keep in mind that a set of adaptors is going to be about 4# per corner, after adding in the studs and lugs. that's probably more than the savings in wheel weight, and at a hefty cost.
as for the rules, it is my understanding that they are not allowed. i know that in scca they didn't allow them when i was racing. i'm sure the others won't let them through either, for the same reasons. i'd have to really search though, and ultimately it comes down to the steward anyway. pca may allow them, as they sort of make up their rules as they go along, based on what whiner protests enough to get his way.
Yeah, I suspect you're right about the weight of the adapters. I've got an email in to a company who sells them asking them about the weight, among other things. If they're anywhere near 4 pounds a corner, they wouldn't be worth it, other than for the fact that they would allow for a significantly lighter wheel, which would be easier to take on and off to rotate. And they're actually not very expensive - only around $36 per. But going this route would offer no performance advantage vs. a set of 993 cups if the adapters really are that heavy.
Please understand that I'm very much in the research phase of this whole idea, and I've definitely learned a ton, and done a bit of myth-busting, so whatever I do will at least be well-informed. Given how poorly documented the wheel manufacturers/distributors listings are, it's even possible that there are some wheels out there that would fit my car that I simply haven't found yet. I need to get some calls into companies like Enkei and see if there are options I've overlooked.
yeah - that's what dan's are. i had a set here that converted small dodge pattern to large dodge pattern, and they were also about the same. the materials weigh what they weigh.
if it makes you feel any better, i am going through the same thing right now on the denal. i am probably going to actually have to buy a wheel and weigh it though, as even the manufacturer is questioning their own data sheet.
AS it seems that you want to buy a certain wheel, and you have done as much checking or reseach as you have, i cannot belive that if you called the company who actually makes the whell and have them give you a money back guarrentee if it does not fit properly. all it would cost you is the return shipping.
yeah - fit isn't the issue for me. it's weight. it wouldn't be a big deal though. i just haven't pulled the trigger yet. i was just commiserating with cloud.
[quote name='Cloud9...68' timestamp='1385219895' post='152752']
Eric,
The problem I'm running into with my staggered set-up is that my front tires tend to wear out a lot faster than my rears, at least at the very technical track where I've done most of my driving. So I'm faced with either throwing away very expensive large 18" rear tires before they're fully worn out, or replacing my fronts more frequently than my rears, and therefore running with different "age" tires on the car at the same time, which strikes me as maybe not the best idea (unless that is a myth, like the inability to swap "directional" tires side-to-side). And yes, I don't think 16" wheels will fit over my Turbo S calipers. Overall, it just seems like a square 17" set-up represents a sweet spot in terms of cost and wheel/tire availability (at least if it weren't for Porsche's use of a bolt pattern that nobody else uses <img src="/forum/images/smilies/968/mad.gif" class="smilie" alt="" />).
In your post #35, you mention several non-Porsche wheels, but do you know for a fact that any of them come in a 5x130 bolt pattern? The only non-Porsche wheel I'm aware of so far that does is the Enkei NT03 that I have now. If only the affordable, 16 lb RPF1 did...
[/quote]
Yes the ones I mention definitely come in a Porsche PCD (at least in 18"). I can't guarantee they all make 17" size though.
the fikse profile-5 and 5s were ones i was looking at. a bit lighter than the HRE. the HRE was stronger though, and going to an 18, i was concerned more about strength more than a pound of weight. were i to go with a 17, i might consider the fikse again. of course, i would also be looking at the HRE C70 with titanium fasteners too.
William,
I've found three wheels in the 17 x 9" size that are 16 lb or less that still appear to be available: The Enkei RFP1, Volk Racing CE28N, and the Weds TC-005. The latter two are forged, and are pretty pricey (north of $500/wheel). According to their companies' listings, they're definitely not available in 5x130, and given that at least the latter two are very low volume, I'd be shocked if they'd make a set in 5x130 just for me, no matter how nice a guy I may be <img src="/forum/images/smilies/968/smile.png" class="smilie" alt="" />. But I do have a message into Rays, who is the distributor for Volk, as I figure it never hurts to ask. I need to do the same with Enkei, as the RFP1 appears to be a very popular wheel among amateur racers, so maybe other Porsche racers have already asked about it.
