heinzboehmer's 2002 Topaz 6MT Coupe

[Bry5on]

Via sendcutsend,

Delrin is available in .125, .187, .270” (3.2, 4.8, 6.9mm) and UHMW HDPE is available in .375, .500” (9.5, 12.7mm)

More options if we cut something on the waterjet here.

Get some good detailed measurements of the factory upper strut bearing and I can whip something up in CAD. Looking for OD of the bearing ID, OD of the bearing seat, length of the cylindrical section where bearing ID rests.

[heinzboehmer]

If you want the travel back, we can make you a 1/4” shim for your spring perch out of delrin or something. That would net you another 1/4” of bump travel too

Ooh interesting, might take you up on that. Shouldn't be too hard to make.

I'll need to read that thread tonight to make sure it is correct, but gaining shock shaft length is only 1 piece of the puzzle. To actually benefit from the length in shaft below the mount/plate, you need to also either lengthen the spring (install longer spring), or on existing length spring move the bottom collar up (I guess in your case would be to put a spacer/shim under the bottom of the spring). Because right now sitting lower (ride height), you are actually closer to the bump stops. And your shock shaft being longer now with new plates, just compresses the shaft into the shock body more, you did not gain bump, you gained droop. I made a few videos on shocks/springs and how to "tune" bump vs droop. Latest video on suspension (few months ago) about swapping from GC to Vorshlag plates also shows the concept.

Hmm, I think I'm missing something. I'm not sure I understand how moving the surface that the strut shaft rests on upward (towards the top of the shock tower) would result in more droop rather than bump. Ride height is lower because the thrust washer sits 5mm higher, but the strut shaft sits 10.5mm higher, so net gain of 5.5mm of strut travel.

Spring should still be compressed the same amount at rest, no? Only thing that has changed is that the strut shaft is now more extended at rest, which should mean that it has more room to travel into the shock before hitting the bump stop.

[mrgizmo04]

Yeah I think the front did go down slightly (since I now just barely scrape when backing into the garage), but I'm not sure by how much. I really should have measured the before and after. Nothing crazy though, still twoish fingers between tire and fender.

This thread says the ride height is 5mm lower, but the gain in bump travel is 5.5mm, so was okay with making the trade off: https://nam3forum.com/forums/forum/m...ate-comparison

Don't have adjustable height suspension, so just trying to make it as comfortable as possible. Idea is that the part of the Turner mount that the strut shaft rests on is shorter than the stock one, so strut will have a bit more travel before bottoming out on the bump stop.

I'll need to read that thread tonight to make sure it is correct, but gaining shock shaft length is only 1 piece of the puzzle. To actually benefit from the length in shaft below the mount/plate, you need to also either lengthen the spring (install longer spring), or on existing length spring move the bottom collar up (I guess in your case would be to put a spacer/shim under the bottom of the spring). Because right now sitting lower (ride height), you are actually closer to the bump stops. And your shock shaft being longer now with new plates, just compresses the shaft into the shock body more, you did not gain bump, you gained droop. I made a few videos on shocks/springs and how to "tune" bump vs droop. Latest video on suspension (few months ago) about swapping from GC to Vorshlag plates also shows the concept.

Sent from my SM-G950U using Tapatalk

[Bry5on]

If you want the travel back, we can make you a 1/4” shim for your spring perch out of delrin or something. That would net you another 1/4” of bump travel too

[heinzboehmer]

Assuming I understand what you are doing to regain strut travel, you will extend the shaft below mount, which will unload the spring, which will result in lower ride height, a bit more camber due to further travel in the arc and some toe out in front, concurrently resulting in more + rake and some toe in in rear, even if the shaft within the cardboard cutout stays in the same place. It will also result in more droop rather than bump, unless you shift the bottom spring collar up.

Sent from my SM-G950U using Tapatalk

Yeah I think the front did go down slightly (since I now just barely scrape when backing into the garage), but I'm not sure by how much. I really should have measured the before and after. Nothing crazy though, still twoish fingers between tire and fender.

