heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Everything labeled to make the soldering step less of a pain:



Clipped into the MK60 connector:



Tried my best to keep this organized, but that's kinda impossible with ~35 2.5m long wires. The three stacks correspond to the three rows on the connector.

Ah, much better:



Top right is the connector for the brake fluid level sensor. Both the ground and signal pins need to be spliced into existing wires, so I'll leave that for later.

Also did a quick test fit:



Reaches across the engine bay to the location of the MK20 connector no problem. Crudely tested length when routing behind the dash as well:



Looks long enough for that too! It seems like I somehow managed to take accurate measurements. What a concept.

One thing I have yet to decide on is the two big ground wires on the harness. On the MK20, they run directly to the negative post inside the drug bin, but I'm not 100% sure where they come from on an MK60. It's possible that they also run to there, but they also could run to the ground post above the brake booster. Guess I need to go stare at some MK60 cars to know for sure.

For now, I'll keep the MK20 connector grounded where it is and run the MK60 grounds to the PCB I made, but this might change in the future.

[heinzboehmer]

Getting to the (actual) final stages of the project.

First had to clean up the MK20 connector I chopped off of the spare unit. Cut it down to a more reasonable size and cut a slit in the bottom of it. Yes, I went a bit too far in one spot, but it didn't actually matter. Also, the standoffs are held onto the PCB with some plastic screws on the bottom. I did this to keep consistent spacing between the board and connector.



The idea was to heat this up and then bend the plastic to create a ridge like there is on the other three sides. Of course the plastic snapped immediately, even after generous heat had been applied.



Oh well, just glued in in place instead.




Those pictures are terrible, jesus christ. You get the idea though. Better pics coming soon.

Started on the PCB work by trimming the wires on the harness so that they were all the same length and then soldering them onto the PCB.



Then the PCB went onto the connector.



It's done!

Well, not really. As is obvious in the pics, there are still some labels on the wires. Most of them are on the DSC sensor connector. I kinda measured for it, but there's a possibility that it ends up being too long and I need to trim it. Decided to keep the labels on to make that work easier for me in the future.

Then there's the two unpinned wires. Hard to spot, but you can kinda see them right under the PCB on the first harness pic. These are for m track mode (for the future) and the TPMS reset button, so they will be getting wired directly to their respective switches.

Last is that label right in the center that says something about splicing one thing into another. The brake fluid level sensor has two wires. One that gets spliced to a ground and another that gets spliced to a wire that runs from the MK60 to the instrument cluster. I still need to actually test fit the harness and am not sure exactly how long to keep these two wires, so I'll just do the splicing later. It's not a critical feature so I'm not too worried about it.

But besides that, the harness is ready to go on the car. The only thing that might annoy me is a light for the TPMS on the instrument cluster. If it does, I'll just pull the wire up (or down, need to check wiring diagrams) manually and reset it that way for now.

[heinzboehmer]

Okay now it's actually done.

Installed the DSC sensor under the driver's seat and forgot to take pictures of that. I need to go back in there to route everything permanently, so I'll take pictures then. Surprisingly, the bracket did not fit and I had to enlarge one of the holes. Unsure if that's because later cars are different or if it's because the module I bought came off of a convertible.

After that, I ran the sensor harness from the DME area to under the seat. I just followed the existing wires and clipped my wires into the wire holders alongside the others.

This is what the DME area looked like after that:



I then routed the MK60 plug to the module and spliced the brake fluid level sensor in. Also forgot to take pics here unfortunately, but here's how I (temporarily) routed it in the DME area.



I ended up zip tying the harness to the holder where the alternator cable goes to get it to the other side of the engine bay.



It was here that I realized that I probably shouldn't have an exposed PCB with power wires running to it right next to a grounded chassis, so I added some heat shrink around the whole thing. Not pretty and will do nothing for weatherproofing, but it's just a temporary solution.



