heinzboehmer's 2002 Topaz 6MT Coupe

[George Hill]

Are you just going to run the stock seat belt buckle? I've got a buddy with ABEs and the buckle is laced through the side hole. Its fine once you get in, but it sure is annoying getting in and out.

[Bry5on]

You going to run electric or manual sliders? Adding my vote here for going electric and retaining memory. It’s so nice, plus you can just set memory 3 to your rear seat access position

Post the L-R offset you calculate/use here! I’ll have to measure what I did for the sportsters but I’ve got another 5mm room to go inward or so, and the devil on my shoulder has considered designing another seat frame to use it. Also remember that the farther inward it is, the tougher it is to get in/out of the car. Especially with a bucket, which can really strain your left knee. This is the reason I sold my Z3 coupe - knee pain from getting in/out of the bucket, and I only fit in it with a bucket.

[Sharocks]

SPG XL's even if you're a slimmer waist - I'm a 31-32 depending on the holidays hehe.

PP's have the harness holes too low and the side support is meh. They're just easy to get in and out of and they look good.

[Obioban]

SPG XL’s are a total non starter with 3 points.

[Bry5on]

All the options are terrible! Just go with Porsche buckets 🤪

[bigjae46]

It's funny seeing from this angle just how far out of line the steering wheel is from the seat. Custom brackets should help with that!

I should be able to tuck the driver's seat closer to the transmission tunnel, to get some better alignment. I might even angle it slightly towards the center of the car to make it feel less offset. This will for sure restrict how far the seat can move forward, and thus, how easy it is to get into the back, but that should be alright. I can design the passenger seat bracket to prioritize a larger opening behind it when slid all the way forward, which will help a lot. I don't go back there too often these days, but it's nice to have easier access.

Those aluminum VAC/Macht Schnell adaptors are garbage. People claim safety but threading grade 8 bolts into threads that are tapped into aluminum is somehow a good idea?

Just order two sections of 3/4" T-6061 aluminum bars. Outboard will be 4" wide x 24" long, inboard will be 2" wide x 24" long. That will be enough room to center the seat. The only trick is the mountings will need to be milled out so the OEM nut/bolt fits. I used a forstener bit to countersink those holes.

I did not have any issues bolting the side mounts through the bar. You may run into clearance issues under the floor adaptor with the sheet metal. May need to mill out the bottom so that nut/bolt doesn't protrude underneath.

I use 3/8" thick compression molded carbon kevlar adaptors - 35 layers! Side mounts are bolt through with grade 8 bolts, nuts, and fender washers.

[heinzboehmer]

Are you just going to run the stock seat belt buckle? I've got a buddy with ABEs and the buckle is laced through the side hole. Its fine once you get in, but it sure is annoying getting in and out.

That's the plan! Is your buddy's receiver placed above or below that elastic divider in the side hole? Recaro advertise that divider as a safety feature that isolates the three point from a 4/5/6 harness and I think you're supposed to put the factory receiver on top, so that the elastic holds it out of the way when you get in/out. I have an email out to Recaro to confirm, but have not heard back yet.

Regardless, custom brackets should help here too. I can play with the fore/aft offset of the seat to the factory sliders to get the receiver in the correct spot. Gonna try to emulate BMW's factory placement on the F82 M4 GTS.

You going to run electric or manual sliders? Adding my vote here for going electric and retaining memory. It’s so nice, plus you can just set memory 3 to your rear seat access position

Post the L-R offset you calculate/use here! I’ll have to measure what I did for the sportsters but I’ve got another 5mm room to go inward or so, and the devil on my shoulder has considered designing another seat frame to use it. Also remember that the farther inward it is, the tougher it is to get in/out of the car. Especially with a bucket, which can really strain your left knee. This is the reason I sold my Z3 coupe - knee pain from getting in/out of the bucket, and I only fit in it with a bucket.

Funnily enough, I don't miss the electric seats at all. Sorely missed the electric mirror memory, but that has since been solved! E82 has factory manual seats, which I also have no problem with, even though that car gets driven by more people than just myself.

