You Learn a Lot About Cars When you Ruin Them (on Purpose)

[Mike Tries]

Exactly ;)

Cool.

My brother gave me a bunch of this neat-o bronze color wrap. Now I need to try to employ that on the car. Funny enough, the wheels that I now want to put on it are... you guessed it... silver.

I MEAN BRONZE! The wheels are bronze! Sheesh...

I need more coffee. Where's my coffee cup?

I still like blue and yellow. Maybe I can work it in somehow.

[Mike Tries]

Wheeeeeeels incoming. Konig Hypergrams. 17 x 8"

[Ryes7]

Nice wheel selection, going to look great

[Mike Tries]

I had an idea yesterday that I thought could be fun. I upgraded to a monthly plan for ChatGPT. This allows more analysis work to be done.

Why did I do that?

Good question. Get yourself a juice box.

I wanted to see if I could alter the stock tune on the car using AI. So, I set out with a plan and a credit card.

1.) See if I can upload the binary to ChatGPT at all. - Yup. It took the file.

2.) See if it understands the problem. - I told it I want to tune the Audi and it replied with, something like "Your Audi has the Bosch ME 7.5 ECU, which is well-understood and well documented. This will be fun!"

3.) See if it can dissect the file without any input from me (no maps). - Yup. It even identified relevant maps that it thought would be useful and told me what they were.

4.) See if it can identify a variable and change it without turning the file into garbage. - So far, I think it has done this. More below.

5.) See if it can do more. For example: see if it can alter or create a new map file, see if it can alter the tune in more complex ways (like disabling the nanny feature that disallows both the accelerator and brake to be pressed simultaneously).

So, it identified what it thinks is one of the VMAX scalar values. I asked it to change that value to something in MPH (it knew that the file refers to kph, and so it converted as necessary automatically). I ran file compare in Windows to see what it changed. Two byte pairs. Nothing more.

I wanted to see this in TunerPro, but the map that I have that works on the stock binary doesn't have that scalar (I still don't understand how these tunes can all be so different, and yet all work in my ECU). So I asked ChatGPT if it could alter the map file. It did, though it wasn't immediately successful. The scalar for VMAX-whatever didn't show under either Scalars or Maps. Why? Well, I took a look and it looks like it added a section under the variable(?) name %%SCALARS%%, but the xdf refers to %%CONSTANTS%% for those. I told it that it made an error here, and it.... fixed the problem. Now it shows in TunerPro.

What's next? I might ask it to adjust the top speed limiter to something like 20 kph so I can test whether it actually got the right variable. If it does this, then step 7 might involve feeding it the custom tune I'm running now, along with some log files and the xdf for that, and seeing if it can provide any feedback or improvements.

That's pretty wild stuff, right? I'm a little skeptical that it will provide me something super useful without effort on my end, but I'm also somewhat optimistic that this can work. On Monday, I described a "guy" to Suno (a music-creation AI) and told it to create music that that guy would like to play. It... made exactly the music that I wanted it to. Based on the physical description of a guy and his fictitious birthday and birth state. (The answer was, a mix of Rock/Soul/Bluegrass.) It was a pretty good song, too.

[willemml]

I asked copilot a few questions about this at work, the results were... Very wrong. But I never tried uploading the actual binary to it for tuning, interesting that it is able to modify individual bytes. I recommend figuring out what bin your ECU is using and downloading a known good XDF to check those are the bytes its modifying. If you are using the community project software version, download the XDF from reply #774 in the 1.8t community thread.

Please do continue to post updates, I am curious about the results you will get. Definitely sanity check and checksum before flashing, bootmode is a PITA.

Oh and the maps you want for left foot braking are VWPMBBR and NWPMBBR. They are vehicle and motor speed thresholds at which it becomes disabled, defaults are 3.75kph and 1200rpm (I assume this is to allow starting on a hill without rolling back in automatics).

[Mike Tries]

I might load the thing up this weekend if I have time and see if it runs and how it affects the car. I'm starting with the stock binary for now. One last test I might consider is having it change a variable that the XDF currently does identify. That way I can ask for the change, verify it with fc, and then see it in TunerPro. Actually, when I came up with this test plan, I had assumed the VMAX scalars were defined in the XDF I'm using (which might be the one from post 774... I'll double-check that later too). I was a little surprised when it didn't, but I just went with an audible and started playing with the XDF.

Sharing results and discussions like this are important. You identified a mistake I made in my testing and now I have a way to improve the testing regime. Thank you for chiming in!

[willemml]

No problem. The more open discussions there are the better. I'm really happy so see more people talking about DIY tuning over here.

