My E90 M3 Dedicated Track build (with pix!)

[dogbone]

Originally Posted by roastbeef

i thought you would have gone faster on the back straight, but i guess you start from a lower speed than turn 9 at big willow.

So, I haven't gotten to any technical stuff, but in this lap----10 laps into the session at 76ºF air temps, the engine just does not pull the way it does when it's on its first lap at 52ºF.

According to the AIM, my max GPS speed on the back straight for the whole weekend was 157.3mph. I'll give you one guess when I did that. Anyway, that's quite a bit higher than the 149mph in the video.

[dogbone]

Originally Posted by Bartledoo

Have you ever thought of adding those fancy splitter diffusers to your front splitter?

Not sure what you're talking about. Do you have a pic?

[roastbeef]

Originally Posted by dogbone

So, I haven't gotten to any technical stuff, but in this lap----10 laps into the session at 76ºF air temps, the engine just does not pull the way it does when it's on its first lap at 52ºF.

According to the AIM, my max GPS speed on the back straight for the whole weekend was 157.3mph. I'll give you one guess when I did that. Anyway, that's quite a bit higher than the 149mph in the video.

oh, i understand. the video speed is from the car, but the aim tracks gps speed? makes sense.

[dogbone]

Originally Posted by roastbeef

Didn't they say the modules were included in that weight? Is there more crap to remove? Or is it all self contained?

front splitter is looking pretty tired sir.

*patiently awaiting cota impressions*

I was told by Bimmerworld that a single headlight assembly was 15.5lbs. Mine were barely 7.5lbs. There's no other items adding up to the weight loss they're claiming.

Regarding the front splitter----the reason it was wearing on the driver's side was that the support bolts had pulled out and at high speeds, the spitter was dragging. We fixed that. Honestly, I never expected the splitter to last this long. I would replace it now if the car stayed in CA, but I was thinking that since we have the dream of going to the East Coast, that it would be better to go with an old splitter since I may have a chance of going off and I would rather crunch up an old spitter than a new one.

[dogbone]

Originally Posted by roastbeef

oh, i understand. the video speed is from the car, but the aim tracks gps speed? makes sense.

No, the video speed overlay is showing GPS Speed. This 2:22 lap did not have my fastest back straight speed of the weekend. That occurred in the first session of Sunday when the air was cool.

[roastbeef]

Originally Posted by dogbone

I was told by Bimmerworld that a single headlight assembly was 15.5lbs. Mine were barely 7.5lbs. There's no other items adding up to the weight loss they're claiming.

what an odd thing to fudge numbers on...

[dogbone]

Originally Posted by maicol76

nice track car~!!!
What spec wheels and tires do you use most? rim size, offset, square or stagger and etc.

Thanks!

I have 12 rims that are all the same—-Titan-7 T-R10 Black 10.5” ET25. (Obviously I run square.)

The tire I’ve been running most over the last couple years is Pirelli DH 205/645/18. I’m required to run a Yokohama 280/650/18 slick for SuperLap Battle in two weeks. I practiced on it this weekend at COTA and thought it was nice.

[b4hand]

Ever thought of adding an ice tank for the supercharger? I guess the car is more of a few laps at once, vs 30min sessions so maybe it wouldn't benefit. Maybe E85 would help

[dogbone]

Originally Posted by OG Shark

Agh so how am I supposed to post up my 2:26 this weekend after you dropped this in here???

Haha c’mon man! Post it!!

[Bartledoo]

Originally Posted by dogbone

Not sure what you're talking about. Do you have a pic?

Here's an example. There are lots of different shapes and sizes. They supposedly add substantial front downforce. AJ Hartmann has some data on their site about them. I think they refer to them as "tunnels" though.

With your vented fenders they could give you some of that extra front bite you've been wanting. I think the ACR with fender cutouts also has them, so you could finish your matching front end.

[dogbone]

Originally Posted by Bartledoo

Here's an example. There are lots of different shapes and sizes. They supposedly add substantial front downforce. AJ Hartmann has some data on their site about them. I think they refer to them as "tunnels" though.

With your vented fenders they could give you some of that extra front bite you've been wanting. I think the ACR with fender cutouts also has them, so you could finish your matching front end.

Thanks for the pic. Interesting. I have AJ Hartmann canards. I've talked to him. Nice guy. Maybe I'll ask him for more info.

