My E90 M3 Dedicated Track build (with pix!)

[DRLane]

Originally Posted by dogbone

Let's file this one under: Gurney flaps-----why not!?

During the Zebulon splitter install, Ryan took a moment to check out the fender vents that had been cut. I always laugh them off as Viper ACR style-additions to the car. But he took them seriously and suggested that if I wanted to make them more effective, I should add a gurney flap to the leading edge of the hole. Basically, the gurney flap would create a bit of a vacuum behind it which would facilitate pulling more air out of the wheel well. This could be useful with the diffuser tunnels guiding more air into the wheel well.

He gave me a couple suggestions on the shapes and sizes. I decided to try a 1" flap that sits back at an angle.

Today, I cut the aluminum pieces out of 90º edging. I opened the angle out to around 125º. Painted them matte black and taped them to the car with 3M double sided tape. They're on there QUITE solidly. I was worried that I was taping them to the clear bra, but it's darn solid. I was considering riveting them but I decided I didn't want to drill more holes in the fender at the moment, and I was mildly concerned that the bottom parts of the rivets would stick down towards the tires. And I didn't want to rivet upwards and have to grind the rivet on the top side......I don't know. I taped it.

Of course, this is a small change and I won't notice it while driving, but-----might as well do it given everything else going on with aero! Gives the fender holes a bit more purpose. I gotta tell ya, in the paddock those fender holes get so many comments----quite a lot of them critical....for whatever reason, they just offend people......hehe Perhaps now people will accept them a bit more as being useful? Who knows....anyway, it's done.

Hopefully I'll have more to report on soon.

Put stickers on each side that say "wishing well, quarters preferred" with a little black net lining to collect your $$$.

[admranger]

roastbeef will want to drill holes in your Gurney flaps to save weight.

[roastbeef]

Originally Posted by admranger

roastbeef will want to drill holes in your Gurney flaps to save weight.

I wonder if 1/2 circles in a gurney flap would created vortices...

[redpriest]

Originally Posted by dogbone

Let's file this one under: Gurney flaps-----why not!?

...

Of course, this is a small change and I won't notice it while driving, but-----might as well do it given everything else going on with aero! Gives the fender holes a bit more purpose. I gotta tell ya, in the paddock those fender holes get so many comments----quite a lot of them critical....for whatever reason, they just offend people......hehe Perhaps now people will accept them a bit more as being useful? Who knows....anyway, it's done.

If anything, you can tell people it's solely responsible for your flying lap times, haha.

[redpriest]

Originally Posted by dogbone

Bad news: I think my AIM is acting funky on my CAN bus again.....You may have noticed that my video had bare bones GPS-only data on it. That's because the car acted funny mid-session and I disconnected the cable while driving. As soon as I disconnected the cable, the car started acting normally again......I will be calling AIM on Monday....

I caught the funkiness on video----short hesitations that are easy to hear from the microphone while I'm holding steady on the gas pedal. At :11 is the first hesitation, then at :16 there are several hesitations and then at :28, after I pass the Corvette the next gear change is funky. Then at :32, you see the CAN bus data like RPMs go dead because I disconnected the cable. As soon as I disconnected the cable, the car was good again......I love having my CAN data, but not at the expense of the car's performance......

Did you ever resolve this? Do you think it's related to some of the ECU settings you can configure (Enable the CAN Bus 120 ohm resistor, Silent on CAN bus)?

[roastbeef]

On the subject of fender vents. There was a podcast I listened to a while back and they touched on fender vents. The theory of fender aero is it helps, but it's not the best part. A large part of the reason they were implemented was to help keep cars on the ground should they spin at speed. It reduces lift of a sideways car.
The air is so dirty inside of a wheel well, the flow is a mess, and exit out of the fenders isn't a huge deal, but they run it because they have to in certain classes. The race engineer also went on to say he would rather close up the fenders and seal them up as best he could.

[b4hand]

Originally Posted by roastbeef

On the subject of fender vents. There was a podcast I listened to a while back and they touched on fender vents. The theory of fender aero is it helps, but it's not the best part. A large part of the reason they were implemented was to help keep cars on the ground should they spin at speed. It reduces lift of a sideways car.
The air is so dirty inside of a wheel well, the flow is a mess, and exit out of the fenders isn't a huge deal, but they run it because they have to in certain classes. The race engineer also went on to say he would rather close up the fenders and seal them up as best he could.

Meh, I've heard the exact opposite. Literally every high-performing prototype has fender vents. Seeing wind tunnel tests that show the benefit is even more proof.

[roastbeef]

I don't have any experience, nor do I claim to be an authority on the subject.
If they are required on a prototype, you can bet they are going to make them functional and advantageous.

[dogbone]

Originally Posted by redpriest

Did you ever resolve this? Do you think it's related to some of the ECU settings you can configure (Enable the CAN Bus 120 ohm resistor, Silent on CAN bus)?

I have borrowed my friends AIM Solo 2 DL and will try to see if it acts any different. More to come on this topic as I get out there.

