heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Exciting about the ducts! Especially because, if these work well... maybe a CSL bumper can finally be in my future :P

I mean, I haven't done any actual science on them. Mostly just "brakes feel good" and "nice, these pads aren't wearing as fast as I expected", but real science coming soon!

I installed the current set of girodisc dust boots before a long 3 mi Thunderhill day and cooked them without any sort of cooling. Have ordered a brand new set of girodisc dust boots and will be installing them before doing the same track day (as in, same layout, same duration and similar temps) in September. Pads will have less heat capacity because more wear, but the rest of the setup will be exactly the same. If the dust boots survive, then that'll be a pretty good indication that the scoops are doing their job.

Here ya go! Attached. You’ll just need a relevant exhaust clamp for your pipes and some fasteners.

edit: the brace parts on my car and Heinz’s car are made from 304 SS - spacer is .125” and the two brace parts are .074” thick.

The very scientific leaf blower test showed that the ducts may even work better without open bumper brake ducts. We’d need someone to A/B test that though .. maybe Heinz can break out the tape on his next track/test day.

Oh right, forgot to mention that my stock brake ducts are blocked with two of the solid wheel well liner covers. If I have some sessions left over after getting the data I need, I'll do some A/B testing with the covers on/off.

Also, uh, spacer? I think I forgot to install that...

It should be somewhere on my workbench, I'll go looking for it. I'm guessing it goes between the bracket attached to the exhaust and the bracket attached to the transmission?

[heinzboehmer]

Not off hand but I believe I used M6 x 16 or 20mm cap head screws, washer and nuts. You’ll need 4 fasteners, 2 nuts, 2 or 4 washers to suit. For the bigger SSv1 pipes, this is the clamp we’ve been using: EVIL ENERGY 2.5 Inch Exhaust... https://www.amazon.com/dp/B08HW8ZF4Z...p_mob_ap_share

Oh about the hardware. I found that you can install the brace without dropping any section of the exhaust if you use hex head screws and an open ended wrench for the transmission attachment. Not sure how you'd get the bit for the cap head screws in with section 1 in place.

[Bry5on]

the rectangular bracket seems to be missing the bend line-- got a location/bend angle for that?

Since the SS tolerances aren’t very good, and it’s usable on all exhaust pipe diameters/dimensions, it’s bend-to-fit. Super easy to bend.

Oh about the hardware. I found that you can install the brace without dropping any section of the exhaust if you use hex head screws and an open ended wrench for the transmission attachment. Not sure how you'd get the bit for the cap head screws in with section 1 in place.

I have some short allen tools that did the job for me, but yeah I think you’re right that hex head might be easier.

[Obioban]

Nice.

[Obioban]

Hopefully this doesn't function as a trans fluid heater 🤨

[0-60motorsports]

Nice.

Brother where are you ordering those from? Would love to order some.

[Bry5on]

Hopefully this doesn't function as a trans fluid heater 🤨

SS has super shitty thermal conductivity and the thermal path/impedance is very long/high. Personally not super concerned. Each layered joint (brace 1, spacer, brace 2, etc) also increases the thermal impedance which helps too.

Brother where are you ordering those from? Would love to order some.

sendcutsend.com

[Bry5on]

And earlier I wrote M6 fastener size (post since corrected). I just pulled up the CAD file and the holes are M8 clearance. So these should be M8 fasteners, not M6. Sorry, I did this a while back!

[0-60motorsports]

SS has super shitty thermal conductivity and the thermal path/impedance is very long/high. Personally not super concerned. Each layered joint (brace 1, spacer, brace 2, etc) also increases the thermal impedance which helps too.



sendcutsend.com

Awesome I emailed them the pic obi posted. Hopefully they can hook me up with just that. Cheers

[Obioban]

Awesome I emailed them the pic obi posted. Hopefully they can hook me up with just that. Cheers

Not sure if they'll just cut another set, but if it's helpful it's order number SR36A460

Otherwise, just upload the part files Bry5on linked above (post 553) and make sure all units are set to mm.

[heinzboehmer]

Hopefully this doesn't function as a trans fluid heater 🤨

Yeah not too worried about this either because of the SS. You could do titanium hardware and titanium spacer if you wanted to get super fancy, but likely superfluous.

[heinzboehmer]

Spent waay too long yesterday installing an E39 shifter vibration damper (25111434028) to try and calm down the high rpm rattle that the AS shifter makes.

Started by spending about an hour trying to get the shift knob off before giving up. I tried all the usual tricks —including opening my sunroof for the first time in years and standing on the seats— but no luck. So instead, I decided to remove the shifter and install the damper from the bottom. Removal was not hard, just annoying and time consuming. It involved taking off the snap ring that holds the spherical bearing to the carrier, disconnecting the selector rod and then pulling the shifter up into the cabin. Managed to do all of this without removing the exhaust, but it was tight.

Shifter and damper on the bench:



Aaand the damn thing doesn't fit:



Seems like the OD on the AS shifter is slightly larger than stock. I really should have measured before starting this project, but still very annoying to do all that work and then find this.

I decided to practice my sunk cost fallacy skills and try to make this work. I extended the slits, busted out the Krytox and brute forced it on:




Nice.

Here it is with everything back together:




Also did a couple other things while the car was in the air. First, I installed that spacer that I missed earlier on the exhaust brace (wow, that's hard to see in that picture, but trust me, it's there):



And second, I reprinted the broken brake scoop (living in the future is pretty great!) and installed:



You can see the interference between both parts at full droop. I was too tired to trim the dust shield parts, but they don't run into each other at ride height, so I'll just have to do it later.

Anyway, no noticeable change in driving from the scoop and exhaust brace spacer, which is good (and expected).

The damper did make a noticeable difference though. Rattle is reduced, but there is still some around ~7k rpm. It's a much less harsh rattle, so a step in the right direction. The damper also slightly improved shift feel. 420G still crunches like it always does, but the crunches are less peaky(?). It's hard to describe, but they simply feels duller and less jarring. Guess the crunches feel more damped

All in all happy with the change. I can likely tune it further by moving the damper up/down on the shifter, but that sounds like a project for some other day.

[Obioban]

Didn't even punch yourself in the face, as per tradition.

[heinzboehmer]

Didn't even punch yourself in the face, as per tradition.

Oh man if the knob had popped off when I was trying I absolutely would have.

[D-O]

Hello Heinz,

When you de-pinned and re-routed your post cat O2 harness was the wiring long enough to accommodate the OEM Euro wire guide/connector mount? My harness is not long enough to use the wire guide/mount, and I am trying to determine if I somehow did not fully extend the harness or if the shortage is to be expected.

Thanks.

D-O