Another thought I had, it might be easier to test significantly lowering the VMAX value, rather than raising it.

[Mike Tries]

That's the plan. 10 mph or so. I'll drive it around the block to see how it behaves. Er... you know... the test facility. In Mexico, or whatever. If I'm able to get anywhere with the ChatGPT tune, I'll make a thread just for that.

Next up. FMIC. It looks like there's no really solid answer on whether eBay front-mount intercoolers are good (some say they're junk, some say they're great, but most say they're all made by the same factory, so I don't know what to believe).

I can't find anything about the following scenario though: why should I remove the existing SMIC when I install the FMIC? It gets great airflow with the duct and, now, I don't even have a fog light in front of it. Why not keep it and plumb a FMIC into it?

[willemml]

I don't know anything about the eBay FMICs, they seem fine, I think the frequent argument is effective surface area/core density. With the stock turbo an Ebay FMIC will probably be ok. Sorry, also not a solid answer.

I played it "safe" and got the ER Comp (was planning to get the sport, but that was out of stock so they offered me a discount on the comp).

The stock SMIC goes where the FMIC piping needs to go, and because of the way the inlet is positioned behind the radiator mount, it is going to be difficult to route piping back there. The FMIC outlet sticks out just past where the power steering cooler lines are (on the ER Comp at least), if you compare that to where the SMIC inlet is there is a bunch of awkward routing, or rad support modification required to keep the stock SMIC.
Its probably just not worth the effort compared to the amount of cooling capacity you actually gain. My FMIC is a little over 3x bigger than the SMIC and much more than 3x heavier.

Also I imagine people who get an FMIC intending to go BT will be worried about pressure ratings, my stock SMIC exploded with only 22psi.

[Mike Tries]

All good points! OK, well, I'll see what happens with the intercooler route. Big turbo isn't happening until the Summer. Maybe Fall.

[Dr.B6Banter]

That's the plan. 10 mph or so. I'll drive it around the block to see how it behaves. Er... you know... the test facility. In Mexico, or whatever. If I'm able to get anywhere with the ChatGPT tune, I'll make a thread just for that.

Next up. FMIC. It looks like there's no really solid answer on whether eBay front-mount intercoolers are good (some say they're junk, some say they're great, but most say they're all made by the same factory, so I don't know what to believe).

I can't find anything about the following scenario though: why should I remove the existing SMIC when I install the FMIC? It gets great airflow with the duct and, now, I don't even have a fog light in front of it. Why not keep it and plumb a FMIC into it?

I've had an ebay FMIC on my car since I got it from the previous owner nearly a decade ago. My general thoughts on them is decent flow but poor heat transfer due to low fin density. A normal full width 9-12" tall ebay FMIC would still deal with heatsoak better than the stock SMIC IMO.

While you likely could plumb the SMIC into a FMIC flow ould begin to become an issue in my opinion and the cooling benifits would be outweighed by the reduction in airflow on an already undersized k03.

[Mike Tries]

How do you even know when you are starting to get heat soak issues with intercoolers, anyway? Monitor intake air temperatures? If so, what's too high? I assume the way things work is that as IATs rise, air density decreases, and the car adjusts by providing less fuel to achieve the same mixture (power decreases). But I'm wondering if it also starts to retard timing, as well, as IATs rise past a certain point to prevent detonation? I assume I'd hardly notice except for lap times with the former (less power due to decreased air density), but I'd probably notice the latter (the car pulls timing to protect itself).

[Dr.B6Banter]

Correct. ECU may add fuel to keep combustion charge cooler but the big difference is timing will get pulled as the likely hood of detonation increases significantly with increasing IATs.

Everyone has their own cut off points and “too hot” really comes down to your engine setup and risk tolerance. A relatively stock/ mild setup like yours with lower combustion pressures may be able to get away with higher temps before anything “bad” happens but really something to avoid if you can.

For context, with my eBay intercooler and a gt28 turbo, IATs went from slightly above ambient to 50c in the span of 15 seconds during a 2nd to 4th gear pull on the highway when I was doing some logging. Imagine being WOT for minutes, not just seconds. Temperatures are always the killer on track, be it coolant, oil, intake air, brakes, etc. cars designed for the road simply aren’t designed to expel the heat generated from driving on the limit for any extended period of time.


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[Mike Tries]

Crap. You're right. Buy once, cry once, right?

In other news... the Konigs showed up today. :) I'm going to go yank a wheel off of the car and get them on there for fun.

[bab73]

It's a nice project and well documented, a pleasure to read!
Tell me that 2170 lbs isn't the weight of the car?