[dogbone]

Let's file this one under: What a tease!!

I went to High Plains Raceway today to drive the splitter for the first time. The weather was very cool. There wasn't any wind. I was the only one there. Everything was set for a day of solid testing.

Get out on track, slowly warm the car up in the 39ºF temps, run three hot laps, and then on the fourth lap, fluid spews onto my windshield. I drive a bit further and then white smoke appears. Since I'm the only person there, I stop on track, get out and pop the hood, and fluid is SPEWING from under the coolant reservoir cap. The temps of the car are almost pegged at 300.

Here's what that fun looked like:

I didn't want to get my face too close to the hot liquids, but from what I could see, nothing looked broken or cracked or disconnected. Once I realized how much fluid was being spilled, I decided to start the car and move it into the grass so it wouldn't spoil the track.

I walked back to the paddock. The track manager said I could drive my truck and trailer out onto the track to load up the car. So, that's what I did. Was kinda funny to drive my towing rig on the track. Packed up and made some phone calls to see if someone could help me.

I wanna thank Cory and Honest Assembly Garage for taking my car right away. I had just met Cory via phone on Thursday. DRLane introduced us. On Thursday, I had been talking to Cory about doing some fabrication on the car. Now, a day later, I was descending on his shop with a broken car.

As soon as I arrived, they jumped on the car. A lot of fluid had been lost, but nothing looked visually wrong--no disconnected hoses, no cracks in the reservoir, no broken hoses. They pressure tested the system. It was holding pressure. Cory had already ordered a new reservoir while I was on my way to the shop. So, they were able to quickly replace the reservoir. The best we can come up with is that the reservoir cap just gave out. I didn't have my phone with me on track when the problem occurred. I wish I could have gotten video of the fluid pouring out from under the cap. (EDIT: I guess I could have gotten the GoPro from the car......never occurred to me at the time.)

Anyway, we ran the car for quite a long time in the shop and the temps stayed down. The coolant seems fine now.

I'm experiencing another weird intermittent issue: While idling and just sitting in the paddock, sometimes the car dumps into limp mode---the rev limiter goes down to 3500 rpms, but the engine rpms actually increase...... I have to turn it off and on and then usually it's fine again. Nothing seems obvious in the codes. Cory's shop will look into this more next week. For now, I am planning on going to HPR again tomorrow/Saturday. Hopefully I can work around this issue.

As far as the splitter-----I only have three laps on it. But I will tell you this-----what I felt so far is very promising. Drove quite poorly on my 2nd hot lap and got within 0.3 sec of my personal best----did a 1:50.9. I'm not sure the tires were even fully warmed up in the cold temps. I am very excited to go out on Saturday and give the splitter another try.


Again, I want to thank Cory and the Honest Assembly Garage guys for being so welcoming. They cleared their schedule to help a guy they had never met before. I am very humbled by that. While the techs were assessing my car, Cory walked me around the shop and showed me some of the projects they've done. We're talking about original fabrication projects that haven't been done before----like making an E30 into a wild 580whp beast with an S55 motor/MCS/AP Racing. Very very cool.

[SYT_Shadow]

Originally Posted by dogbone

As soon as I arrived, they jumped on the car. A lot of fluid had been lost, but nothing looked visually wrong--no disconnected hoses, no cracks in the reservoir, no broken hoses. They pressure tested the system. It was holding pressure. Cory had already ordered a new reservoir while I was on my way to the shop. So, they were able to quickly replace the reservoir. The best we can come up with is that the reservoir cap just gave out. I didn't have my phone with me on track when the problem occurred. I wish I could have gotten video of the fluid pouring out from under the cap. (EDIT: I guess I could have gotten the GoPro from the car......never occurred to me at the time.)
.

It seems like reservoirs are something we need to replace every now and then... thanks for the PSA Mr Bone! Glad you and the car are ok!

[roastbeef]

whats the correlation between the radiator cap leaking and the high temp? is it just the seal being bad allowing for water expansion that causes the high heat?

[redpriest]

Originally Posted by dogbone

As soon as I arrived, they jumped on the car. A lot of fluid had been lost, but nothing looked visually wrong--no disconnected hoses, no cracks in the reservoir, no broken hoses. They pressure tested the system. It was holding pressure. Cory had already ordered a new reservoir while I was on my way to the shop. So, they were able to quickly replace the reservoir. The best we can come up with is that the reservoir cap just gave out. I didn't have my phone with me on track when the problem occurred. I wish I could have gotten video of the fluid pouring out from under the cap. (EDIT: I guess I could have gotten the GoPro from the car......never occurred to me at the time.)

This is interesting - one thing I've noticed is that my reservoir cap doesn't like to stay pinned to the fully shut position. I wonder if it's just a matter of time now until mine goes. Sounds like a cheap and easy replacement to do.