This thread says the ride height is 5mm lower, but the gain in bump travel is 5.5mm, so was okay with making the trade off: https://nam3forum.com/forums/forum/m...ate-comparison

Don't have adjustable height suspension, so just trying to make it as comfortable as possible. Idea is that the part of the Turner mount that the strut shaft rests on is shorter than the stock one, so strut will have a bit more travel before bottoming out on the bump stop.

[heinzboehmer]

Also finally finished up the side project with the seats. Made a cushion to replace the towels that can be seen in previous posts. Decided to make it have adjustable lumbar support and a removable cover.

Started with planning out the cuts:




Since I had now used a sewing machine for more than just an hour, I figured I would be able to lay everything out directly onto the fabric. Clearly that was not the case:




For the next one, I decided to go back to the trusty CAD. Came out much neater:



For the inflatable lumbar bit, I went on eBay and got some super cheap inflatable lumbar cushions:



Removed the outer fabric layer and was left with a pretty flat inflatable bladder:



Test fitting on the fabric. Smaller than the face of the cushion, but should work well:



And now for a quick prototype made with velcro and masking tape:



Here's the range of inflation for the lumbar part:




Getting everything sewn was pretty straight forward. Starting to get kinda decent at this:




Also attached the inflatable bladder to the fabric by the top corners so it wouldn't move around too much:



Here's the structural part of the cushion done:



Next came making the outer dinamica cover. Turns out dinamica is made in ~a million colors, so it was hard to find a perfect match. I did find a vendor that stocked a color that was super close, but a yard of the stuff was $120, so I decided against it. Ended up going with another vendor that had much more reasonable prices, even though they didn't stock the exact shade of black that Cobra uses.

Meh, close enough:



Laid out the cushions onto the fabric and traced around them. Used masking tape because I was afraid of the silver marker bleeding through:




Not super obvious in the pics, but one of the cushions is taller than the other. This is because my GF said that the back cushion pushed her head forward a bit too much when set at my height, so I made a slightly shorter one for her.

Here's the finished product and how it fits over the cushion with the inflatable bit:





Since the cushions were different sizes, I used the pseudo-embroidering feature on the sewing machine to label them. This one is labeled "D" for "driver":



Some more lumbar range testing:




Looks kinda lopsided in the pics, but I think that's just because I didn't fully seat it against the seat. It's much more even in real life.

And here's the finished product:



Color match is pretty good and it definitely looks less stupid than with the towels. Still not as cool looking as how the seats come from the factory, but I can make them look normal in a few seconds, so whatever. Was also able to stuff the inflating pump thing into the substrap hole on the bottom of the seat, so no weird bits sticking out from under the bottom cushions.

Honestly this whole thing turned out pretty good. Super happy with how much more comfortable they are for street driving.

[mrgizmo04]

Assuming I understand what you are doing to regain strut travel, you will extend the shaft below mount, which will unload the spring, which will result in lower ride height, a bit more camber due to further travel in the arc and some toe out in front, concurrently resulting in more + rake and some toe in in rear, even if the shaft within the cardboard cutout stays in the same place. It will also result in more droop rather than bump, unless you shift the bottom spring collar up.

Sent from my SM-G950U using Tapatalk

[heinzboehmer]

Finally installed some Turner street camber plates I bought off of Bry5on a while back. Don't exactly have a need for more camber (yet), but I did want to regain a bit of strut travel.

Wanted to keep my alignment as close to how it was before as possible, so I made these quick cardboard templates. Not super precise, but also much better than going by eye:



Since the strut has two axes to move around in, I added some masking tape to the strut tower and marked the position of the templates in two roughly orthogonal spots. Also took the opportunity to clean things up:




Install was fairly uneventful. Took about 30 min per side and didn't hit any snags. Spent longer getting the stupid dust boot in place than I did installing the plates.

One thing I did try was swapping the location of the spacer that Turner provides. Instructions say to install between strut washer and camber plate, but I figured I'd be able to regain even more strut travel if I put it on top of the camber plate instead.