My current splitter is not chassis mounted. It's just attached to the lip. I think it could be an interesting project to make a splitter that's attached to the car in a more solid fashion and also explore making it more effective. I've heard in the past that DCT cars present more challenge for chassis mounting than 6MT cars. I've never looked at the underside to investigate chassis mounting a splitter, but the fact is that I could use more front aero, and my current splitter is beat to hell. So, this could be a good time to explore that topic.

[Ngilbe36]

Originally Posted by dogbone

I don't have video of my 2:21 fast lap. Here's how that dumb-ass moment happened. Chin Track Days sets up the first session of the day as a 40 minute session. Well, I don't need 40 minutes. So, I decided to split the session up into two smaller sessions---run 10 minutes, let the car rest for 15 minutes, then run the last 15 minutes. The strategy worked great for running laps. So, I started the camera and went out for the first 10 minutes. Then, I came in and stopped recording. Then I went back out, and guess what I forgot to turn back on.....yup, I'm a genius.

But, I did have the camera running for pretty much everything else, including the 2:22. As I said before, I really like this 2:22 because it happened as the 10th lap of the session with the oil really hot (look at the oil gauge climb) and the ambient air at 76ºF and the tires were on their 4th session. Basically, I am being more aggressive in this lap, which I'm happy about. I can't say I did everything right, but I was pushing and looking for limits.

You are in some pretty awesome company.
Congrats on the lap!
https://fastestlaps.com/tracks/circuit-of-the-americas

177. Radical RXC Turbo unknown 2:18.00
178. Porsche 911 GT3 RS (991) Brad Richards 2:22.00
179. McLaren 675LT unknown 2:23.39
180. Porsche 911 GT3 RS (991) unknown 2:23.41
181. Porsche 918 Spyder unknown 2:24.00

[dogbone]

Originally Posted by Ngilbe36

You are in some pretty awesome company.
Congrats on the lap!
https://fastestlaps.com/tracks/circuit-of-the-americas

177. Radical RXC Turbo unknown 2:18.00
178. Porsche 911 GT3 RS (991) Brad Richards 2:22.00
179. McLaren 675LT unknown 2:23.39
180. Porsche 911 GT3 RS (991) unknown 2:23.41
181. Porsche 918 Spyder unknown 2:24.00

Thanks!

Well....hehe....looking at that list, the first 175 entries are Formula 1 cars and crazy motorcycles. There are plenty of production cars that are very fast---in the 2:15-2:19 range---that aren't listed here. I've been watching videos of Corvettes and Porsches on YouTube that are impressively fast.

I said before, it would be awesome if I could take it under 2:20. I still believe it's possible. But it will take decent weather and open track.......and a car that functions properly. I remain optimistic! I believe I've got enough real world pieces of the track under my belt now that I hope I can do it.

I'm rendering a video right now that I'll post later today. There's a GMG Audi race car that I gave an immediate point-by to when we were in traffic. But then I start giving him the chase......hehe.....that car would not let me pass. I'm sitting there poised and ready to pass him on the back straight......and getting no point-by love. He could not get rid of me! I get it......Nobody wants to give the BMW sedan a point-by!! hahahahaha

[dogbone]

At COTA, on Sunday, there was a session in the early afternoon where the track was really clicking in my head. I was in constant traffic throughout the whole session and didn't set any interesting times, but I was really feeling the track, and I was just having fun learning the track and putting laps in. Anyway, I thought this session was a pretty good indicator of a Chin session and figured I'd share it.

Some notes in the video:
-The track entry is one of my least favorites at any track. Going up that hill and making us do that SUPER sharp turn sucks. They should have figured out a way to merge us in after Turn 1 half way down the hill. Someone already on track would be pointing that direction and going fairly slow when coming around the corner, so they could see you entering the track and adjust accordingly. The current way makes you hope that everyone is ok on their brakes as they're flying towards you in a straight shot. Super sketchy in my opinion. And the Pit Boss can't see what's coming down the straight due to the 8 foot high wall. He would need a spotter on a radio all day barking in his ear. They just throw you out there. I mean, not that it matters even if they could see......there were so many cars on track, there was never a gap......There were some track entries where I had to stop and wait before turning left around turn 1 because 5 cars were streaming right at me. It felt wrong to stop while going up the hill, but when you see 5 cars going 130mph straight at you, it doesn't excite you to jump into that corner......no thanks.
-4:05 - I pointed-by a GMG Audi race car in traffic, and then as the pace picked up, I was ready to pass him back, and he never gave me the point-by. For 6 minutes---almost three laps, he kept me behind him. I'm sure he was thinking, I know I ordered Amazon Express groceries, but this grocery delivery sedan is really aggressive!! He got off the track instead of pointing me by! haha!
-5:38 - the lap that starts here was a 2:24 in pretty heavy traffic. Wonder what that could have been if I had clear track. I'm barely hitting any of the marks and the time wasn't so bad.
-11:23 - a plastic bag gets caught on my splitter. This was the first time I ever caught a plastic bag on my splitter. I pitted as soon as I could because I was afraid it may be choking off my intake or maybe it was melting on something. It turns out it was not blocking anything critical. It was just caught on the splitter. I was interested that no one meatball flagged me. I decided to follow the Miata until I could get back to the pits. That way I could cruise without feeling exposed. Hey, shouldn't I get paid if I'm cleaning up trash off the racetrack???
-18:45 - that's ///Mobbin's M3. Always nice to see an E9x M3 out there! Tired of all the Porsches.....
-20:45 - It's looking like I finally have an open lap! Yay! They checker flag the session at Turn 11. Boo.

