[BFlanagan98]

Hi again guys,

Assuming a track-prepped car, 2.2ish negative camber, and a fair bit of roll stiffness, has anyone tried to fit an 18x10 et65 wheel on the front?I assume it'll be really tight, but might it clear? 265/35R18 tire mounted on it. Rear is easy but I'm trying to find a cost effective solution for up front that doesn't involve high dollar custom made wheels. Has anyone tried it?

Brian Flanagan
Possibly Deranged

[worf]

10-inch ET 65 is going to stick out by about 1.25 inches.

You'll probably need to put in an extra spacer on each of the steering rack arms to limit rotation.

And that, probably even with custom wheels with an ET that moves them inboard.

9" ET 68-ish with 255 works well but still could use a spacer on the rack arms.

[BFlanagan98]

Thanks Worf, you always seem to have the info I need!

Some time spent googling the Other site and it looks like that's a no go if I like my fenders.

Oh well. Back to the ol' drawing board.

[worf]

Some time spent googling the Other site and it looks like that's a no go if I like my fenders.

That's certainly true if the rolling diameter of the tire is more than a c**t hair bigger than stock.

Mark Anderson's race cars had bespoke fenders to fit the meat.

255 on a 9et68 is a sweet spot.

[maddog2020]

machining the spindle to the 944 profile and using the 944 hub brings the mounting face inboard 15mm on each side. I'm currently running 9" on the front but with the current setup I could go to 10's easily. My fikse FM10's fit before the spindle mod, and since I moved it inboard 15mm, and the outboard side was 15mm wider that's 30 mm and an inch is 25mm. I do have the 2.5 inch springs which would be a must as well, but an 18x10 can fit without fender mods. It's not cheap but it can be done. oh and the diameter of my tires is 26 inches give or take.



With the above mod you will be changing the distance from the rotor mounting point to the plane where the rotor fits in regards to the caliper so you'll also need to go with different rotors and it's a perfect time to upgrade to 355mm front rotors and bigger calipers. Roger has the rotor hats in stock, and you can use Brembo or stoptech rotor rings, and can choose between slotted and holed rotor rings. There are multiple caliper options out there, the cheapest being Audi A8 and Audi S8 calipers which can be found on ebay used from time to time. Brembo also makes a bolt on version with spacers but I'm not sure about the cost or part numbers. There are complete brembo kits and then you could swap out the rotor hat that Roger sells for the rotor hats that come with the brembo kit.

[BFlanagan98]

This is definitely gonna be a slippery slope...

Do you have any more details/links to machining the spindles to 944 specs, and the assorted other bits and pieces needed to make that happen specifically?

[maddog2020]

944 hubs are here:

https://racersedge-inc.com/m030-and-sta ... urbo-hubs/

Rotor hats are here:

https://928srus.com/products/s4-gt-gts- ... 13&_ss=r44

Suspension hats are here:

https://928srus.com/products/front-rear ... bd13&_ss=r

Threaded collars and sleeves are by coleman racing


When it comes to machining the spindles the 944 and 928 use the same inner and outer wheel bearings. the 944 hub just moves them closer together. You can also remove the abs rings from the 928 hubs and put them on the billet 944 hubs. I wouldn't recommend used 944 hubs as they are known to crack and that is why there are billet versions out there.

Springs are standard 2.5 ID springs and are 8" length in front and 12" in rear. I can post more info tomorrow.

[worf]

I gotta ask... is doing the "negative spacer" work cheaper than having Augment make a custom set of wheels?

All-in: parts, machining, labor value.

[maddog2020]

I haven't checked the price of custom wheels lately. Converting to the 2.5" springs would still be needed, and the additional benefit of the 2.5" springs is that you can change springs to get different rates without having to have a compressor, so if you want different rates for different tracks then it makes it easy. Custom wheels can only compensate for so much. When you look at the relationship of the outer tire bead to the wheel mounting surface, there are limitations in design when it comes to strength. A lot of aftermarket/custom wheels can't be made that thin due to structural reasons. My Fikse FM10s are like this. all Fikse wheels stick out more than 1/2" in the front due to the wheel designs and the constraints for structural strength. If you wan to have the best possible scrub radius AND keep the stock fender line you have to move the hub, however this is only part of the solution. I went the negative spacer route for exactly this reason. Unless there is some perfect factory wheel out there, then custom wheels are going to the other part of the equation. like I said it's not cheap, but when you set physical criteria like keeping the front fenders stock it is what it is. the room for a wider wheel has to come from somewhere.

[worf]

all Fikse wheels stick out more than 1/2" in the front due to the wheel designs and the constraints for structural strength.

Mine do not. Not a 1/2". Maybe 1/4" or less.

I fail to see why Fikse - having "forgotten" how to make 928 wheels - changes things mathematical. If a wheel sticks out by 1/2" in needs 12.2mm more offset.

When you look at the relationship of the outer tire bead to the wheel mounting surface, there are limitations in design when it comes to strength. A lot of aftermarket/custom wheels can't be made that thin due to structural reasons. My Fikse FM10s are like this.

You suggest then, that there is a practical limit to offset and that the limit is lower for a three piece wheel that doesn't weigh a ton.

This makes sense. You don't want to bend a wheel barrel whenever you go over an expansion joint. And a 12" wheel with ET 110 is going to have a lot of wheel barrel on the inside to bend.

But... then there is also a practical limit to front wheel width if you want to maintain useful negative scrub radius.

[maddog2020]

take a plum bob and measure the distance from the front fender lip to a stock wheel then do the same for any Fikse wheels. I've had 3 sets and they can only make the hubs so thin on the wheel center.

I'm not concerned about the barrel or bending them at least as far as this conversation is concerned. The wheel makers look at the strength around the hub as a liability in regards to safety and legal concerns. Fikse changed hands several times, and so the new owners only trusted some of the thicker designs, and if you have a really old set of Fikse's and they are the older thinner style there have been issues with cracks and they won't make replacements with the same dimensions.
All of my focus is geared towards getting the right scrub radius. It makes no sense to go with an ultra wide wheel , and not have the optimum scrub radius.

[BFlanagan98]

Thanks guys, as always you guys are a wealth of information!

@maddog2020 Thanks for the links. I'm already on 2.5" springs so that part is handled. Just bought a used set of 8.5" et53 OZ wheels to use for now that I think will fit ok with camber and a roll, but my ultimate goal is to go 10" or more all around. I'll be digging into the info you posted to figure out a possible path forward here that makes sense for me.

@worf I've been speaking with the guys at KRNC Forged about making custom wheels. 18" one piece are $2200 or so for a set built to my specs, using one of their available designs. I also spoke with my guys at Apex Wheels (I'm a dealer for them) about making an 18x10 forged wheel to fit 928 up front (or all around with a rear spacer) but they need to do 20 pieces for a run, and I don't need 6 sets of wheels!

[worf]

@BFlanagan98 Thanks for putting it out there. 10" front wheels are not on my priority list right now though.

[maddog2020]

I thought I'd update this thread on the Fikse wheels since I'm now a dealer and have more info than I did when I posted back when this thread was written. My current set of wheels were made in 2008 and at the time Jim Fikse had set a minimum pad distance due the design and changed it sometime before 2008. Fikse closed their doors in 2009 while Jim Fikse was the owner/founder. The current owners have resurrected the thinner pad designs not just for the 928 but for other cars as well. My wheels were made with the thicker pad design and while they fit I was not happy with the look. This issue appears to have been resolved.