This is the spacer below the plate:



And this is with it above:



I test fitted one plate with the spacer above it and wasn't too comfortable with how close the strut washer was to the solid (black) sleeve of the plate. Here's some shitty pics of the clearance:




As you can (not) see, there's barely any space between the parts. I was concerned that they would interfere when in use, so I decided to install the spacer how Turner wants you to. Significantly more clearance that way:



Anyway, CAD templates worked well and I was able to get stuff into pretty much the same spot as before:







Haven't been driving the car around too much lately, but I'll be going to an autox at Sonoma next weekend. Hopefully these things make it so that I'm in the bump stops less.

[heinzboehmer]

You’re in this far, you should just make yourself a single insert to replace the three piece thing. You could also match the horizontal/arc stitching of the rear seats while you’re at it..

Ha, we'll see. Part of the reason why I want a separate lumbar cushion is so I can put an inflatable bladder thing into it and have adjustable lumbar support. I guess I could do it with the big cushion too, but I kinda just want to drive the car now instead of fighting against a sewing machine lol.

[Bry5on]

You’re in this far, you should just make yourself a single insert to replace the three piece thing. You could also match the horizontal/arc stitching of the rear seats while you’re at it..

[heinzboehmer]

Finished up the passenger side cushion.

One thing I did differently with this one was look up how to cut foam. I thought a hot knife would be the appropriate tool, but it turns out that a serrated knife is what you want. Grabbed a bread knife from the kitchen and tried it out:




Worked surprised well! Much better cuts than with the scissors and just as easy. Did make a mess of little foam shavings though.

Also drove the car around for a while today. Ran boring errands with it on purpose to see how comfortable the seats ended up being. Glad to say that they feel just as comfortable as the stock seats on the street now.

Took the chance to take a few phone pics:





Last thing to do is make the cushions that will go in place of the stacks of towels. Haven't made those yet because I need to get the appropriate fabric. Got some samples of dinamica in the mail the other day and found one that matches closely, so I'll be ordering that soon.

When those are done, I'll grab my camera and get some better pics of everything. I do still think that the seats look kinda stupid with the extra cushion, but the difference in comfort is insane. Was definitely worth spending my time making these.

[heinzboehmer]

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.

Finally got around to doing this. Used the reservoir kaiv mentioned and then got some nice looking fuel line and a 90 degree connector (think it's 4mm OD):



First had to decide where to mount it. I wanted it above the PS reservoir, so that any fluid that went into it would drain back. Terrible picture, but there's a good amount of space directly above the reservoir, so that's where I decided to put it:



Next I made sure that the fitting I bought wasn't too long so that it wouldn't bottom out against the cap and block the weep hole:




After that came the bracket. Considered swapping out the aux coolant pump for the non-M one so that I could build a bracket from there, but ultimately decided that there wasn't a great place to attach to bracket to. Instead, I decided to attach the bracket to the wishbone looking mount for the airbox. Solidly mounted (enough) to the chassis and super easy to access for removal.

Here's what I came up with. Nothing special, just some cuts and holes in some aluminum angle:





Dug through my pile of "I probably shouldn't throw this bolt/nut out in case I can use it in the future" things for the hardware. Think I ended up using an old, cut down VANOS bolt and a taillight nut. They were both 10mm, which is what really matters.

Before assembling everything, I did what kaiv suggested and removed the seal in the reservoir. Was able to blow through it with little effort even with the cap fully tightened.




Then cut the fuel line to size, attached both ends and wrapped them in tesa tape to avoid fraying of the outer mesh. Heat shrink tubing would probably have been a better choice from this, but that would have involved leaving the garage to get it and would have ruined the whole "I built this exclusively out of things in the garage, most of them scrap" thing I had going on.



Installed on the car:




Bolted it up so that the only thing I need to remove to open up the PS reservoir is the 90 deg elbow connector on the cap. No need to remove the catch can or anything.

There's really no way for it to interfere with the airbox with how I've positioned it, but I put the unfiltered section back on and squeezed my phone in to check just in case:



Looks good! Pretty sure the condensation inside is from me blowing through it lol. A drive should take care of that.

Felt good to tackle a project that only took a couple hours start to finish, been doing too many long winded and overly complicated things lately. Also excited to not have to clean up fluids spills after track days now.

[heinzboehmer]

Do you have any pictures of the final install of the Slon wall (as in were you able to grind away the required material on the cups)?

