My E90 M3 Dedicated Track build (with pix!)

[admranger]

Interesting graph on the LF caliper at Big Willow. You can see going into 9 it hates you. Also a little into 2 (both are right hand turns for those that don't know). 9 is bumpy as hell (not as bad as 8, especially if you hug the inside of 8, ugh!). I'm trying to figure out why it's activating in these two spots.

I do like (most) of your brake inputs. Nice, nearly vertical application that trails off as you release. Looks excellent!

[dogbone]

Originally Posted by admranger

Interesting graph on the LF caliper at Big Willow. You can see going into 9 it hates you. Also a little into 2 (both are right hand turns for those that don't know). 9 is bumpy as hell (not as bad as 8, especially if you hug the inside of 8, ugh!). I'm trying to figure out why it's activating in these two spots.

I do like (most) of your brake inputs. Nice, nearly vertical application that trails off as you release. Looks excellent!

MDM is intervening in Turns 2 and 8/9 because it's trying to ensure that the rear will not step out. These two spots are long, fast rounders to the right---a perfect opportunity for the rear to come out to the left if you're aggressive with the throttle while holding the steering wheel closed in the turn. The tail could come out and you'd have a high speed oversteer situation.

MDM is doing two things simultaneously to prevent an "out of control" situation.

1. MDM is trying to preemptively deal with a potential oversteer by activating the Front Driver-side caliper in small amounts repeatedly. By grabbing that caliper, the front will gently "pull" to the left. You won't really notice the direction change, but it's enough to keep the tail of the car in check. This is encouraging more of a slight understeer situation in this moment. With the front tending to the left, that discourages the tail from swinging out to the left.

2. At the same time, MDM is holding back the engine's full power. This also helps to prevent you from power-oversteering the car. You could jam your foot all the way to the floor in Turn 2 with MDM on and it would ignore that input and only give you an amount of power that it feels is appropriate.


Regarding the look of my braking profiles, those charts are from 2014-to-early-2016. I have worked quite a bit to improve my braking behavior since then---later, harder, fully committing to the brake press and trying to release smoothly. I'll try to put some AIM charts together soon to show older braking behavior to current behavior.

[admranger]

Originally Posted by dogbone

MDM is intervening in Turns 2 and 8/9 because it's trying to ensure that the rear will not step out. These two spots are long, fast rounders to the right---a perfect opportunity for the rear to come out to the left if you're aggressive with the throttle while holding the steering wheel closed in the turn. The tail could come out and you'd have a high speed oversteer situation.

MDM is doing two things simultaneously to prevent an "out of control" situation.

1. MDM is trying to preemptively deal with a potential oversteer by activating the Front Driver-side caliper in small amounts repeatedly. By grabbing that caliper, the front will gently "pull" to the left. You won't really notice the direction change, but it's enough to keep the tail of the car in check. This is encouraging more of a slight understeer situation in this moment. With the front tending to the left, that discourages the tail from swinging out to the left.

2. At the same time, MDM is holding back the engine's full power. This also helps to prevent you from power-oversteering the car. You could jam your foot all the way to the floor in Turn 2 with MDM on and it would ignore that input and only give you an amount of power that it feels is appropriate.


Regarding the look of my braking profiles, those charts are from 2014-to-early-2016. I have worked quite a bit to improve my braking behavior since then---later, harder, fully committing to the brake press and trying to release smoothly. I'll try to put some AIM charts together soon to show older braking behavior to current behavior.

I was having trouble wrapping my head around the weight transfer aspect of the braking, but your explanation (the throttle bit I didn't think about) makes sense. Lightening the rear up to keep it in line didn't make sense, but the turning aspect of braking the LF slightly would make the front want to move left (ever so slightly).

[dogbone]

Originally Posted by admranger

I was having trouble wrapping my head around the weight transfer aspect of the braking, but your explanation (the throttle bit I didn't think about) makes sense. Lightening the rear up to keep it in line didn't make sense, but the turning aspect of braking the LF slightly would make the front want to move left (ever so slightly).