I've mentioned that I was having intermittent technical issues with the car this weekend, but in this session, the car drove normally---no mysterious revving issues. (We're thinking it could be wheel speed sensors.) And at 76ºF, I was able to stay out the whole session and drive in a spirited fashion. I wasn't trying to go sub-2:20, but still 2:24 and some 2:27s, that's not terrible pace for an E9x M3 in traffic. People assume my car just overheats instantly, but here I was chasing and driving the whole session. Ok, I had to stop for the plastic bag, but I would have been fine even if I didn't have to deal with that. I'm only bringing it up because people ask me all the time how quick the supercharger overheats. And I want to show people, you can drive in a spirited fashion on a long track and have a lot of fun with it.

[dogbone]

@flip821 Took a cool picture of the new carbon doors at Willow Springs a couple weeks ago. Figured I'd share it here.



Next up: COTA pix

[OG Shark]

Originally Posted by dogbone

@flip821 Took a cool picture of the new carbon doors at Willow Springs a couple weeks ago. Figured I'd share it here.



Next up: COTA pix

The doors are soooo good, put my fiberglass ones to shame

[72dan]

Are you ever able to take the back straight at Willow flat out with all of the aero and slicks? The hump where you lift.

Originally Posted by dogbone

It's been a very busy week with car stuff.

The carbon doors are on the car. I really like the final results. Racewerkz did a great job of installing them. There was a LOT of work required to get them on the car. (I'll talk more specifically about them later. I'm still traveling and have tons to do so I can't write in detail until I return home.)





I was able to test them at Willow Springs on Sunday. They worked great. No issues with the doors. The car is definitely faster now as a result of the weight loss. I've never gone 150mph at Willow Springs before Sunday. Fastest ever was 149.6mph. On Sunday, I hit 151.4mph on the front straight.

My goal wasn't to drive the car at it's limit on Sunday to get a new personal best. I was simply there to make sure the doors are workable at high speeds since I'll be seeing ~160mph at COTA. But-----the weather was PERFECT......ideal weather----high 55ºF. No wind. Low car count/wide open track----only 10 people in Advanced. The car accelerates better and holds the ground better. I haven't even worried about braking yet, but of course that will be better too.

I promised myself that I would not pound my new doors into the nasty rocky WSIR desert. So, I drove very much within my limits. And even still---in my fourth session, on tires that corded two sessions later, I ran a new personal best of 1:25.58.

On this lap, when I compare it to my previous best of 1:25.8, by Turn 3, I was a half second faster. But then I gave almost all of it back in Turns 3,4,5. That section of the track felt terrible yesterday. Several people were talking about it. Then I picked up a bit more time on the rest of the course. There's no doubt in my mind that on fresher tires the car can do 1:24....and possibly even dip into 1:23 if I had my act together. But I never show up with fresh tires at Willow Springs. That track is simply a tire eater. On my fast lap, after Turn 6, I had to pass some sort of luxury sedan. I am very thankful that they got way out of the way and didn't impede me at all. phew! haha

I have some aero issues to deal with today. My splitter is getting old and some support screws have pulled out. We’ll have to see if we can reattach it. Honestly, I wish I had more time to replace the splitter. It's trashed after 5 years of hard use.....darn it. Maybe I can come up with some way to get it replaced before Texas. I would have to sort out some solution this morning.....This is where living 1000 miles from the car gets complicated......

Here's the lap. Honestly, not my best driving, but the car wants to run.