Had some slack in the harness (because I made it so that it would reach well when run though the interior, not across the engine bay like this), so I coiled it up and zip tied it to one of the old MK20 mounting points. Not great for EMI, but seems to be doing fine so far. It'll get changed soon anyway.



Here's the (temporarily) final product:



And the state of the dash after all of this:



Next came the coding. Just so that I don't forget, this is what I did:

1. VA and M track mode changes
   1. Pretty much just followed this guide: https://www.ecuworx.co.uk/uploads/M-Track.pdf. Only difference was that I changed out my model year for a later one. I deleted the one that was there and added #0902. I'm pretty sure the value used doesn't matter as long as it's late enough. Did this right after step 11.
2. Sensor recalibrations
   1. Recalibrated all the sensors that INPA let me do. Half of them were new, so I figured it was worth doing (plus I was getting a steering angle/VIN fault, so that one definitely needed recalibration). Made sure I was parked on level ground (for the DSC sensor) and that the steering wheel was super straight (for the steering angle sensor).

And then it just worked!



Went out for a test drive and truly everything worked. Traction control, ABS, M track mode, everything. Hard to believe that no troubleshooting was required, but that's fine with me.

There are still two things I need to do for this project to be fully finished. First, I have to reroute the harness through the interior, but I'll do that after my upcoming track day in case something goes wrong. Second is to route the TPMS reset wire to the button in the center console. On early cars, this button goes to the DME, but it's a straight path from button to MK60 on later cars, which means I need to rerun the wire. I'll do this when I run the harness through the interior. For now, I reset the system with INPA.

Anyway, glad that this is mostly done. Now I just need to go test it on the track.

[Bry5on]

If you still haven’t done your TPMS wire routing in two weeks, we can do them together at the same time

I’m sure yours will end up being more neat than mine..

[heinzboehmer]

I'm down! I'll let you know what my plan is after the track day.

Also, in case anyone stumbles onto this thread and want to know how to do the swap, here's how: https://nam3forum.com/forums/forum/m...mk20-mk60-swap

Thoglan, this is something you might be interested in.

[Thoglan]

I'm down! I'll let you know what my plan is after the track day.

Also, in case anyone stumbles onto this thread and want to know how to do the swap, here's how: https://nam3forum.com/forums/forum/m...mk20-mk60-swap

Thoglan, this is something you might be interested in.

If I'm ever brave enough to tackle that job that thread will be invaluable. I think I'd go with the third compromise option you mention of splicing into the rear lines. Although after seeing how involved it is, I might just put up with turning traction off for the time being :P

[heinzboehmer]

If I'm ever brave enough to tackle that job that thread will be invaluable. I think I'd go with the third compromise option you mention of splicing into the rear lines. Although after seeing how involved it is, I might just put up with turning traction off for the time being :P

Yeah, if you trust your rear lines, that's definitely the way to go. Can probably even do everything from the engine bay with the intake out of the way. Do share pics if you ever do this!

[heinzboehmer]

Had a couple things to do still before my Laguna track day.

First off was fixing my rear taillights.

Since my garage is so tight, whenever I want to access both sides of the car, I usually put it up on dollies and push it around to center it. I must have not been paying a lot of attention when I did this for the MK60 swap because I ended up pulling on one of the taillights and ripped half of the lens off. Lightly pulled on the other and part of the lens came off too, so I decided to reglue them entirely.

Started by using a heat gun to go around and soften all the remaining adhesive. Then pulled then lenses from the housings:



This was harder than expected and took me quite a bit, but I managed to not break anything. I did, however, find that one of the insides was very pitted and gross looking:



I thought I might be able to clean it up with some plastic polish, but I quickly discovered that the chrome layer is super thin. Sooo don't do that. I ended up just cleaning it as much as I could with some isopropyl alcohol and left it alone. I did polish the inside of the lens, though. After that I put a bead of 3M plastic emblem and trim adhesive on the lens, stuck it back on the housing and used some masking tape to hold it on. Left it like this for 24 hours:



The adhesive worked great, but the adhesive applier (me) kinda sucked. I wasn't confident that I had fully sealed the lens against the housing, so I decided to add another layer of adhesive to act as a final seal. First I taped up the edges, trimmed everything nicely and added a tape handle to make holding the light easier:




I then smeared some more adhesive along the perimeter and took the tape off while the glue was still sort of wet. Meh, came out okay:



I'm glad that water won't get into them, but I might be on the look out for another set of these. Not fully satisfied with my repair and also have that housing with the messed up chrome.