Did you also notice any difference/improvements after it was installed?

Still have not installed that thing, unfortunately. This is still my only car, so I'm a bit wary to loose the extra trunk space with the seats folded down, but that might change soon. Also, the adhesive I want to use for this is the same adhesive as I'll use when I do a CF roof, so I'd like to combine those two installs because of its short shelf life.

I did have a conversation with Slon about this and yeah, sounds like grinding away some of the cups is the way to go. Wrote down the important bits from that conversation here: https://nam3forum.com/forums/forum/m...585#post150585. Hope that helps!

[Mike RT4]

Jan 2022

New wheels!

Got some 18s for the street, as the 19s were quite tiring on rough roads and I wanted less unsprung mass. Tires are PS4Ss (which were not easy to source).

Front: 18x8.5" ET35 Race Silver APEX EC-7 with 235/40/18
Rear: 18x9.5" ET22 Race Silver APEX EC-7 with 265/35/18

Car looks great and (most importantly) rides a looot better.



Here's some weight data:

Front (each):

• Wheel 18": 20.4 lbs
• Tire 18": 21.6 lbs
• Wheel + tire 18": 42.1 lbs
• Wheel + tire 19": 47.9 lbs

Rear (each):

• Wheel + tire 18": 47.1 lbs
• Wheel + tire 19": 53.0 lbs

Saved 5.8 lbs per corner up front and 5.9 lbs per corner in the rear. Not bad!

Buut of course something had to happen. Drove for probably 200 mi before finding this in my left rear tire:



Ridiculous. Got it patched and all is good.


At some point, I also took my rear seats out, so I took the opportunity to test fit the Slon wall with the VinceBar cups in place. Looks great, but unfortunately does not fit that well because of the extra material that the cups add. Cups will need some grinding, but that shouldn't be terrible.

Do you have any pictures of the final install of the Slon wall (as in were you able to grind away the required material on the cups)?

Did you also notice any difference/improvements after it was installed?

[heinzboehmer]

Las thing I did was to get started on my custom seat cushion.

I talked about making an L shaped cushion before, but ultimately decided to split it up. Still going to be L shaped, but just made out of two separate pieces. This is mostly so that the sewing is simpler, but will also make the whole thing a bit more adjustable.

Started off by sketching out a cut/sew plan:



Then came translating the drawing to real things. As mentioned before, I have no idea what I'm doing. So instead of messing around with (and probably ruining) fabric, I turned to the trusty CAD:



These are the final versions of the templates that I ended up using:



Transferred onto the fabric:



The machine I got access to was honestly pretty nuts. It could do a bunch of complicated stitches and all you had to do was press the foot control and make sure the fabric was going through straight. Here's some of the stitch patterns I messed around with:



Crazy.

I do realize that me being blown away by this machine is probably the equivalent of someone being blown away by one of my torque wrenches, but I still thought it was super cool. Didn't end up using the machine for anything other than regular straight stitches, though.

Here's the first stitch I did:




And the final product:




I stiched everything inside out so that there wouldn't be flaps of fabric on the outside and tried to follow how Cobra made their cushion. Images above also show how I left a ton of extra material on the sides. Did this so that I have some room to play with if I ever want to make this cushion any thicker.

Here's the thing turned right side out:




Velcro strips are a bit crooked, but whatever. Decided to use these thinner strips because I felt that the super thick ones that Cobra uses are waay too grippy.

Then moved on to cutting out the foam. Thought that using scissors would work out well, but quickly learned that this was not the case. Edges turned out super jagged and it was really hard to make sure the cuts were orthogonal to the face of the foam:



It's good enough for now, but I want to redo the foam with some sort of hot knife thing.

Lastly, the test fit:




It fits quite well! Pretty happy with how this turned out, especially considering that I was learning how to do all this as I went along. Seat looks kinda stupid with the Cobra cushion pushed all the way up like that, but whatever, it's a lot more comfortable on the street like this,.

Next step is to replace those towels with a cushion wrapped in fabric that matches the Cobra cushions. Ordered some dinamica samples, so will get to that once I know what matches best.