Yup. In essence, when the computer slows one corner of the car by activating a single caliper, it is creating a point of rotation---in this case, the front-driver-side caliper activating would encourage a counter-clockwise rotation of the entire car around that wheel. By doing that, you counteract a potential clockwise oversteer, which is what you'd be facing in Turns 2 and 8/9.

[dogbone]

Let's file this one under---Wow, that doesn't look fun at all....

I decided after my cracked hub adventure that I wanted to replace all 4 hubs, install new studs, new lug nuts, replace the front driver rotor hat because I'm worried it saw some pretty strange forces it doesn't usually see. There were some weird gouge markings around the hat's hub hole.....didn't like that. (And I changed out one other thing that I'll talk about in the next post.)

The car is 9 years old. It's been on track 6+ years. I've replaced the front hubs several times, but the rears were original to the car.

I find it amazing how different the swapping process is between the front hubs and the rear hubs. The fronts I can do myself. I did it at the track. Fairly easy. The toughest part is reaching the bolt heads to tighten them properly.

The rears? Wow. The rears are something completely different. They disconnected every damn thing and pulled the uprights off the car. Then the process of getting that bearing out of the upright is no joke. The rear hub bearing is a beefy item and it is pressed into that upright real good. My hat is off to the guys at Minicorsa for diving in head first on this task. That was tough work.

So, it was a big round of preemptive maintenance this week---replacing some stuff before it goes bad. It took many hours. We also did an alignment since it's been awhile, and since so much stuff was disconnected. I'm glad we aligned it because the rear passenger side was way off. Whether it was from driving or from all the disconnected stuff is hard to know.

I am planning on replacing the front hubs once per year now. The car has so much grip, aero, power, brakes......replacing the hubs is a small price to pay for having all those things. I chatted with a high-end endurance race shop, and they just use regular hubs, and replace them regularly.

btw the way, thanks to the Bimmerworld stud kit, I have a new and better way to double-nut studs onto the hubs. In the past, I didn't buy the whole kit of studs and nuts from Bimmerowrld, I only bought studs. And I used old lug nuts for double-nutting which is not ideal because the noses/threads get trashed so you can't use the same lug nuts for very many installs.....If you buy the full kit of studs and nuts, they include two M12x1.5 hex nuts to use for double-nutting. So much better! Just two of those hex nuts were able to install all 20 studs. M12x1.5 is a bit tough to find in regular local hardware stores, but I recommend getting some. And I believe the hex nuts are 19mm, so you need to pre-plan for that too for the installation.

Anyway, the car is all back together and ready to go. I'm planning on Buttonwillow with Speed District on May 25 and then Speed Ventures Bimmerfest/Bimmer Challenge at ACS on the 26th.

[SYT_Shadow]

I'm glad the car is all sorted out. I've also heard that the rear hubs are a massive PITA in the E46 and E9X generation!

Those install nuts in the BW kit are key!

Good luck at Bimmer Challenge!

[leo95se]

some conjecture on studs - I am not choosing or bashing, only offering anecdotal evidence from what I have witnessed. I have had Turner studs on my car for 7 years, without issue. I proactively replace them (2-3 years?). I have never seen a failure (knock on wood!). I have friends who have had BW race and track/street studs, both failing. most recently, within 1-2 track events. and I mean a few studs, not a one off thing. something to consider. now, its possible they are even made in the same factory, but I will keep my loyalty with Turner, for this particular part.

[Richbot]

Front hubs - easy <1hour DIY per side with a floor jack

Rear bearings - hail no I pay someone.

[dogbone]

Originally Posted by SYT_Shadow

I'm glad the car is all sorted out. I've also heard that the rear hubs are a massive PITA in the E46 and E9X generation!

Those install nuts in the BW kit are key!

Good luck at Bimmer Challenge!

Thanks!

Yeah, I feel silly for not thinking about just using regular hex nuts versus lug nuts....you know how someone at some point just tells you to do it a certain way, and you do it like that and don't really question it?.....that's how it was. Along the way, someone simply said, "just use two lug nuts", so I did and never thought about it much. And then I see those two little hex nuts in the picture of the Bimmerworld full kit and I'm like, damn I'm an idiot....haha!

