offset used on a GT3 wheel. For an 11" rear around et63...again GT3 reference since those are stock widths on the GT3 wheels (despite the diameter difference with the lobster claws). Andy

So you'd recommend going to 15mm spacers in front and 5mm in the back?

C4S right? ET40 front yes, 15 16 17 mm spacer will all be fine ET63 rear no, 5mm spacer and you still probably don't clear the brakes. You'll be nearly an inch narrower than stock out back. Rear for an 11 you'd be looking at at least a 25mm spacer for ET42 (for 11s in widebody offset turbo et45, technos et47, and I would say 35 to 38 is max for 11s on widebody depending on tires, ride height etc, and ET63 is about max for narrowbody 11s) Honestly I don't think that's worth the effort unless you're getting the wheels extremely cheap, several hundred dollars of long hubcentric spacers in your future Have you considered a set of widebody wheels? I would try to talk you out of 19s, but I've been so far down that road I know that nothing will stop you, however do note that anecdotal testing on the AWD drive cars in particular indicates that there may be some good reasons to stay at 18, again particularly with the AWD cars

I'm sorry I didn't look at your sig and realize your car was a C4s. the above is correct...you're going to need a pretty big spacer to make them work. When you figure that spacers + bolts are going to be around $350-400 total it might just be more worth it to find a wheel that's a touch more expensive and you can get away without needing the spacer. Andy

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Thanks for the information - I'll keep my eyes peeled for some widebody wheels. I had a line on some well price lobster forks and for some reason really like the look of them. htny - What would the reasons be? Something specific to the C4S' AWD system? I've had AWD cars for a long time and never heard that 19's would be problematic..

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Usually, the lobster wheels are considered the fugliest off all.... Ive never seen them in WB format....

^^^ BAWAHAHAHAAAAHAHAHAH

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That could be a lot of people's opinion - but the thing about individual taste is not having to submit to the opinions of the herd, only your own!

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Rajesh, again I must say it's anecdotal, not a matter of fact, but many people believe that it has to do with the more complex AWD drivetrain being more sensitive to changes in the amount of force being generated, since it can't be attributed to rolling diameter or absolute weight as those can be made the same, and apparently similar irregularities have been experienced by some on 18" running slicks. It's hotly contested, there are plenty of people who claim the are fine, and seems to only affect the vehicles as they approach the limits, so many will state there is no disadvantage to the 19s on a AWD car, stating that their cars feel better in "spirited" driving, which I've come to suspect only means that they aren't short shifting that day. Look, If limit handling becomes unpredictable, it's a safety issue, because when you need the car to work the most, accident avoidance, over uneven pavement or a patch of leaves or a slick road, emergency situations, it may not behave the way it should, or they way you expect. There was an article in one of the magazines on this a while ago, I will try to dig it up. edit: found it http://www.europeancarweb.com/featur...est/index.html Of course, there's always the possibility that the tires weren't mounted properly or were brand new, unshaved/not up to temp, the wheels hubs weren't plane, they were very far out of balance or round, but considering the circumstances and the vendors it's not very iikely, unless they've never tested a tire. One last thing you should look at: the cost of 18" tires and, for Canada, the availability of 19" All season rated (as opposed to summer) tires in aspect ratios that will leave you within rolling diameter tolerances. My advice to you is to consider the purpose of the upgrade, especially on an AWD Porsche in Canada. If it is for looks alone, there aren't many people who aren't complete and total wheel nerds who can spot the difference between an 18 and a 19 at more than 10 feet away. It's a half inch on either side of center. What makes people think they look better is that they look marginally bigger in relation to the wheel well opening. Put the same 19 on the car and jack up a corner and it will look like a 15. Moving to a lower ride height with a good, well tested aftermarket or OEM upgrade suspension would be a much better step to reducing the size of those openings, achieving an aggressive look without the same risk of compromising handling at the limit, or at the very least avoiding big tire replacement and wheel straightening bills. But don't go out and cut your springs! If you do go down this road, a great resource would be the turbo forum over at 6speedonline.com , a lot of plus sizing experience -Hans

here is my (well the one I found) handy dandy tire/wheel offset tool it really gives a nice graphic display of the changes from current to "wanted" and at the bottom gives details of what the changes mean.... TOOL LINK how is the car treating you ?? Ed

Hey Ed, I haven't had much time to drive it in the last couple of weeks - between work and the terrible weather out here, I haven't been able to get out much. I picked it up from Barrier a couple of weeks ago, but my flight got in later than expected and I was lucky to get to the US Export counter just in time before it closed. I've just put on some winters yesterday, and the car feels more planted in the mornings when the temps are rather low...