Can we talk FC front wheel bearings

[jwvand02]

I'm running lots of tire (285 super 200s) and some downforce on track and really struggling to keep my wheel bearings alive. They are maybe surviving 3 or 4 events on average before needing changed. I'm also finding that they like to fail VERY fast and take things with them. I think I just ruined a spindle from the preload washer spinning, and I destroyed a hub, brake caliper, rotor and spindle last year from another failure.

I reached out to the only guy I know of that's currently running an FC doing serious grip racing with a ton of tire, and he basically is in the same boat. He changes hubs frequently and often at the track. His advice was to use only timken or OEM bearings and said he does his preload by feel and ignores the mazda directions. When I tried to use the mazda directions, I ended up with way too much preload that caused a bunch of brake shaking. I have been following timken's generic directions which is 50 ft-lb to seat and back off completely, 10 ft-lb and then back the nut off about 60 degrees to preload. It helped the feeling in the car a lot but I suspect is a bit too loose.

FDF makes a drift kit that uses 350z wheel bearings but the geometry is a complete disaster for a grip application.

I also think I might experiment with some extended ball joints and crash bolts this winter to try to get the spindle a little farther inside the wheel. Right now I'm running spacers so that the effective offset of the wheel is something like a +6, I think if I could extend the ball joints like 15mm and use the crash bolts to angle the knuckle away from the strut, I could keep the ~4 degrees of camber I run now and shave maybe 10mm of offset.

I'm curious if anyone has some arcane knowledge on bearing setup or knows a guy that has managed to adapt some more robust spindles and bearings because this is a massive pain in my ass.

[freeskier7791]

Unfortunately it seems like you would have to get new spindles made.  The outer bearing on the FC is pretty small.  Timken bearings will be the best you can get.  I wonder if you preloaded and then had a crush spacer made to allow you to keep the preload constant it would help.

[jwvand02]

Unfortunately it seems like you would have to get new spindles made.  The outer bearing on the FC is pretty small.  Timken bearings will be the best you can get.  I wonder if you preloaded and then had a crush spacer made to allow you to keep the preload constant it would help.

I am pretty tempted to 3D scan the existing spindle and commission a billet aluminum spindle using 350z bearings. I think it would help the loading a lot if I could get the bearing way farther into the wheel, factory cars running this sort of tire have 40-50+ MM offsets. It's just pretty tough to make anything economical for the FC as there is truly only a handful of people grip racing them. 

[shainiac]

This is not exactly what you're asking, but I was able to swap S197 Mustang knuckles onto FC lower control arms and ball joints. I bought Mustang lower mounts for my Fortune Auto coilovers and it "bolted on", but not really. I did not extend the lower control arms and had a lot of trouble getting enough negative camber out of them. I had to notch the upper bolt on the coilover mount, which kind of made the wheel flop when at full lock. The final nail in the coffin was bumpsteer. I couldn't physically get the outer tie rod high enough to dial it out. With zero spacers, it still had 1/2" bump from min-max travel. IF you could figure all of that out, you'd have way beefier knuckle and steel hubs/bigger bearings. I don't think they're a tapered bearing either.

I went through all of that to get factory 14" Brembos. I miss those brakes, but everything else was a boondoggle.

[cholmes]

Having a solid spacer between the inner races can really help. Carroll Smith describes it in his books. This Australian company offers them for "Series 4 RX7", which is FC:

https://msfracingcomponents.com.au/product-category/stub-stiffeners/

Hope that helps!

[jwvand02]

This is not exactly what you're asking, but I was able to swap S197 Mustang knuckles onto FC lower control arms and ball joints. I bought Mustang lower mounts for my Fortune Auto coilovers and it "bolted on", but not really. I did not extend the lower control arms and had a lot of trouble getting enough negative camber out of them. I had to notch the upper bolt on the coilover mount, which kind of made the wheel flop when at full lock. The final nail in the coffin was bumpsteer. I couldn't physically get the outer tie rod high enough to dial it out. With zero spacers, it still had 1/2" bump from min-max travel. IF you could figure all of that out, you'd have way beefier knuckle and steel hubs/bigger bearings. I don't think they're a tapered bearing either.

I went through all of that to get factory 14" Brembos. I miss those brakes, but everything else was a boondoggle.

No, this IS exactly what I'm asking although not as tidy as I would like I am willing to put some effort into figuring out something a little more sustainable, especially if it also gets the mounting face farther into the wheel. I might see if I can grab one of these and mess around with it.

What tie rod ends were you using? Are they tapered? I wonder if some material can be added and re-machine with the taper in the opposite direction.

[jwvand02]

Having a solid spacer between the inner races can really help. Carroll Smith describes it in his books. This Australian company offers them for "Series 4 RX7", which is FC:

https://msfracingcomponents.com.au/product-category/stub-stiffeners/

Hope that helps!

Awesome lead, thank you

[cholmes]

No sweat man.

If they help, please let us know, I don't have wheel bearing problems on my track FC -- yet -- and so I haven't bothered buying them yet.

Endurance 200 TW tires and basically zero downforce is keeping me out of trouble for now but we're getting steadily faster with development. I think I'll be looking at distressed wheel bearings before too long.

I did use similar bearing spacers on Mustang II front spindles & bearings I was using on a Lemons type '88 Fiero a few years ago. Car rolled noticeably easier, brake feel was improved, and zero bearing issues. The very best Fiero hubs I could buy wouldn't even last through one day of Lemons racing, it was comical.

Very common to use bearing spacers in circle track, even in the lowest classes.

