[Desertnate]

While running a autocross event this last weekend in my F32, I noticed abnormally heavy tire wear on the outer tread blocks of my front tires and 2~3 small chunks (pea-sized or smaller) missing from the same area. My rears don't show any damage, but you can tell the outer edges of the tread are taking a beating as well.

The tires are about worn out in general and I'm looking at replacing them, but I can't help but think a change to the camber at both the font/rear will be helpful. I'd like to hear your thoughts on adjustments.

A little more background.

- The tires are PS4S's which seem to have rather soft sidewalls, so I'm constantly marking the sidewalls/tread edges with chalk to keep track of the wear and air pressure. I have to run nearly 50PSI up front and around 45~47 in back to keep wear off the sidewalls

- This is only my second full-ish season in the car and I ran a partial season before that in a GTI. I'm not a novice, but I've got a way to go skills-wise. I fully admit I'll often brake too late and need to learn the art of trail braking to cut down on oversteer into the corners. I am starting to hit the point where I'm starting to see marked improvement each run and marginal improvement each event. The nut between the seat and the steering wheel still needs a lot of work.

- I'm running bone stock and will stay that way. The car is my daily and the road trip car now that we're a partial empty-nest family. I don't want to do anything crazy, which I understand means compromises.

- I autoX as a hobby, and I'm not gunning to be a top competitor. If I was, I'd ditch the F32 in a heartbeat and get a Miata. It would be much easier, cheaper, and more fun.

- I'll keep running performance tires, but not 200-wear rated. Again, if I was to be serious enough to get a set of dedicated wheels/tires, I'd do it in a different car. This does mean compromises.

So, besides fixing the driver any alignment tweaks which might improve handling/tire wear, but not sacrifice every-day drivability?

A local speed-shop which sponsors our local SCCA chapter and owned by a top regional (maybe national) competitor in his own right (along with his daughter), will do the tires/alignment. I'll pick his brain too, but thought I'd ask this seasoned group too.

[FaRKle!]

BMW makes front knuckles for the car that give you an additional -0.5deg camber. Not sure what else is allowed to change in your class.

[Desertnate]

Originally Posted by FaRKle!

BMW makes front knuckles for the car that give you an additional -0.5deg camber. Not sure what else is allowed to change in your class.

This is an OEM part?

F-Street, or really any of the SCCA street classes are pretty restrictive. I know you can go 1" wider on the wheels, and a few minor changes to things like one roll bar (not both and within a size range) and other suspension bits. Replacement parts have to be OEM spec (i.e. I can't run drilled/slotted rotors), but I think you can "class up" brake pads. I'll have to look at the rule book again to see if new knuckles would be allowed.

I'm not running in the regional or national tour, so I doubt anyone would ever inspect my car close enough to know the difference, but I still want to do my part in keeping some integrity in the classing system.

[FaRKle!]

Originally Posted by Desertnate

This is an OEM part?

No, not OEM, it's OE/genuine. It's a pretty well known mod in AutoX circles.

[Desertnate]

Interesting. Thanks.

There are only 2~3 BMW's which regularly run in our SCCA region (including mine) and we are all bone stock running in F Street with me. Pretty sure the 30-ish Miata owners who show up won't be much help.

There is one guy with a modified 135 that shows up occasionally. I'll talk to him the next time he's at an event and see what he's done.

Based on my read of the rule book last night this mod would probably push me out of Street class, but it might be worth it.

[ClevelandBeemer]

Originally Posted by Desertnate

This is an OEM part?

F-Street, or really any of the SCCA street classes are pretty restrictive. I know you can go 1" wider on the wheels, and a few minor changes to things like one roll bar (not both and within a size range) and other suspension bits. Replacement parts have to be OEM spec (i.e. I can't run drilled/slotted rotors), but I think you can "class up" brake pads. I'll have to look at the rule book again to see if new knuckles would be allowed.

So regarding camber, there is nothing you can do other that the camber correction hubs. There is no other OE part offered for the F32 that will improve your front camber. If your F32 is xDrive then forget about adding camber. You will significantly increase your risk of snapping front drive shafts.

In terms of other parts. You actually can use slotted/dimpled rotors. They were an option offered on the F3X cars. The M-Sports catalog has a few options you can take advantage of. The M-Sport brakes and the M-Sport differential. If it were me I'd do the differential all day long as you will experience significantly more benefits than the BBK. Bigger brakes are not needed unless you are doing extend time on a race circuit link Road America or VIR.

My recommendation, get a 1" wider set of wheels and some Bridgestone RE-71R's. Probably the best bang for buck upgrade you can do. Not only will it make you faster but it will save you money by saving your PS4S's. You can also do the BMW hubs as well and still stay in F-Street.