[dogbone]

Originally Posted by leo95se

some conjecture on studs - I am not choosing or bashing, only offering anecdotal evidence from what I have witnessed. I have had Turner studs on my car for 7 years, without issue. I proactively replace them (2-3 years?). I have never seen a failure (knock on wood!). I have friends who have had BW race and track/street studs, both failing. most recently, within 1-2 track events. and I mean a few studs, not a one off thing. something to consider. now, its possible they are even made in the same factory, but I will keep my loyalty with Turner, for this particular part.

I totally understand staying with something that works when it comes to wheel studs. After I broke a number of studs, I decided to buy a bunch of different brands so I could see them in person. I bought the Turner ones. They looked fine but I didn't install them. Sold them to a friend who had good luck with them.

The breakages I was suffering a few years ago were all the same. They were breaking inside the hub. The Bimmerworld stud had a collar that sits flat against the hub flange. I really liked that design. Most other studs rely on creating tension by just running dead-end into the hub threads. The Bimmerworld stud looked like it could distribute the force a bit more evenly on the flange with that collar. At least that would be the hope. It worked for me.

In this recent case, the hub definitely failed. I give the studs credit for holding on as well as they did.

Anyway, every person you talk to has a different experience with wheel studs. Glad you found something that works.

[dogbone]

Originally Posted by Richbot

Front hubs - easy <1hour DIY per side with a floor jack

Rear bearings - hail no I pay someone.

haha! Boy do I agree with that statement.

Removing that damn rear bearing is nasty. And the axle nut needs to be torqued to 221 ft lbs. And the nut needs to be hammered to crush the edge into that notch......and the whole bottom of the car is torn apart, and your alignment is hosed, and who knows what else......Geezus! Couldn't BMW make that just a LITTLE friendlier?!!!

[leo95se]

Originally Posted by dogbone

The Bimmerworld stud had a collar that sits flat against the hub flange. I

so does the turner stud. it locks at that transition point -
https://www.turnermotorsport.com/p-3...6-e9x/?pdk=AAw

[dogbone]

In my previous post, I mentioned that there was one other change done to the car this week.

Since early 2017, I've been wondering what to do about my wheel setups. I have been driving three sets of 10.5" square Apex ARC-8's. Overall, I have had good luck with my Apex rims. And they're still running fine. And I like the guys at Apex. They have always been nice to me. Occasionally, a rim will bend and not be able to balanced so I would replace it. And Apex has a friendly replacement policy to the original purchaser. But as my grip has continued to go up and my lap times have continued to improve, I have wondered if I should be driving on a wheel with a higher spec---stronger, stiffer, etc. The hub incident was the final push that made me decide to push the Go button on refreshing everything in the rotating package---hubs, studs, and now wheels. (Brakes/rotors were already new.)

Here are the things I was hoping for if I were to switch to a new wheel:

-Stronger: It would be nice if I could reduce or eliminate bends. (I never cracked an Apex wheel.)
-Stiffer: Aside from reducing bends, a stiffer rim would provide a more consistent feel, and I have had some conversations with some knowledgable people who believe a stiffer rim could resist stud breakage better because it would not deform as much under high loads. I was very interested in that.
-Lighter: Reducing rotating mass is always beneficial, but was not my primary consideration.
-Different offset from my current ET27: I have desired to try something in the ET 22-25 range on 10.5".
-Reasonable cost: I wanted to be able to afford to replace all three sets at the same time if possible.
-Warranty policy: It would be nice if the company would give some warranty consideration with track use. There are plenty of forged wheel options out there, but in most cases, they don't provide any warranty help for damage done on track.
-Different looks: I figured a change in styling and color could be cool. I'm not trying to be a style hound, but a new look wouldn't be a bad thing.

That's not a demanding list, is it? Actually, I didn't really find much that could satisfy all those wishes. The warranty really was the biggest hang up. No one wants to warranty track stuff. Anyway, I wasn't in a hurry so I just sorta waited.

Then last summer, I was chatting with Steve at EAS, and he mentioned there was a new forged rim coming to market soon that might be worth a look. He said the company was new, but the founder had worked in the wheel industry for a long time. It was called Titan 7. I looked into them a bit, and thought the wheels were attractive, but they weren't shipping yet, so I didn't put much effort into it.