Anyway, onto some more exciting stuff.

Swapped my transmission bushings out for the E21 bushings:



I honestly don't notice a difference. Feels pretty much the same, so would probably skip this mod if I were to do it again, especially since you have to permanently modify the brace and the damper. I did also forget to buy new exhaust gaskets, so I did this with the exhaust in place. It's possible, but it was a huge pain. Would not recommend trying to do it this way to anyone.

I then tried stuffing my track wheels into the back seat and they just barely fit:



I drove around on them for a bit after the swap and also found this in one of them:



Fortunately it was not a long screw, so it didn't puncture the tire but honestly wtf. This is the the third or fourth screw I've gotten in my tires over the last year and I've only driven around 4000 miles. What do people do that actually drive their cars around every day? Are they just patching tires every week? Or am I just extremely unlucky?

Anyway, I couldn't find a way to get them in the car that felt safe (that's why I was messing around with that cable), so I decided that I would just swap them on the car and drive to the track with them. I wanted to do a session or two with my street tires on so that the comparison between the MK20 and MK60 was a bit fairer (since I hadn't done a track day with the track tires yet), but I was already going to a different track that I had never been to before so I decided to change three variables (MK60, tires, track) instead of just two.

Regardless, I felt a HUGE difference in ABS performance. I could stomp on the brake and the car would just stop. With the MK20, the car would get twitchy and unstable under hard braking. So much so that I would have to counter steer slightly to keep it going straight. Now it just brakes in a straight line without too much drama. It's hard to explain, but it almost feels as if only the tires are doing the ABS braking now, whereas the entire car was doing it before. Previous sentence probably doesn't make too much sense, but whatever, braking is now much more confidence inspiring. I'm very happy with this.

Also messed around with traction control and m track mode. The MK60 is significantly less intrusive than the MK20. It still comes on at about the same slip threshold, but it is so much smoother. The MK20 would highly upset the entire car when it intervened, whereas the MK60 only upsets it slightly. Happy with that too, but I did end up running most of the day with traction control fully off. M track mode was kinda cool for those first warm up laps though, especially since it was cold and foggy out. It lets you drive fast but also catches you when you think the tires are up to temp, but they aren't.

And now for track day photo dump:








Don't love the editing (saturation and vibrance is ridiculous on some of them), but thought the framing was great. I'll try to see if the photographer will send me the raws, but I highly doubt it lol

Also, that red S2K is a good friend of mine. I didn't time myself, but he did. His fastest lap was a 1:56 (was also his first time at Laguna) and I was consistently a few seconds ahead of him. Not sure how many fews, so all I can say is that my fastest lap was faster than a 1:56. Not terrible for my first time there and also for not having been at the track in about six months.

And now onto post track day problems.

Was undoing all the track stuff from the car and found some fluid in the belly pan. Followed it up and saw this:



You can see the weep hole is facing forward, so I'm pretty sure the fluid didn't boil, but rather sloshed out of the reservoir under hard braking.

Ordered parts to build something similar to kaiv's catch can: https://www.m3post.com/forums/showpo...5&postcount=29. Looks like kaiv's pics are dead, but this other post has some good ones: https://www.m3post.com/forums/showpo...8&postcount=22. I know I could just put a sock on it, but I just don't want to be cleaning it up after every track day. Plus, I can never resist planning a new project.

