My E90 M3 Dedicated Track build (with pix!)

[dogbone]

Originally Posted by admranger

Ducting will extend the life of brake rotors and pads. Just have to be careful on colder days to block off some of the cooling to avoid over cooling them.

When was the last time you changed your wheel studs? They are a service item on a regular interval.

Never considered ducts because my brakes never overheat. But reducing heat for other parts could be a different consideration.

The studs were replaced two months ago. In this case, it’s not the studs. The hub failed.

[roastbeef]

i like your line through 3-4-5, i'm going to have to experiment with that a bit. i think i've had a problem with it for a long time because willow springs was my first track day and i must have watched the jack oleson guide to big willow about five times prior to going- so his porsche line was in my head.
a little more experience over the years has shown me that what works for one car/driver may not work for another.
did you do anything different in your 3-4-5 combo, or did it just execute the way you always intend to?

[aswy6]

How often does stuff break in your car when tracking? How is reliability when tracking? Or tracking plus DD?

[admranger]

Originally Posted by aswy6

How often does stuff break in your car when tracking? How is reliability when tracking? Or tracking plus DD?

Tracked my E46M3 for years w/o any failures at all. Don't go off track and you'll likely not break things. Studs/rotors/pads/fluids/tires/bushings/shocks/wheel bearings (and hubs!) are subject to wear and fatigue and should be replaced on a schedule.

[inTgr8r]

Originally Posted by dogbone

Never considered ducts because my brakes never overheat. But reducing heat for other parts could be a different consideration.

The studs were replaced two months ago. In this case, it’s not the studs. The hub failed.

Good info on a reason to NOT drill and tap hubs to accept a larger size stud.
I had already decided against the idea, this just reinforces it.

[aswy6]

Originally Posted by admranger

Tracked my E46M3 for years w/o any failures at all. Don't go off track and you'll likely not break things. Studs/rotors/pads/fluids/tires/bushings/shocks/wheel bearings (and hubs!) are subject to wear and fatigue and should be replaced on a schedule.

Thanks for info. I would like to start doing 1-2 track days per month, but my car is going to be a DD until September. Does it get stupid expensive at some point of tracking the car?

[admranger]

Originally Posted by aswy6

Thanks for info. I would like to start doing 1-2 track days per month, but my car is going to be a DD until September. Does it get stupid expensive at some point of tracking the car?

Nah, it's practically free. Try it. You won't get addicted and spend every last penny you have chasing track time. Trust me. Would I lie to you?

Yeah, it gets expensive at some point for everyone. Just depends on what your version of expensive is. At one point I had a 40' diesel pusher motorhome, a race car, and a 26' enclosed trailer. It wasn't expensive...to me. My wife on the other hand. Yeah, it was expensive. Sometimes she's so unreasonable...

[dogbone]

Originally Posted by aswy6

How often does stuff break in your car when tracking? How is reliability when tracking? Or tracking plus DD?

I give BMW a lot of credit when it comes to the E9x M3 chassis. My E90 M3 has seen a lot of punishment. It is incredibly durable in my opinion. It doesn't suffer many issues. The rod bearings and the throttle actuators seem to be the most common. I have replaced my rod bearings. I have not had the throttle actuator issue. Other than that, stuff like control arms, sub frames, engine, hoses, shock towers, electronics, and that kind of stuff have held up remarkably well. Stuff like engine mounts fail on a regular basis, but I'm really punishing those with a supercharger and tracking.....not too surprised.

Here are the phases of my car's life:

-Brand new up to 3 years old, my car saw only daily driving. No track. It was 100% reliable. Never an issue with it.

-From three years old to six years old, it saw both daily driving and track duty. It was seeing 20-25 track days per year. It was extremely reliable. The main thing that went wrong in that time was the steering pump/rack were replaced because the steering wheel would basically lock when the car was motionless. I didn't like the stock brakes on track. I replaced those right away. The other mods were done as performance upgrades.

-From 6 years to present day 9 years old, the car has been ONLY track and is towed to the track. It has continued to be very very reliable. No major OEM system of the car has gone down. And the car now has over 130 track days on it.

I can easily chalk up this recent issue of the hub to an off-track experience one month ago in Turn 9 at Willow Springs. While I have been off track many times in general without issue, this time was higher speed and more sideways. When you go off-track, all bets are off when it comes to knowing what forces were applied to the car.

[dogbone]

Originally Posted by aswy6

Does it get stupid expensive at some point of tracking the car?