Flash,
Interestingly, only one Fiske wheel showed up in my master wheel weight spreadsheet, and it wasn't the Profil 5, so it wasn't one that's been on my radar. But as usual, I'm having a hard time finding a single source that tells me the wheel diameter, width, offset, bolt pattern, and weight, and I'm just getting going on a fairly extensive flooring project in my living room, so I don't feels like searching through all the different sources right now to dig up the info. I'll just gather a list of candidate wheel manufacturers, and call them all during the week. Same goes for the wheels Eric mentions.
Have you seen the new - rent to own wheel shops now springing up in Florida. If you pay them off in 90 days, you pay regular retail..after that it works out to 2X the retail price (or more) and if you don't pay, they repo your wheels! Totally serious - I can't make this stuff up. I wish I had come up with it.
wheel enhancement has pretty much all of the info on anything that fits porsche. that being said, i wouldn't waste their time unless i was planning to buy them from them.
"And yes, I don't think 16" wheels will fit over my Turbo S calipers."
Cloud,
Are you referring to the calipers used on the 944 Turbo S or on a later 911 based Turbo? If you are using the 928 S4 caliper that came on the 1988 944 Turbo S, 89 944 Turbo as well as the 944 S2 M030 the factory 16" wheels will fit just fine since that's the way it came from the factory. There was also a forged factory 16" wheel in a 9" and a 7.5 or 8 that weighed about 16 lbs. Thats assuming you have the factory M030 spindles, mounts etc..or it was a M030 car to begin with. It's also assuming that you are refering to a 944 Turbo S and not a 911/996/997 Turbo S. My car was used by Fikse to verify clearance measurements for the 17 inch wheels and 928 brake package. The 17's I have (17/8/9) weigh about 18lbs with steel valve cores and balance weights.
~tom
Tom,
I have the 944 Turbo S calipers. Mine isn't an M030 car, so it uses adapters to allow the calipers to bolt to the stock spindles. Based on your comments, it sounds like the 16" wheels you're referring to will only work with M030 spindles, I assume because of the space consumed by the adapters. I do like the light weight of the 16" wheels, but the downsides are that tire selection is very limited (225 is the widest I saw, doing a quick glance), and the aspect ratios are pretty high as well. Always trade-offs...
Your Fiske wheels sound interesting, though. Are they still available, or are yours something of a one-off deal?
attachment=13428:2011-10-07_12-45-32_109.jpg][quote name='Cloud9...68' timestamp='1385305108' post='152783']
Tom,
I have the 944 Turbo S calipers. Mine isn't an M030 car, so it uses adapters to allow the calipers to bolt to the stock spindles. Based on your comments, it sounds like the 16" wheels you're referring to will only work with M030 spindles, I assume because of the space consumed by the adapters. I do like the light weight of the 16" wheels, but the downsides are that tire selection is very limited (225 is the widest I saw, doing a quick glance), and the aspect ratios are pretty high as well. Always trade-offs...
Your Fiske wheels sound interesting, though. Are they still available, or are yours something of a one-off deal?
[/quote]
Cloud,
Yes and no.The spindles etc. are not a factor af far as the wheels are concerned, yes the adaptor would be a concern. The 16" wheel will fit over a factory installed caliper M030 or no. The 245/45R16 along with a 16x9 factory alloy (16#) would be one of the lightest combos available. 9" wheel with a 245* cross section tire is an ideal tire and wheel package plus the overall diameter is the same as o.e.. Two problems, the availability of the 16" light alloys and the caliper adaptor. Despite what the book says, you can run 16" factory wheels on a M030 968. I did it for about 5 years when I as a/xing a lot. This was just a suggestion as a potentially less expensive alternative.