Then in January, I was at Chuckwalla doing a Bimmer Challenge, and Titan 7 had a booth. So, I wandered over to say hi and ask a few questions. Eddie Lee, who is the founder, was in the booth and we ended up chatting for 45 minutes. He's a very nice guy who has a lot of industry experience and he patiently answered all my dumb questions. After that conversation, I was interested in the wheels. The T-R10 seemed to meet all the criteria in my list:

-They are claimed to be very strong due to a 10,000 ton press being used to shape the aluminum.
-This 10,000 ton pressing process also results in the rims being quite stiff and resistant to deflection under high-G loads.
-They are lighter than the ARC-8's. ARC-8 - 20.5 lbs versus T-R10 - 19.5 lbs (The T-S5 style is 18.8 lbs.)
-The offset is ET 25.
-MSRP is $1920 for a 10.5" square set.
-The wheel has a limited lifetime warranty to the original purchaser, and Titan 7 does give warranty consideration to wheels that see track use. What they don't warranty is if the wheel has an obvious direct impact from something like a crash or has been jammed into a curb. But if the wheel has some structural issue that is a result of use on track, they are willing to stand behind the product.
-The T-R10 is a 10-radial spoke wheel. And I was considering black, so the look would be quite different than my current silver ARC-8 wheels.

So, after a long consideration process, I decided to jump in with both feet. I've replaced all 3 sets of Apex with Titan 7 T-R10's. I worked with EAS for the purchase. They always make things easy. And now I have all 12 rims in-hand. My front porch looked ridiculous. I looked like a distributor......haha!

A few pix:










Other notes of interest for me:

-Eddie had a 20 year run with Mackin Industries. (Mackin imports Rays Engineering, Yokohama wheels, etc.) While he was there, he developed wheel programs for BMW factory race cars and other pro teams which is a pretty demanding world. He's worked on creating private labels. He's been on-site at many production plants in Asia. Basically, he has dealt with wheels his whole career. In fact, his journey in his business reminds me of my journey in my music business. We both worked for other corporations for a long time, gained a bunch of knowledge from all the time in the trenches, and we both figured out how to build a small business around the knowledge we gained over the years. When someone comes up through the ranks like that, they have seen a business from all sides. That's how it worked for me, and Titan 7 seems to be the result of similar experiences. That's appealing to me.

-I asked about production. Due to the small size of the company, I was worried that maybe T7 was piggybacking off some other larger production runs and just slapping their logo on something. Nope. The answer was interesting. He made a relationship with an industrial manufacturer that had not been making consumer products but wanted to. They had some impressive machinery like 10,000 ton presses. He has setup all the business logistics with this manufacturer from scratch. This is not a generic run-of-the-mill piggyback wheel that's the same as everyone else with a different logo slapped on it.

-Regarding the 10,000 ton press and general forging - My knowledge on forged rims was lacking. So, I asked a bunch of questions. I don't want to dwell on what a forged rim is because there's lots of great info out there, but I'll touch on a couple things. Forged wheels are desirable because you start with a solid cylinder of aluminum, heat it up and then you press it into an initial shape with powerful presses. The more pressure you use when you press it, the denser/stronger the rim material gets. (They say the "grain structure" of the metal is improved.) According to Eddie, most forged rims are made with 6,000 and 8,000 ton presses. 10,000 ton presses are more rare. (He said only one other wheel maker is using a 10,000 ton press.) And with a forged rim, there's no potential for microscopic porosity, which is air trapped in the metal. Cast wheels start as molten aluminum and the molten metal is poured into a shape. When you start with a liquid and pour it into a shape, the possibility of getting air trapped in the metal exists, which is not ideal for overall strength. And you don't get the benefit of the pressure from the press. (You compensate by putting more metal into the wheel, i.e. the wheel is heavier.) Flow Formed wheels (like Apex) which use spinning during the casting process produce better results. But the strength and stiffness per pound just isn't the same as a forged wheel. So, porosity is just not an issue with forged rims, and having a denser and more consistent rim material allows you to make a light wheel because you can use less material, but it's still very strong and stiff. Ok, enough about forging....I'm not the expert on this topic.