It all depends on how fast you want the car to be. If you're satisfied with the performance and setup from the factory, then costs can largely be contained to dealing with the consumables.

However, if you want the car to be a top performer, then there is literally no limit on how much money you can spend.

If cost is the most important consideration, there's a thread in this sub-forum called the Budget-Minded Track Build. There are good conversations in there.

[roastbeef]

Originally Posted by aswy6

Thanks for info. I would like to start doing 1-2 track days per month, but my car is going to be a DD until September. Does it get stupid expensive at some point of tracking the car?

yes and no.

if you can track the car as-is and have discipline in not modding the car, it doesn't get out of control.

however, maintenance intervals come up quicker. brake pads, brake rotors, brake fluid, tires, and other fluid intervals all have accelerated wear.

it gets stupid expensive when you use $500 racing pads that last about four days, and a set of $800 tires lasts three days. on top of ~$300 entry fees, $200 for insurance (optional), $200 in fuel, you could be spending around $1,100 a weekend in combined costs when factoring in consumables.

just be conscious that you're treading on a slipper slope. this sport is addicting and the camaraderie just adds to the fun.

[kyippee]

Originally Posted by dogbone

I would like to get up to Sonoma and Thunderhill with slicks. Haven't gone to either of those places with slicks yet. I think I could drop a decent amount of time at both of those places with decent tires and weather and a bit more practice.

There's Sonoma Speed SF May 26th (Saturday) that I'm eyeing....

[dogbone]

Originally Posted by roastbeef

i like your line through 3-4-5, i'm going to have to experiment with that a bit.

a little more experience over the years has shown me that what works for one car/driver may not work for another.
did you do anything different in your 3-4-5 combo, or did it just execute the way you always intend to?

I changed my approach.

In general, I aim for the shortest way around a track as possible. This is the approach I used to take at Turn 3/4/5. I would stay mid-track/fairly tight at the top of Turn 4 to try to avoid wasting track length. My old way of thinking was that I'm not really going THAT fast at the top of Turn 4, so why not turn early and hug closer to the inside of that curve. The idea was not necessarily terrible, but what it didn't account for was that at the end of Turn 4, when you want to really get on throttle, there is very little grip due to the track heading down a hill.

Turn 4 presents some interesting challenges because there's very little grip there at the exit. Somehow---and I know this is weird-----if you are turning the steering wheel a lot---which you would be doing if you hug the inside, you understeer.....and then a moment later, the ass is stepping out on you and you're counter steering. All that nonsense is a big time waster and it prevents you from getting 100% on throttle again.

It turns out, it is more efficient to run to within a few feet of the top edge of Turn 4, tap the brakes if you have a lot of speed and then turn down the hill to the exit of Turn 4 from the top where there is some grip. The big advantage this method gives you is that, by going further to the top of Turn 4 and turning up there, you're doing most of your turning up there and you don't have to turn the steering wheel AS MUCH at the EXIT of Turn 4 when the pavement is falling away, and this allows you to avoid the understeer and oversteer moments by turning the steering wheel less. This allows you to get back to the gas pedal more consistently and you can concentrate more on charging down the hill towards Turn 5. Again, getting kicked out wide on the exit of Turn 4 is not fast. It forces you to wait to get on the gas as you go down the hill. You want to go down the hill as straight as possible, not get kicked out, so you can get as much acceleration in as possible before the braking zone of Turn 5.

In this chart, you can see different lines through Turn 4. The Dark Blue (1:26.0) and Grass Green (1:27.0) lines were from my latest track day there. The Green line was the previous lap to the 1:26 lap. All the other lines are from 1:27.x laps from previous days. You can see in Turn 4 at the top, the Blue and Green lines go wider than previous laps. At the exit of Turn 4, you can see both of those lines don't get kicked out as far as the older lines that tried to keep it tight through Turn 4. I am heading more straight down the hill which allows me to get back to the gas faster. The Orange line, which was my previous best from 2016, was really tight at the top of Turn 4 and I got kicked out to the far edge of the track. The Grass Green line took it the farthest out to the edge at the top, and I learned on that lap that I didn't have to go that far out. So the Dark Blue doesn't go out as far. But I still was able to head straight down the hill.



And it's worth showing that I picked up a nice little chunk of time on that fast lap when I felt like I finally got Turns 3/4/5 much better. In the two pics below, I have the cursor set at two different spots so you can see the time gains from Turn 3 to the apex of Turn 5.