[rhyary]

Originally Posted by redpriest

This is interesting - one thing I've noticed is that my reservoir cap doesn't like to stay pinned to the fully shut position. I wonder if it's just a matter of time now until mine goes. Sounds like a cheap and easy replacement to do.

or have a spare

[fsmtnbiker]

Originally Posted by roastbeef

whats the correlation between the radiator cap leaking and the high temp? is it just the seal being bad allowing for water expansion that causes the high heat?

The pressurization of the cooling system is what keeps the water/coolant in it from boiling. Without that pressure the water will boil on the surfaces inside the engine creating large (and quickly expanding) steam pockets. This is what causes the huge geysers of steam coming out of the radiator cap.

At atmospheric pressure, the boiling point of water is ~212F. At 15psi it is almost 250F. This is critical to keeping the car cool.

[Exclusivs]

Originally Posted by redpriest

This is interesting - one thing I've noticed is that my reservoir cap doesn't like to stay pinned to the fully shut position. I wonder if it's just a matter of time now until mine goes. Sounds like a cheap and easy replacement to do.

You too?! Thought I was crazy...

Never remembered it being so easy to turn initially.

Chalked up to maybe more 'advanced' venting type system? No clue. Sounds like a bad design and I should replace Cap.

[Redd]

The expansion tank cap is the only thing maintaining pressure in the coolant system and it does fail. It happens in all European cars so I've made it a habit to preemptively replace it every few years. It's a cheap fix for peace of mind.

[dogbone]

Let's file this one under: Enough with the wind already!!! And seriously?.....the melting snow is doing what?

Went to High Plains Raceway on Saturday. Air temps were looking great, so I was excited to get a full day in with the new splitter along with changing the AOA of the wing and experimenting with some other damper settings.

On the way to the track, the wind started howling. There were dirt clouds blowing across the landscape.....I was hoping that maybe the track would have less wind. haha no. It was howling at the track too. Usually I ignore wind in the paddock but this was so bad and it was cool enough that I kept hiding in my pickup truck between driving sessions.

So, it was hard to get a real sense of the splitter because the car was getting tossed around. On Friday, there was no wind and, for the couple laps that I had before my coolant issues surfaced, I felt like there was some really good stuff going on. But the wind on Saturday was tough. So, I don't have any splitter report yet. I'm trying to get back to HPR before I go to COTA, but we'll see.

The day's format was open track.....which did not work in my favor. There were some very slow vehicles on track including an SUV.....

The most frustrating thing of the day was that snow was melting on the side of the track on the front straight, and was slowly creeping across the track. By early afternoon, it was all the way across the pavement and in the braking zone for Turn 1. SUPER sketchy. Was gliding on it like ice with my slicks. And then as you entered Turn 1, the tires were still wet......ooh yeah, fun. I quit early because of that.

This is never a good sight in your braking zone:




The other bummer was that I went off track once. As I was going off, I thought it was no big deal, but then once I was off the track, I realized it wasn't dirt.....it was mud.....the car was trrrrrrasssssshed with mud. I spent some time at the track cleaning it, but then once I was going through the water on the front straight, the car was trashed again.....Took me 4 hours to clean it today. It's sparkling now though!!

Anyway, regardless of the wind......I believe the wing and damper setting changes were for the positive. That's what I was focusing on----trying to understand the feel of the car.....I was very close to my PB which, given the conditions, I was happy about. Lap times were not my focus yesterday.

Also, the new coolant reservoir seemed good. Max water temps were 213ºF. So, I hope that funkiness is behind me.

On the topic of weather----the day was sunny and 50ºF. I returned the trailer to the parking lot and picked up dinner by around 6PM. As I was pulling into the driveway, there's were a few snow flurries starting to fall. By 8:30PM, it looked like this......3-4" of snow had fallen.....I wasn't aware that we were even getting any snow....glad I was able to sneak the track day in before the storm hit!



The upcoming week may be busy with car stuff. Trying to see if I can get some stuff done before COTA.

[Richbot]

Wet track + slicks = character building

[dogbone]

Originally Posted by Richbot

Wet track + slicks = character building

I remember your video from that SRF race in the rain! Crazy!

[dogbone]

Let's file this one under: Ahhhh! Awesome!!!! Ooh----that looks mean!

The new 3D end fences came in for the splitter. And all I can say is.....well, I said it above already.

Ryan was explaining a bit how they work. As air comes into the end fence, the various surface features of it capture the air and create vortices that in essence seal off the side of the splitter so that air doesn't enter the main body of the splitter from the side. By doing that, it makes the splitter more efficient because the air moving front to back isn't fighting wind from the side, and air slips more easily under the car straight back. That's also what side skirts are supposed to do. They capture the air that could potentially enter from the sides of the car so that the air going straight back isn't interrupted. These are not enormous changes. They all work together in varying degrees to make the aero aspect of the car more efficient.

Too bad we're getting 5" of snow tonight.......trying to get back out to the track before COTA! Not looking good at the moment.

Anyway, check this craziness out.

[SYT_Shadow]

That looks incredibly badass