Now, my sights are set on COTA. And I gotta tell ya, putting down a new fast lap at WSIR right before I go has put me in a really good mood. The car is really driving strong which makes me excited. I've been looking at the weather for the Chin Track Days event at COTA on Feb 1-2 and Day 1 looks fantastic. Day 2 may start with a bit of rain. For COTA, that seems pretty good.

Alright, time to get this busy day going. Got lots of logistics to take care of on the car and lots of miles to drive to deliver the car to San Diego for transport to Texas and then get onto a plane to go home.

[dogbone]

Originally Posted by 72dan

Are you ever able to take the back straight at Willow flat out with all of the aero and slicks? The hump where you lift.

The hump of Turn 6? No. With the supercharger, I pick up a lot of speed from the exit of Turn 5 to the top of the hill. And Turn 6 is not straight enough. The car gets tossed to the left when it’s unweighted. For a brief moment, while the car is unweighted, you are just along for the ride. So, doing like 95mph by the time I get to the hilltop and then unweighting the car and then having to turn, I just partially lift momentarily, turn the wheel as little as possible to prevent any spin potential (people spin a lot there) and then take it to the far left edge. I know it doesn’t look like much on video, but that turn is scary at speed. You’re not really in control of the car when it unweights. It’s going to sort drift and do its own thing until the weight re-settles. Could I be more aggressive there? Maybe. But that left edge of the track would come shooting at me pretty hard. In general, I would say Willow Springs is the track that I have experimented the least at. Experimentation usually leads to off-track excursions. And going into the desert of Willow Springs is super punishing to the car. The one big off I have had there was in Turn 9 and I cracked a hub and studs and was very unhappy about it. So, while I have continued to improve there slowly, I’m never big on going crazy there.

[72dan]

Gabe
I am familiar with the turn. Just wondering, I take it flat out if I set up properly in my M3 but no supercharger but also no aero. It is worth up to a full second because that speed is carried through 7 and into 8. I lift in 8 in my M3, maybe w aero I could take 8 flat out. some of the lighter cars are flat out from exit of 5 to entry of 9 so being flat out on 6 is huge for them.

Originally Posted by dogbone

The hump of Turn 6? No. With the supercharger, I pick up a lot of speed from the exit of Turn 5 to the top of the hill. And Turn 6 is not straight enough. The car gets tossed to the left when it’s unweighted. For a brief moment, while the car is unweighted, you are just along for the ride. So, doing like 95mph by the time I get to the hilltop and then unweighting the car and then having to turn, I just partially lift momentarily, turn the wheel as little as possible to prevent any spin potential (people spin a lot there) and then take it to the far left edge. I know it doesn’t look like much on video, but that turn is scary at speed. You’re not really in control of the car when it unweights. It’s going to sort drift and do its own thing until the weight re-settles. Could I be more aggressive there? Maybe. But that left edge of the track would come shooting at me pretty hard. In general, I would say Willow Springs is the track that I have experimented the least at. Experimentation usually leads to off-track excursions. And going into the desert of Willow Springs is super punishing to the car. The one big off I have had there was in Turn 9 and I cracked a hub and studs and was very unhappy about it. So, while I have continued to improve there slowly, I’m never big on going crazy there.

[nickofnicks]

any OEM parts that is still up for selling?

[dparm]

Originally Posted by dogbone

At COTA, on Sunday, there was a session in the early afternoon where the track was really clicking in my head. I was in constant traffic throughout the whole session and didn't set any interesting times, but I was really feeling the track, and I was just having fun learning the track and putting laps in. Anyway, I thought this session was a pretty good indicator of a Chin session and figured I'd share it.

Shit dude, sub-2:30 is really hauling the mail. Nicely done. Hope to see you at an event this year in TX -- come say hi!

[dparm]

Originally Posted by roastbeef

i thought you would have gone faster on the back straight, but i guess you start from a lower speed than turn 9 at big willow.

COTA is interesting in that it has some pretty fast corners that need downforce (16/17/18 complex), but also has the huge back straight that will penalize you for it. I hit about 152mph at the back straight...same as a Z06 that has 200hp on me. Talked to some Z06 owners who have the factory stage 3 (adjustable) aero, and they all swear that removing the Gurney flap makes the car way too nervous elsewhere and their lap times suffer.

Also, that back straight at COTA is not perfectly level. The first 1/3 of it is actually slightly uphill, then it levels off for the next 1/3, then you are downhill into the braking zone.