You can look at the map and see where the cursor is on the track. The red lines in the low chart represent the time delta of 5 laps compared to the fast lap. And you can see the time delta in the bottom right corner.

In the bottom chart, you can see all the red lines rise from 5000 feet to 6300 feet. Those lines going upwards means they are losing time to my fast lap. And they all go up. By looking at the two charts you can see how much time was lost to my new fast lap. The time gain ranges from .3 sec to .6 sec. That's a pretty solid time gain from just approaching the turn differently!

Beginning the climb of Turn 3:


Entering Turn 5:

[roastbeef]

makes a lot of sense, thanks for the detailed analysis. i'm not very familiar with the charts and such, but i think i'm understanding it and interpreting it correctly.

another thing i need to improve on is braking discipline at the bottom of 5... it is easy to pick up a lot of speed fast going down the hill, and the transition at the bottom can be difficult if the braking isn't executed correctly and you load up and overtax the front wheels while trying to change direction if it gets screwed up.

[M3Ap1]

You have an awesome build.
Do you mind sharing you alignment specs?

[SYT_Shadow]

Originally Posted by inTgr8r

Good info on a reason to NOT drill and tap hubs to accept a larger size stud.
I had already decided against the idea, this just reinforces it.

I've been thinking of this long and hard... especially after my car spent a week at Rogue Engineering

In the end, the BW Race ones don't break frequently and I don't like the idea of weakening components by putting fatter studs. I do loooove the idea of the fatter stud but not at the price of a weaker hub.
Also, the wheel nuts are still 17mm so now they are quite thin!

[admranger]

dogbone Really nice analysis of Turn 4. Thanks!

Do you have a visual reference for how far up to go? There used to be a distinct line in the pavement but I haven't been to WSIR since the repaving took place.

Truth be told Turn 4 was my nemesis at WSIR. I'd lose a butt-ton of time up there, usually from not going high enough and struggling with the understeer/oversteer issue you described.

And don't be too hard on yourself for going off in turn 9. I've lost count... Best was going off due to a too early apex and exiting into pit lane instead of trying to save it. Qualifying lap iirc. oops. Never, ever try to be a hero if you're going to go off on the outside. Bad things happen. Willow Springs is also where I broke studs. I think mine just aged out, but the LF takes an ass kicking for a long time there.

Best memory of Turn 9 is going side by side w/Ralph Warren when he had the E36M3 (I was on the inside) and holding the position for the pass (Ralph's tires had died). Both cars were slipping and sliding around through the turn. Good times.

[dogbone]

Originally Posted by admranger

Do you have a visual reference for how far up to go? There used to be a distinct line in the pavement but I haven't been to WSIR since the repaving took place.

I don't have a visual reference....the reason is that I only drove two sessions so I didn't get many laps to really iron things out.....but you can watch the video. It gives an idea of what it looks like. I proved to myself that it is not necessary to ALL the way to the top edge. You could say like 75% up to the edge is in the neighborhood of where you went to be. And then it takes a bit to sort out how much you need to brake. Since I'm supercharged, I can carry quite a bit of speed up the hill. You want to stay on gas as long as possible, dab the brake, turn, and then get back to gas to as quickly as possible so you can hammer down the hill.

Yeah, lots of people have interesting stories about Big Willow....hehe

[admranger]

Originally Posted by dogbone

I don't have a visual reference....the reason is that I only drove two sessions so I didn't get many laps to really iron things out.....but you can watch the video. It gives an idea of what it looks like. I proved to myself that it is not necessary to ALL the way to the top edge. You could say like 75% up to the edge is in the neighborhood of where you went to be. And then it takes a bit to sort out how much you need to brake. Since I'm supercharged, I can carry quite a bit of speed up the hill. You want to stay on gas as long as possible, dab the brake, turn, and then get back to gas to as quickly as possible so you can hammer down the hill.

Yeah, lots of people have interesting stories about Big Willow....hehe

I think we used to teach 2/3rds to 3/4's of the way up. I had a tad less hp than you being in either a stock E36M3 or an E36M3 w/a 2.8 liter, M3 cams, bigger injectors, etc. in prepared class. So 1/3rd your hp...

[roastbeef]

dog, do you purposefully run any rake in your suspension setup? have you fooled around with specifically rake in your suspension setup?

[dogbone]

Originally Posted by roastbeef

dog, do you purposefully run any rake in your suspension setup? have you fooled around with specifically rake in your suspension setup?