[shainiac]

This is not exactly what you're asking, but I was able to swap S197 Mustang knuckles onto FC lower control arms and ball joints. I bought Mustang lower mounts for my Fortune Auto coilovers and it "bolted on", but not really. I did not extend the lower control arms and had a lot of trouble getting enough negative camber out of them. I had to notch the upper bolt on the coilover mount, which kind of made the wheel flop when at full lock. The final nail in the coffin was bumpsteer. I couldn't physically get the outer tie rod high enough to dial it out. With zero spacers, it still had 1/2" bump from min-max travel. IF you could figure all of that out, you'd have way beefier knuckle and steel hubs/bigger bearings. I don't think they're a tapered bearing either.

I went through all of that to get factory 14" Brembos. I miss those brakes, but everything else was a boondoggle.

No, this IS exactly what I'm asking although not as tidy as I would like I am willing to put some effort into figuring out something a little more sustainable, especially if it also gets the mounting face farther into the wheel. I might see if I can grab one of these and mess around with it.

What tie rod ends were you using? Are they tapered? I wonder if some material can be added and re-machine with the taper in the opposite direction.

I used an S197 bump steer kit with the factory Ford taper on studs.
I use BMW E10 inner tie rods.  They're about the right length and M14 on both ends for the mustang tie rod and Mazda rack. The issue I had is that the tie rod heim wants to be right where the pickup exists on the knuckle. You could definitely cut and weld the pickup like drift knuckles are modded. You'd also be able to optimize Ackerman.

[jwvand02]

This is not exactly what you're asking, but I was able to swap S197 Mustang knuckles onto FC lower control arms and ball joints. I bought Mustang lower mounts for my Fortune Auto coilovers and it "bolted on", but not really. I did not extend the lower control arms and had a lot of trouble getting enough negative camber out of them. I had to notch the upper bolt on the coilover mount, which kind of made the wheel flop when at full lock. The final nail in the coffin was bumpsteer. I couldn't physically get the outer tie rod high enough to dial it out. With zero spacers, it still had 1/2" bump from min-max travel. IF you could figure all of that out, you'd have way beefier knuckle and steel hubs/bigger bearings. I don't think they're a tapered bearing either.

I went through all of that to get factory 14" Brembos. I miss those brakes, but everything else was a boondoggle.

Bought an upright on eBay. My first idea is to tig a piece of round stock with a pilot hole drilled on top of the pickup, mill the bottom down, and re-ream the taper. Will also try crash bolts for camber and maybe make my own extended balljoints out of 626 ball joints if I have to. This will be a fun project. In the meantime I'll use the bearing spacer cholmes suggested and see how that goes!

No, this IS exactly what I'm asking although not as tidy as I would like I am willing to put some effort into figuring out something a little more sustainable, especially if it also gets the mounting face farther into the wheel. I might see if I can grab one of these and mess around with it.

What tie rod ends were you using? Are they tapered? I wonder if some material can be added and re-machine with the taper in the opposite direction.

I used an S197 bump steer kit with the factory Ford taper on studs.
I use BMW E10 inner tie rods.  They're about the right length and M14 on both ends for the mustang tie rod and Mazda rack. The issue I had is that the tie rod heim wants to be right where the pickup exists on the knuckle. You could definitely cut and weld the pickup like drift knuckles are modded. You'd also be able to optimize Ackerman.

[shainiac]

You might have better luck milling down the top-side of the tie-rod pickup and adding a second tab above that to bolt a heim joint in double shear. Safer than a single-straight bolt/nut in single shear like plenty of people run. If you spaced the top bracket high enough, you could even fit some shims and still have some bump steer adjustment. What shocks are you using? I still have my S197 Fortune auto coilover lower mounts if they're useful. They're an M52 thread IIRC.

[jwvand02]

You might have better luck milling down the top-side of the tie-rod pickup and adding a second tab above that to bolt a heim joint in double shear. Safer than a single-straight bolt/nut in single shear like plenty of people run. If you spaced the top bracket high enough, you could even fit some shims and still have some bump steer adjustment. What shocks are you using? I still have my S197 Fortune auto coilover lower mounts if they're useful. They're an M52 thread IIRC.

Running RedShift coils, which use BC Racing bodies. I'll have to check the diameter. I missed in your original post that you changed the lower mount so I am glad you mentioned it again.

[largeorangefont]

What is your current wheel/tire setup?

I have had really good luck with wheel bearings, but am only on 275 fronts with about a 1/4" spacer. I have the tires as far inboard as I possibly can.

[jwvand02]

What is your current wheel/tire setup?

I have had really good luck with wheel bearings, but am only on 275 fronts with about a 1/4" spacer. I have the tires as far inboard as I possibly can.

285/30/18 RE71RS on 18x10.5 +25. They need about a 3/4" spacer to fit in the front and fit with a nasty roll/pull and no spacers in the rear. They are as far inboard as I can get them in the front as well.

[largeorangefont]

What is your current wheel/tire setup?

I have had really good luck with wheel bearings, but am only on 275 fronts with about a 1/4" spacer. I have the tires as far inboard as I possibly can.

285/30/18 RE71RS on 18x10.5 +25. They need about a 3/4" spacer to fit in the front and fit with a nasty roll/pull and no spacers in the rear. They are as far inboard as I can get them in the front as well.

We are pretty similar. 275/35/17 here on 17x10.5 27 offset all around. No spacer at all in the rear, just a fender pull. They fit under a Shine 20mm front fender with a 6mm spacer. I run Fortune coilovers and I run a shorter front spring for more tire clearance up front.