Aaand clean:



Also flushed the PS fluid the lazy way (just the reservoir) after speaking to a friend with much more track experience about how often he flushes his.



It honestly looked fine, but I had some in the garage so whatever.

And finally, I'll end on a good note. Looks like I fixed my VANOS leak!



Or well, at least I think so. I've "fixed" it like three times in the past, but hopefully this one actually sticks.

[WestBankM4]

Track photo's look SICK Heinze.

[heinzboehmer]

Track photo's look SICK Heinze.

Thanks man!

[bigjae46]

Nice! It's almost too nice of a car to put on track.

I always suck out the PS fluid in the reservoir and replace every time I do an oil change. Keeps things fresh without running the PS pump dry and potentially damaging it doing a full fluid change.

[heinzboehmer]

Nice! It's almost too nice of a car to put on track.

I always suck out the PS fluid in the reservoir and replace every time I do an oil change. Keeps things fresh without running the PS pump dry and potentially damaging it doing a full fluid change.

Thanks! If you ever see it in person, don't look too close at it. Might change your mind about how nice it is lol

And good to know, I'll probably plan on doing the same. Every oil change seems like a reasonable interval with the amount of track days I do a year.

[heinzboehmer]

Now for a new episode of "Heinz tries to solve the 420g's sloppy shifter". To recap, I've done the following over the years:

• Replace all rubber shift bushing with poly stuff and replace everything else with stock parts.
  • This wasn't great and I'm pretty sure the poly bushing at the rear cause my shift carrier to rip out of the chassis.
• AS SSK
  • Most noticeable upgrade, went back to OE rubber bushings as well
• Remove transmission and replace all detents and springs
  • Honestly no idea if this did anything on its own, as I did it along with a clutch and the AS SSK
• Couple different shift knobs

None of this has ever made the transmission feel as good as I want it to and yet I keep thinking that the next thing will solve it.

Anyway, the next thing that will solve it is something I noticed when I was doing my MK60 swap. The AS SSK comes with its own selector rod joint and I saw that there was a bit of play between that and the selector rod. Additionally, it doesn't have the foam insert, but rather a rubber stop, so there's very little preload against the shift rod coming out of the transmission.

I decided to swap it out for a fresh genuine BMW part to see if that made any difference. Quick comparison of the two:




Put the BMW part on and there was still a similar amount of play, so I decided to shim things until it was gone. I found that the shims I used for the PS pump pressure regulator fit great onto the shaft, so I put one of those on:



This did make everything a bit too tight when reassembled, so I slowly sanded down one of the plastic washers with 800 grit sandpaper until everything felt nice.



Back on the car it went and I can happily report that it did make a difference. Made a quick video to show it (and no I didn't have to add overlays or anything because it was otherwise impossible to see, what are you talking about):

I should have measured the play before and after, but forgot to do so. However, if I measure off of the videos, it looks like the many hours of effort reduced play at the top of the knob by 3mm. All the play in the linkage is gone. Looks like the remaining play is between the pin and the shift rod on the transmission as well as within the bell housing itself.

It does seem to feel a little nicer when shifting, but I could 100% just be imagining things.

Tune in next time to watch me machine a custom selector rod joint and take the bell housing off to mess with things in there. All for an extra couple mm of play reduction. Or maybe I'll just go for the nuclear option and swap in an S6-53 transmission. George Hill sells a very nice looking kit that will probably tempt me sooner or later.

For now, I'll just have to ignore the play that's still present and tell myself that spending that much time on my back trying to install the new selector rod joint was worth it.

[Bry5on]

Did you do a selector rod joint with the exhaust and driveshaft installed? Bold strategy.

[heinzboehmer]

Did you do a selector rod joint with the exhaust and driveshaft installed? Bold strategy.

Stupid strategy is probably more apt

Decided I would give it a shot like that before removing stuff. Had it out in like 5 min, so I foolishly assumed it would be easy to install as well. Ended up spending like two hours trying to get that pin in, so yeah not exactly the best approach.