heinzboehmer's 2002 Topaz 6MT Coupe

[heinzboehmer]

Hmm, I'm still not sure why a longer/raised spring is strictly necessary. The Turner plates change the location of the spring seat and shaft seat independently, so even with the same effective length for the spring, there is gain in shaft travel.

The idea of swapping to camber plates got into my mind because of this post: https://nam3forum.com/forums/forum/m...742#post181742. The Koni travel up front is extremely limited, so any gain in travel is welcome. I don't need more camber (as of right now) and didn't want to go any lower. Thought that 5mm would be okay but the occasional scrape if I don't get the angle into the driveway perfect is annoying me, so I'm going to get the spacer made (which is serving the same purpose of making the effective spring length longer).

I considered swapping out my suspension for something else (which will probably end up happening in the future), but everything I looked at involved also swapping top mounts, so I decided to start with that.

[Tbonem3]

I look at shorter stack height as a way of gaining free lowering, not so much gaining travel, but retaining travel while being able to lower the car a bit (having my cake and eating it too so to speak).

I can see why you were reluctant to not use the turner supplied bearing/washer under the poly bushing (I don't have that issue with my setup which is why I put mine up top [also to take up some of the now unnecessarily long shaft threads]). I would suggest finding a spacer that will give you the clearance you want, but is shorter than the 7mm tall turner piece.

Gizmo's right about there being the need to raise the spring or get a taller spring, but like I said at first, I look at it as "travel is fine as-is, I just want to lower the car a little more (1/4" less say) for looks and not compromise the already limited travel. This is in regards to b12 kit or similar stock style.

[heinzboehmer]

Huh, never crossed my mind that those could be there for draining water. Upper rubber spring pad has them too, so I assumed they were there to clock the two parts, but I guess that doesn't really matter when they're radially symmetrical. Water drainage makes more sense. I'll remove them from the final piece then.

Wasn't planning on 3D printing these. Realized they might be a pain to machine, but decided I'd deal with that later if I got any pushback from the manufacturer

[Bry5on]

You’ll want to get rid of those form keys, they’re likely for draining water so you don’t rust those bearings.

Are you planning to 3D print them? The geometry as is would be difficult to machine, but no problem if you eliminate the keys

[heinzboehmer]

Hmm, looks like the ios onshape app can do lidar scanning, so might try scanning the spring perch and checking interferences with the spacer. That way I can keep the keys and (hopefully) have everything fit on the first try.

[heinzboehmer]

Ended up wanting to practice my CAD skills (did very little in college, so don't have much experience at all), so designed a spacer with some bogus dimensions tonight.



Not sure I want to keep those keys on the sides and bottom. I have a feeling I'll get their geometry wrong on the first try and end up going through a couple revisions before they work. I do like that they'll make it so the spacer is unable to rotate within the spring perch, though. Plan is to make it a press fit like the factory bearing is, but still.

Anyway, I'll take the car apart later and remake the part in the correct size, then send it out to get made.

[heinzboehmer]

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.

Awesome, I'll grab those later and text you. Although from what I remember, the section where the bearing sits on the camber plate is no longer than the bearing itself, so probably can't add a spacer there.

Think it might work if the spacer goes between the bearing and the spring perch, though. Looks like there is enough room:

[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.