I AutoX my daily driver 2013 335i M-Sport. My only suspension related mod is a wider set of VMR wheels and 245/40/18 RE-71R's. That combined with my tune is able to slay cars that are much faster than my 335i. If I had and LSD and more front camber it'd be another animal but as you said it'd be a ton of $$$ and some DD compromises.

[Desertnate]

Originally Posted by ClevelandBeemer

So regarding camber, there is nothing you can do other that the camber correction hubs. There is no other OE part offered for the F32 that will improve your front camber. If your F32 is xDrive then forget about adding camber. You will significantly increase your risk of snapping front drive shafts.

My car is a RWD M Sport, so I won't have any of the xDrive worries.

Are you saying with the stock hubs there is no way to dial in even a little bit of negative camber up front? I'm not looking for anything too crazy.

In terms of other parts. You actually can use slotted/dimpled rotors. They were an option offered on the F3X cars. The M-Sports catalog has a few options you can take advantage of. The M-Sport brakes and the M-Sport differential. If it were me I'd do the differential all day long as you will experience significantly more benefits than the BBK. Bigger brakes are not needed unless you are doing extend time on a race circuit link Road America or VIR.

I had no idea anything other than solid rotors were offered from an F3X, although I've not looked at the accessories catalog in a while. Even then, based on my reading of the rules, I was under the impression performance accessories were not allowed in Street Class they are upgrades installed post-purchase by the dealership/owner/shop

Either way, I've got the THP so brakes are not a worry.

My recommendation, get a 1" wider set of wheels and some Bridgestone RE-71R's. Probably the best bang for buck upgrade you can do. Not only will it make you faster but it will save you money by saving your PS4S's. You can also do the BMW hubs as well and still stay in F-Street.

I've thought about a set of wheels/tires and most everyone else in my class at our local region has gone that route, but I'm not sure I'm that committed to spending that much money at this point.

I'm seriously considering unloading the F32 for something smaller and more fun and pair it with a inexpensive daily. Of course used car prices need to become more realistic before I do anything...

I AutoX my daily driver 2013 335i M-Sport. My only suspension related mod is a wider set of VMR wheels and 245/40/18 RE-71R's. That combined with my tune is able to slay cars that are much faster than my 335i. If I had and LSD and more front camber it'd be another animal but as you said it'd be a ton of $$$ and some DD compromises.

Ultimately this is where I may end up vs. installing new hubs or anything else. In my class there is a guy in a brand new G20 M340 xDrive and another in a Caddy ATS both of whom run 200-wear tires and they are both in the top 20 of a 100+ driver field. Of course, driving ability has a lot to do with it too...


Thank for the inputs, It gives me some insight and more to think about.

[ClevelandBeemer]

Originally Posted by Desertnate

Are you saying with the stock hubs there is no way to dial in even a little bit of negative camber up front? I'm not looking for anything too crazy.

Yep there is nothing you can do other than adding a 1" wider wheel to increase your front camber(a wheel spaced further from the hub will slightly increase you effective camber rate). BMW did not build in any front camber adjustment and any other mod will take you out of F-Stock.

Originally Posted by Desertnate

I had no idea anything other than solid rotors were offered from an F3X, although I've not looked at the accessories catalog in a while. Even then, based on my reading of the rules, I was under the impression performance accessories were not allowed in Street Class they are upgrades installed post-purchase by the dealership/owner/shop

I can make the argument that because the M-Performance brakes are a factory/port installed option they would be perfectly legal.

Either way, good luck on your decision making!

[brigade24]

245mm is a good width for an 8" wide wheel. if you add those swivel bearings that add negative camber, make sure to verify if it will rub the shock with wider tires on...should be ok, but good to make sure because taking those swivel bearings out is a less than pleasant experience.

For stock class you can change one sway bar so since you're RWD, you can get a bigger front bar.

[Desertnate]

Originally Posted by brigade24

245mm is a good width for an 8" wide wheel. if you add those swivel bearings that add negative camber, make sure to verify if it will rub the shock with wider tires on...should be ok, but good to make sure because taking those swivel bearings out is a less than pleasant experience.

Thanks. I found other threads discussing the swivel bearings vs camber plates and how tire clearance varied greatly due to how they changed the suspension geometry in different ways. More to consider.

For stock class you can change one sway bar so since you're RWD, you can get a bigger front bar.

I saw that when going of the Street Class rules. Would a larger bar in the front really improve rotation and reduce understeer that much since I'm still running the factory staggered wheels?

A little off topic, but I can tell I've got a lot to learn and this is becoming quite the rabbit-hole to go down.