As far as the Fikses go, they are a three piece wheel are very strong and relatively light. Mine are nothing special and off the shelf. Very popular in the northwest because the manufacturer is/was Seattle based and used to work with the local clubs. It was sold about three of four years ago to a Canadian company. You can find Fikse Wheels on the web. I've had FM 10's (17x8&9) for 10 years with no problems.
Good luck in your "quest"
~tom
*Tire Rack lists 11 tires in that size.
'
i would not run the 16s, if only due to the profile of the tire. track is very different from autocross. the cars are not set up at all the same. i don't want to get into the debates of ax setup, as this always leads to "i did it for years, and so did my buddy" arguments, but in autocross the general rule is that you deliberately want to induce some roll, and have a softer setup, so as to prevent snap rebound issues. on the track you want to eliminate the roll and tighten things up. the 16" tires have entirely too much profile. that will squish, roll, and generate a lot of tire heat, which helps an autocross car, but exacerbated the already huge problem on a track car, as does the narrower rim.
in autocross, you barely get you tires hot. that means you can do pretty much whatever you want. this is a track based car. very different set of conditions.
"that will squish, roll, and generate a lot of tire heat"
Sounds like a book I read in high school study hall.
Comparing a 245/45R16 and a 255/40R17 using nominal measurements will show a sidewall difference of about 1/3 of an inch. (245/25.4 = 9.64 in. x 45 = 4.34) sidewall height, (255/25.4 =10.0 x 40 = 4.0) sidewall height. The design of the bead, bead filler and wrapper material will have more of a bearing on performance than a minor difference in sidewall height. Think Formula 1 tires. Since the 16x9 light alloy wheels are pretty much unobtanium and an adaptor has been used that would cancel out the weight savings I too would go with the 17's, especially since I own 2 sets.
~tom <img src="/forum/images/smilies/968/glare.gif" class="smilie" alt="" />
'
I run 16" on the track (as do a lot of others). I actually prefer them to my 17s as the lighter 16 wheel/tyre spins up faster and is more controlled by the suspension. There is no problem with tyre wall flex, it is more important to run the correct rim width. The main issue with 16s comes down to tyre choice (and brake size limitation).
keep in mind that he is looking at a 35 profile. going to a 45 is HUGE. it's not just the sidewall flex though. he also wants to runs a smaller outside diameter, so as to lower the gear ratio. neither of these can be done on 16, with what's available out there, which is decreasing every year.
if he could find a 9" wide 16, it might make sense, assuming he could also find an outside diameter under 24.5". losing more tire, when he already needs more up front, and then also losing the advantages that the smaller diameter would bring, is going in the wrong direction. i think he would need to re-spring the car, and increase sway bar size a lot.
it would be a lot less expensive on 16s, that's for sure.
i agree with the idea, but availability is likely going to be a big problem
the one thing though that might help him, is that with the 16 he stays within the racing rules limitations. so, if he decides to race, he could dial in the setup for those tires and wheels, and be way ahead of the game, compared to having to learn a new setup.
decisions decisions
If I understand correctly, though, 16's would probably not fit over my existing brake calipers with their adapters. Also, while I appreciate all suggestions, the tire selection in 16" is really limited - most of the ones on Tire Rack are racing slicks, which won't work for me. And interestingly, the few streetable tires available in 16" aren't particularly cheap (about the same as 17").
I fully understand that saving weight at the outer periphery (meaning the tire) is the most important factor. I guess it's more of a philosophical thing with me - I would expect to save at least a couple of pounds per wheel going from my current set-up to a square 17 x 9, but given the available wheels (I need to look more into Fikse - their web site doesn't give much information), it looks like I'd end up with about the same wheel weight I have now. While that may not end up amounting to a hill of beans worth of difference, it just seems wrong.
So what's the deal with Fikse wheels? Their web site give very little information - company history, some verbiage about their manufacturing techniques, and some pretty pictures. No available sizes, weights, offsets, or specs of any kind. No info on who carries them, either. They are very sharp - I like the FM10's on Tom's car the best - and if they're a little lighter than Porsche Cup (whatever that means...) wheels, so much the better.