[Nate_Conner]

Crap. You're right. Buy once, cry once, right?

In other news... the Konigs showed up today. :) I'm going to go yank a wheel off of the car and get them on there for fun.

ECS currently has a CTS FMIC as a scratch and dent, $100 off, missing a pipe and a little damage to the fins.

I got the ECS FMIC kit that ECS builds (mine is a 2.0T B7) that replaces the oil cooler, 1000% not worth the install work. its way too tight a area to

Their are also CTS kits for the same $750 price built for big turbos. I would go with those. while CTS is generally jankier shit that legit brands, their atleast actually built for the car, and through ECS, you atleast have somewhat a warranty and customer support, Ebay likely has none of that. with how much work a FMIC intercooler is, and how the car is DOA if a pipe blows, id rather have a semi decent kit that a sketch kit from Ebay, which generally isnt even all that much cheaper.

[Mike Tries]

Lol no, the actual weight is 1.2 smidgens over 3,000 pounds. The 2,170 is the hilariously-optimistic minimum weight for my car for my class based on my lackluster horsepower.

[Mike Tries]

Ladies and gentlemen, I present to you...

WHEEL STUDS!!!!

Why didn't I do this earlier! Geeze.

Note, these are very long and will not allow the stock hub caps to fit. No matter for me, as I no longer use them, but something to consider if you get studs is that you can't just get arbitrarily-long studs and expect them to fit under hub caps.

[Mike Tries]

Oh, I did other stuff too!

I made.... MORE BRACKETS!

This one is Aluminum. Ahem. AL-UM-IN-UM for my European friends.

I gave it some outward depth to allow the inside net strap to snake in behind it. I also ground down a slot for that. Then I mounted the AiM data logger's mount to the bracket, cut a square hole in it to mount the until-today-dangling "park anywhere lights" switch, and shot some paint at it.

I think it is important that the AiM be mounted rock solid so that it's not reading G force readings from whatever it is mounted to flexing. This is mounted to the dash support.

[Mike Tries]

Oh, one last thing today. It has been a year since I started this build. We got the cage built last Summer, and by Fall it was HPDE ready. In March, we got the log book, and I'd say completed the car for competiton. I thought it would be fun to recreate this picture that I took at the beginning, one year apart.





Also, here's a picture of a goose.

[Mike Tries]

Goose with hat.

[BumblebVR6]

Oh, I did other stuff too!

I made.... MORE BRACKETS!

This one is Aluminum. Ahem. AL-UM-IN-UM for my European friends.

Almost, AL-U-MIN-I-UM :-)

[Mike Tries]

Oh, I know how they say it.

[Mike Tries]

I took off yesterday to get everything finished for this weekend. I was able to find the trailer brake and (bonus nachos) the 12 volt power supply for the trailer battery charge circuit on the RV, so now I can have trailer brakes and haul the trailer with the new RV! (Did I say I bought an RV for some reason? I... did that.) The wires were just chilling inside the wiring loom, unterminated. I ran them to the new connector and we are in business now!

I also got the Audi hood open again after getting it stuck closed while I was installing the Aerocatch hood pins (so that the hood didn't keep getting stuck closed). My wife pushed down harder than my kids had been able to while I yanked on the cable. Once it opened,*I removed the OEM latch, so that won't happen again. It could use a wash, but then both vehicles are ready to rock and roll!

Oh, well, once the RV gets its new hitch. That goes on tomorrow, but I don't have to install that myself. That's a relief.

[Ryes7]

When can we see the new sexy ass wheels?

[Mike Tries]

How about now? Ish? I will have tires on there on Friday. But I mounted them for fun a week or two ago. I ceramic coated them last week so they should stay nice for longer.

[Ryes7]

How about now? Ish? I will have tires on there on Friday. But I mounted them for fun a week or two ago. I ceramic coated them last week so they should stay nice for longer.

Awesome, you are a deliverer

[Mike Tries]

Hah, thanks! Hopefully I don't wad it up this weekend during its debut race. The goal is to have some fun and bring home a shiny, functional car on Sunday.

[Kevin C]

As long as you don't do this: https://www.instagram.com/reel/DJw8mtXSO9D/

[Mike Tries]

Ahh. Yes. I am planning on NOT doing that. Hah

[Gin+]

Nice thread. Hoping for more updates.

[Mike Tries]

[Ryes7]

Looks great

[Mike Tries]

Thanks! It did well yesterday for our first race! The Hankook C5s are excellent, and I don't feel guilty pushing them hard like I kind of did with the Falken RT660s (the Falcon's didn't care, though, they were excellent tires as well). We're at NJ Motorsports Park this weekend on Lightning, and I haven't been on this track for probably 10 years, so holy smokes, this has been a weekend of busting cobwebs. I was slow, the car was slow, but we stayed out of the way and hopefully didn't slow down the other racers too much.