-Between the two wheels offered by Titan 7, there is a weight difference. In the 10.5" size: T-S5 18.8 lbs vs. T-R10 19.5 lbs. I asked Eddie about this. He said both wheels are built to be very strong. But they decided to beef up the T-R10 a bit more. According to him, the T-R10 is the stronger of the two. And I guess that's not really a surprise. It is 10 spokes coming straight off the hub, versus the T-S5 with 5 spokes, and the T-R10 is heavier so there's more material to work with. He was very clear that both were built like "tanks", but that the T-R10 was a bit of a beefier tank. For me, looks was bottom of the list on importance. The TS-5 is a sexy wheel, but I was totally fine with the radial look of the T-R10. And while weight is a consideration, strength was much more important, so if the T-R10 is stronger due to the additional 0.7 lbs, I'm fine with that. It's still a full pound lighter per wheel than the what I had.

-I like the ET25 offset. On Apex, I had ET27 with a 3mm spacer. Now, after test-fitting, I've seen I can run most tracks without a spacer. The clearance to the spring perch is totally fine. The other consideration I have to deal with is my supercharger intake. Buttonwillow's Off-Ramp corner is brutal when you have tight tolerances. The corner is very tight, slow, and uphill......it's just nasty. The tire just jams up into that wheel-well with the steering wheel turned hard. I may run the spacer at Buttonwillow to help preserve the intake and now I'll be even further away. And I appear to have the room on the outside. So, yeah the ET25 offset is nice for my purposes.

-Along the way, I've learned new terms such as "camber stiffness" which has to do with how a wheel deals with deflection and deformation under high G's. He claims that the T7 wheels resist high-G loads extremely well. This makes for a more consistent driving experience.

-Their wheels have been run in 24 hour races and were fine.

-Knurled bead - I was happy to see that feature. It's a nice touch to try to reduce tires creeping around the rim (yes Hoosier I'm talking to you!).

-The wheels come with wheel stems. Cool. No one told me. I bought stems for the new wheels, and now I...uhh....have extra stems. hehe

So, with the wheel change complete, I have refreshed the entire rotating package of the car---wheels, hubs, studs, lug bolts, the Essex brakes/hats/rotors are very new (8 days on the fronts, 3 days on the rear), so I'm hoping that the car is good-to-go for awhile. I am quite eager to go out and see what everything feels like! And I'm quite happy with how the wheels look!----even though I said it wasn't high on my list.....

PS. It's important for me to reiterate that I didn't leave the Apex brand due to any specific unhappiness. I just finally made a decision that I should drive a higher spec wheel because the car is experiencing very high forces now (as the cracked hub so wonderfully illustrated). I would happily recommend Apex wheels to anyone looking for Flow Formed wheels. They are a very nice company to deal with. (I have a square set of 9.5" ARC-8's that I'm keeping for my E92 M3 street car, you know, just in case I take that baby to the track!)

[///Mobbin]

Great Friday afternoon read, congrats on the new setup dogbone!

[tom @ eas]

Awesome post! Looking forward to hearing your longtime review down the road!

[surewin]

Originally Posted by dogbone

A few pix:

Thanks for the extensive background of the Titan7 company. I was already impressed already knowing they used 10,000 ton presses, but all the other info is good to know! Wheels look great btw!

[admranger]

Pretty wheels. Good thought process on replacing the parts you replaced.

[roastbeef]

this racecar porn is so hawt.

so..... are you doing to be selling some arc8's for cheap or what?

[admranger]

Originally Posted by roastbeef

this racecar porn is so hawt.

so..... are you doing to be selling some arc8's for cheap or what?

LOL, I wondered who'd be the first to ask.

[roastbeef]

vultures! lol

[BOOF-M3]

Get in line boys, I already got first dibs on a set of signed Dogbone rims.
DreamTime went with the T-S5's. She just broke them in at WGI. I am curious what her reviews are after one weekend of use.

[DreamTime]

Aww, I really don’t have much that’s worthwhile to contribute at this point My observations would likely be rather pedestrian in comparison to what other members of this conversation would have to say. I look up to all you guys on here so much and I aspire to one day be on your level. But, I have a long way to go and a lot to learn. I do absolutely love the wheels though, so far so good. Quite happy with the purchase.