I have not approached rake with any particular science. Over the years, the shops I work with have aimed to lower both ends of the car to be the lowest it can realistically go with the size tires I'm jamming under there.

The car does have some rake, but it's not a lot.

I cannot go lower in the rear because I've already touched the fuel filler tube. So, there's no going lower in the rear. Plus I run big aero which pushes down on the rear quite solidly at speed. If I desired to flatten the rake out, the front would have to come up. I'm not super excited about that because it allows more air under the car if I don't lower the splitter. I guess we could look into ways to lower the front splitter, but to be honest, the car feels quite good these days as far as handling goes. It's quite responsive.

We have touched on this topic on page 20 of this thread: Richbot posted a pic of an M3 race car with virtually no rake.

http://www.m3post.com/forums/showthr...158445&page=20

[dogbone]

(In 2016, in another sub-forum, I wrote the following post that deals with the topic of MDM-and-which-brake-calipers-are-used. On a fairly regular basis, I seem to need to refer to it, and I always have to search to find where I posted it. So——I’m posting this info in my build thread, so that when the topic of MDM-and-which-brake-calipers-are-used comes up, I know where to find it. If you care at all about MDM, it's something worth checking out)

Many people incorrectly assume that MDM primarily uses the rear brakes. The fact is, MDM/DSC/Traction Control on the E9x M3 uses the front brakes the vast majority of the time.

The AIM Solo DL can track individual brake caliper activations. By comparing when you physically press the brake pedal and when the calipers are being activated, you can see where MDM steps in with the brakes, and what it does to control the situation. In my experience, 99% of MDM braking is done with the front brakes.

Using screen captures from the AIM software, we can look at MDM activity from 5 different tracks around California. Each picture is from my fastest Euro MDM-on lap at each track. I would say I wasn't making any "mistakes" but MDM was lightly stepping in to just make sure the situation was under control.

How to read the info in the pics: Each pic has five graphs lines.

-Graph 1 at the top: my actual brake pedal press
-Graph 2: Front left caliper activation
-Graph 3: Front right caliper activation
-Graph 4: Rear Left caliper activation
-Graph 5: Rear Right caliper activation

We can see where MDM is doing it's thing by looking in the blank spaces where I'm NOT pressing the brake pedal, but the computer is activating the calipers. In virtually every case at all 5 tracks, the rear brakes are basically never activated by the MDM system.

In this first chart at Buttonwillow, we can see that at 750 ft, the Front Right caliper activates on it's own. Between 6500-7500 ft, you can see the Front Left caliper is active for a whole 1000 ft as you go around Riverside which is a big rounder. The caliper activations are not huge....they're usually just nudges.

And then, you can compare that to the 6th chart at the bottom where I show my 1:49 lap at Buttonwillow with DSC-off. You can see it's totally quiet in between brake presses on all calipers.

The Big Willow chart is interesting. MDM is activating the Front Left caliper for very long stretches---1500 ft in Turn 2 and 2500 ft (!!) in Turn 8/9. It wants to make sure the rear of the car stays in the rear, so it's encouraging more of an understeer situation where it's sensing oversteer might be imminent. If you're in a rounder going to the right and the front left caliper activates, it's encouraging the front to understeer which helps keep the rear behind you. At the same time, MDM is probably holding back the rpms if you're pressing hard on the gas because it doesn't want to add more speed to the situation.

Again, the caliper activations are fairly mild, but I'd say that 2500 ft of that at 130 mph is still building some serious heat.

So, at a wide variety of tracks, it seems that DSC uses the front brakes in most cases.

Since we're on the topic, the other thing that is sort of interesting to see is how the braking system activates the calipers when you press the brake pedal. If you look at the activation profiles of the fronts, they are usually different. At Big Willow, the computer is definitely working hard trying to figure the best way to activate those calipers and keep the car going in a straight line on what is a poorly paved track. The first brake press and the press at 6000 ft are quite different between the two front calipers. At Laguna Seca, where the pavement is much better, you can see the brakes activate much more uniformly. Anyway, I find it interesting that we can see how the braking system is making [very quick] decisions to keep things under control regardless of whether DSC is on or off.

Buttonwillow: 1:51 MDM-on



Big Willow: 1:27 MDM-on



Chuckwalla: 1:55 MDM-on



Laguna Seca: 1:39 MDM-on



Sonoma: 1:51 MDM-on



Buttonwillow: 1:49 DSC-off

[SYT_Shadow]

As always, super interesting info Mr Bone!