Today we have a 40 minute feature race. Yesterday's was only 25 minutes. Goal is just to keep it together and bring it home in one piece.

[Mike Tries]

Done! I had fun as a backmarker. Time for more camber and more horsepower.

[LeoPatrick]

Mike! Sweet thread! I'm living vicariously through your excitement! My 2003 Avant is the same spec, but unfortunately isn't tracked.

How's your experience been with the stock hood release pull? I managed to snap three of those shitty little plastic releases before eventually buying an ECS tuning billet hood release.

I'm sure that other companies make them if ECS doesn't fit your fancy. If I were tracking my car and had to get under the hood in an emergency....I'd want the billet release, or hood pins! It'd be good track insurance, just a thought, as a guy who's bitter about the 3 wasted releases he's bought.

Happy racing!

[Mike Tries]

Oh hey, yeah, the hood pins! Well, I had to do something about the factory catch because, really, the roll cage forced me to remove the original. I could have kept it there, just dangling about, but it was getting hard to release it (and it broke anyway), so I went to the Aerocatch units.

Aerocatch pins are cool. They are a pain in the tookus to install, but the key is taking your time. Also, I've heard horror stories of the Temu units failing at speed, so if you go the Aerocatch route, go with the original.

I am not running the OEM unit at all--not even as a secondary catch. (I do have two pins though, right? So there is redundancy.) I believe a lot of racing series want either OEM OR after market, but NOT both. I will eventually remove the latch and cable to get them out of the way. Probably soon, actually, as I've started pulling the core support off in anticipation of Spoolius Caesar...

You can watch the car's debut race (mine, too, as far as wheel-to-wheel goes) on the SJR SCCA's YouTube. I am in Group 6 (with USTCC). Saturday, we did qualifying in the morning and a heat race in the afternoon. Sunday, we did a longer feature race and then went home. Both days are here to watch. If anybody is interested, the videos are now chaptered, so you can find Group 6 (or any other you'd like) just by scrolling.

Saturday

https://www.youtube.com/live/aVxRvk8...re8121QHw5tHfJ

Sunday

https://www.youtube.com/live/yRHgyHB...YzvanLdSOHVun5

In-Car fun from me (camera was waaaaay too high... I was trying a new mounting position). This is just the latter half of qualifying (user error on the camera). The races will be up soon.

https://youtu.be/ze1YnCtfEdc?si=t5CPet5VLGymWD_O

Seriously, I was very slow. Slowest in the field. But... it was fun! I guess I'm happier laughing at myself and being lapped by Corvettes than waiting home for the thing to get faster.

[willemml]

Thanks for posting the video links! Your in car cam was pretty cool, that looks like so much fun.

[Mike Tries]

Thanks! The camera was mounted to a sticky pad where the sunroof used to be (just thin sheet of steel now). I had a bunch of GoPro articulated joints strung together in a long formation to try to bring it down as much as I could, but alas, the effort was in vain. I will get a roll cage clamp thingy (or print one or whatever) and just mount the thing somewhere lower, but in that same general area.

I also REALLY want to mount one in the wheel well. Now that there are no fender liners, I can put it in the lower engine compartment and get a good view of the suspension and brakes.

[Mike Tries]

I was going to do a clever write-up for all the work I just finished up with. Maybe a movie review, some random comments that don't make any sense... just pretend I did all of that. I spent 10 hours working on the suspension today, and I think I kind of pushed through doing that while feeling under the weather.

But today was a successful end to a very long struggle to get the suspension done on the Audi. I put on some adjustable upper control arms up front, as well as an ECS Tuning Coil Over kit. The upper control arms are meant to increase negative camber (so get the tops of the tires to come inward). After struggling to get the ball joints in and out (what a pain), I finally got the front done. Off to the rear, that was pretty easy. I used a rental spring compressor from Advance and lowered the subframe by almost-completely removing the bolts from each side that I was working on. Pretty easy. The rear camber bolts were seized, but I finally got them to move enough, and then I maxed those out for more negative camber.

When you do coil overs, you should use a scale. A friend loaned me his car scales, and I got to work getting the car level left-to-right, and then balanced the right way. I am at around 51% on the cross weight with a level left-to-right ride height, with my exact weight in the car. That's good enough for where I'm taking it! I also got the toe set to 1/16" toe out in the front. That should make the car turn in a little easier. -3 degrees of camber on the front right wheel, -3.5 on the front left.