Will definitely post details about the brackets when I get to them! Thinking of starting with a shimmable bracket, so that I can figure out the optimal fore/aft/L/R offsets in real life, then copy those over to the CAD. Should be very easy to make those offsets parametric in the model, so that others can tweak them if they want to optimize for some other variable(s).

Fortunately, the lowest point of the PP is much wider than that of the Nogaro, so I don't think in/egress will be too much of an issue. The sides on the PP are taller, but I guess I'll just have to deal with that.

Here's both the Nogaro (blue) and PP (orange) overlaid on each other, pretty confident it'll work out!

SPG XL's even if you're a slimmer waist - I'm a 31-32 depending on the holidays hehe.

PP's have the harness holes too low and the side support is meh. They're just easy to get in and out of and they look good.

Yeah, like Obioban said, I don't like how the three points sit in them. Interestingly enough, I find the PP to be more supportive than the Nogaro, so should be more than good enough for the street. On track I'm belted in, so the side support is even less of a factor. Harnesses will work fine (for me) with the thinner bottom cushion.

All the options are terrible! Just go with Porsche buckets 🤪

Right? They all suck. It's annoying to try and make some suboptimal option work. The 997 GT3 Porsche folding buckets would be the ideal seat, but they cost about as much as the car is worth soooo

[heinzboehmer]

Those aluminum VAC/Macht Schnell adaptors are garbage. People claim safety but threading grade 8 bolts into threads that are tapped into aluminum is somehow a good idea?

Just order two sections of 3/4" T-6061 aluminum bars. Outboard will be 4" wide x 24" long, inboard will be 2" wide x 24" long. That will be enough room to center the seat. The only trick is the mountings will need to be milled out so the OEM nut/bolt fits. I used a forstener bit to countersink those holes.

I did not have any issues bolting the side mounts through the bar. You may run into clearance issues under the floor adaptor with the sheet metal. May need to mill out the bottom so that nut/bolt doesn't protrude underneath.

I use 3/8" thick compression molded carbon kevlar adaptors - 35 layers! Side mounts are bolt through with grade 8 bolts, nuts, and fender washers.

I'd like to keep the factory sliders, so current plan is to design some adapter brackets myself. I should be able to use the factory mounting points on the sliders, unlike the Brey Krause Nogaro brackets, which are designed to be bolted through some random holes on the top of the sliders. Need to figure out how to incorporate a sub strap bar cleanly into the design, but don't think it'll be a big issue.

[bavarian3]

Looking forward to watching this unfold. Perfect timing as I'm looking to get into some pole positions (or maybe just end up with sportsters) soon.

[Obioban]

I briefly had SPG XLs in my M3 wagon, and it very quickly made me realize many things I strongly wanted to avoid in a bucket seat that sees any street use. Pretty terrible choice for a street car.

[George Hill]

Is your buddy's receiver placed above or below that elastic divider in the side hole? Recaro advertise that divider as a safety feature that isolates the three point from a 4/5/6 harness and I think you're supposed to put the factory receiver on top, so that the elastic holds it out of the way when you get in/out. I have an email out to Recaro to confirm, but have not heard back yet.

[Slideways]

I'd like to see an overhead shot taken through the sunroof of a CSL seat and compare how centered the seat is in relation to the steering wheel.

[Bry5on]

I'd like to see an overhead shot taken through the sunroof of a CSL seat and compare how centered the seat is in relation to the steering wheel.

Just need a donor to scan! Beats a photo

[Slideways]

Just need a donor to scan! Beats a photo

I was going to say scan, but I don't know if karter has a 3D scanner and I did not want to give him another project

Maybe Kaiv still has his set?

[Bry5on]

I was going to say scan, but I don't know if karter has a 3D scanner and I did not want to give him another project

Maybe Kaiv still has his set?

He sold his, but if there’s anyone else in SD, you know I’m game to scan.