To anyone who has these brackets, I'm curious how much they're able to lower the seats, if at all on the passenger side? I'll attach some photos below of the stock seat brackets/bolts, but as you'll see there is very little clearance around the rear bolts of the drivers seat, with almost no room at all on the passenger side. The fronts have plenty of clearance to come down on both, probably over an 1.5-2" easy but if you were to lower the front without the rear the seats would be even more upright than they already are. Additionally, the passenger bracket has to mount directly to the occupancy weight sensor, not via the two mounting holes as on the drivers side seat. The photos shown on the website don't seem to depict that mounting hole location but I believe is only showing the drivers side bracket. Perhaps the passenger looks different as it says 'passenger side available upon request'.

I wouldn't mind the buckets being a bit lower and slightly more reclined so that's why I'm asking. If the results are extremely minimal however, it doesn't seem worth bothering. As it looks to me, only the drivers side seems feasible to lower the height/angle in any capacity. Cantells website claims 1.25" reduction in height but Taretts website (who also sells them) has them listed as only .75" and I've seen Ira comment here on the forums stating the same.

If anyone who has installed these could chime in or perhaps shed some light on just how these are able to change the height/angle, it would be a big help. As it stands, I'll likely leave well enough alone but I'm just curious if these make any genuine change.

Cantrell: Cantrell Motorsports 987/997 (To include Euro 991/992) Sport Seat Adjustable Side mounts - Cantrell Motorsports
Tarett: Seat Lowering Brackets, 987/997 (tarett.com)

 

I can't speak to those specific Cantrell brackets, but I've removed those bolts for other equipment like sub mount bar and first extinguisher brackets. I just remember having to use several open end wrenches with small movements as there wasn't much room for anything else.

 

And that’s the crux of my curiosity here, I just don’t see how the seat can physically be lowered any reasonable amount.

 

I'm not tyring to be cheeky, but have you considered taking out the center cushion? I've done that for track days where the helmet was touching the roof. You get a very nice "seat of your pants" connection to the car.

 

Haha no offense taken but no, that’s not a proper solution for me, although I’m sure it would afford 2-3” of additional drop. No track for mine, so I’d want everything to look as factory as it should all the time.

Surely someone must have installed these brackets. Perhaps I should cross post in the 997 GT3 forum where there’s likely more folks who have the brackets.

 

I've put those brackets on bucket seats. If you use the lowest set of holes they get you about 0.75" vertical drop. What most folks do, however, is lower the rear bracket more than the front (bottom hole in the rear and middle hole in front) to get a little extra headroom by sitting slightly reclined. This has the benefit of being very comfortable and it gives you a less "head-forward" seating position (folks who run with a HANS really notice the difference)

 

Drivers and passenger brackets or just drivers? Unless the bracket relocates the the seat fore/aft I just don’t possibly see .75” clearance to that rear bolt. That’s why I’m confused.

 

Here's a picture of the Cantrell brackets in question. Found in a Rennlist FS ad via Google search. According to Cantrell, the center holes are stock height. Mounting the seats/brackets is probably easier than the factore setup as you could have the seat on the higher setting, then install the vertical bolts, then adjust the seat downward after that.



And this photo shows the driver seat lowered on Cantrell brackets and the passenger seat on factory seat rails. Looks closer to a 1.25" difference to me.

 

If you look at the photos in this ad (Porsche GT2 Perlon Bucket Seats + Extras - Rennlist - Porsche Discussion Forums) it seems like they've even replaced the rear bolts with ones with lower profile heads for additional clearance.

Just found this thread, a lot of good info here from our own Kiwi Spyder owner @John McM .

Sport bucket seat adjust - Page 3 - Rennlist - Porsche Discussion Forums

Between needing to source seat belt bolts and possible rubbing of the bracket on the pristine carbon, it all sounds a bit of a hassle honestly. Glad I found that.

 

I did both seats. I don't remember having a problem with the passenger side, and did the same drop/tilt to the passenger side. I know Cantrell has different mounting hardware than stock and it worked pretty seamlessly for me.