f4bones

My 992 GT3 Touring came with a beautiful set of Light Weight Carbon Buckets, which I love. However, as my GT3 is a "Touring", I will primarily use it on the street, the LWCBs can get old quick on longer trips. While the seats fit me well, and are very comfortable for spirited driving, the leave something to be desired for longer drives. My complaints on the LWCB are as follows:

1. The are too upright - this is a common complaint, and while there are kits to tilt them back, I find even with the tilt, it's not enough. Sitting so upright for extended periods of time makes my lower back hurt. I did install the tilt brackets, and they made a BIG difference, but I would like adjustability to fine-tune the tilt for various driving protocols.
2. No seat heat - in almost every car I have, first thing I do in the morning is turn on the heated steering wheel and seats - It doesn't need to be that cold out to make the heated seats a major plus, and this is a feature I've grown accustom to.
3. Difficult to get in and out of. While this is a learned skill, I've found it's best to put the seat in the full aft position before entering or exiting the car.
4. No seat memory - minor point, but sure would be nice to have the buttons once you fine-tune your preferences.

While searching for parts for my project GT3, I came across a few sets of NOS LWCB shells - IE the carbon fiber seat shells without the rails, foam, wiring or coverings. While they weren't cheap, they gave me an excuse to re-think this entire project. As the shells I purchased didn't have rails, it freed me up to look at alternatives. While the factory LWCB rails are available, they are somewhat expensive at around $2,000 each. And, of course, the factory rails only adjust up and down and back and forth - no tilt. I thus started to look at alternatives.

Almost all Porsches since the 996 use the same mounting rails - thus most models (Panamera, Cayman, 997/991/992, Taycan and others) will bolt right in. However, Porsche made significant changes to their seats starting with the 992 generation with different motors, electronic control, and occupancy detection. I initially purchased a few sets of Panamera seats off of ebay and stripped them down to just the rails, wiring and controls. While this is a workable solution, I came across 2 sets of Taycan seats, which share most of the same components as the 992 - the rails are identical, as are the controls. Thus, I decided to use the Taycan cores as our starting point, as the controllers are the same as the 992 14/18 ways, and thus we can probably program the memory feature. To be clear, the Panamera seat rails will work just fine, and the electronic control does not need to talk to the 992 chassis in order to work - it acts just fine as simply relays to control the motors.

In comparing the LWCB rails to the Taycan motorized rails, the LWCB rails have 1 motor, and the Taycan rails have 3 - total weight difference is around 5 lbs per seat. In my book, a 5 lb penalty is well worth it. One other interesting feature of the 992 / Taycan seats vs older generations is that the seat heating has 2 zones - IE the seat back is separate from the seat bottom, and you can adjust the balance between the 2. I initially had separated the heating circuits on the Panamera rails to allow for this, but the Taycan's already are wired this way. So first step on this quest was to reconfigure the wiring to eliminate all features except seat adjustment, seat position sensor, airbag and heating (and PODS on RH side) - IE no lumbar air system, ventilation, etc. I thus unwrapped the Taycan harness (total PITA) and removed all the superfluous wiring and then re-wrapped the harness. I then bench tested my setup, and works perfectly.

Next step will be to make some simple adapters to mount the LWCB shells to the Taycan rails. The rear mounts should only require drilling new holes and using shims in the rails. The front side, as now adjustable, will require a slightly different mounting system - the stock systems on all model seats have a bar across the front held in place to the seat by 2 "U" clamps. I will probably do something similar for the LWCB shells.

The last part of the project, and probably the most difficult will be to fabricate a switch enclosure that looks "factory" - in the new system, we only require the one lever - IE the horizontal lever on the 18 ways - lifting on the front tilts the seat, lifting on the rear raises / lowers the seat, an pushing back and forth moves seat forward / aft. Interesting is that the older Panamera control switches are interchangable with the 992 generation - IE same plug, but different housing. I bought a few of them off of ebay to experiment with. I was able to chop off all the unused controls and retain the functionality of the needed control, so now just need to fabricate a housing and integrate into the seat.

As with the other memory seats, you can program the seat to slide back when you turn off ignition and forward when on - this will be helpful in addressing my entry / exit complaint.

On the heating, pretty much any heading pad will work - just needs a 10K Ohm RTD sensor in each circuit (seat base and seat back). I removed the heater pads from Taycan foam, and I think they will work fine for the LWCBs - but have yet to test fit them. The RH side is a bit trickier, as the heater is integrated into the PODs sensor - I plan to test out the integrated Taycan pad this weekend and see if I can program with PIWIS. If not, I'll be forced to use the 992 seat sensor pad on the RH side . .

Lastly, I've ordered the memory seat button for the drivers door - I'm not quite sure what it will take to program this, nor if any additional wiring will be required, but we will soon find out! The memory / entry / exit feature will be the last step and the icing on the cake if we get it working.

Overall, this project seems to be a fairly straightforward "hack" - and I'm really looking forward to my full-power comfort-heated-tilting LWCBs!

This is the stock Taycan seat harness - before removing all the unused circuits . . . it's quite a PITA to peal back the cloth tape without accidentally cutting wires . . .

Here's the partially unwrapped harness with the extra wires removed

Testing out the slimmed-down harness before finalizing - works perfectly.

Completed harness fit to seat rails . .

Here's the stock Taycan controller - same as 992.

Here's the Panamera seat switch unit that I chopped down to only retain the needed functionality - the one slider actuates both of these switches. The switch on the left is forward / back and up / down and the forward switch is tilt.

dixonk

Following this one. The auto seat back feature would be killer. The electric tilt would be nice. Stock is too straight. The brackets made it better but I feel it needs some micro adjustment to make it perfect.

M3Inline6

I’m following as well. This is a killer project.

null

This is fantastic.

Tobeit

You are making quick progress on many fronts on your Gt3 project. Wonder how you find the time?! This one sure requires some tinkering and testing to figure it out. Bravo.

M3Inline6

He has a tinkerers man-cave. All the things up in that place. lol!

cyn

Very happy to see you tinkering with the LWCB seats. I too have a GT3T and both love and hate the seats. I'm still debating what to do and am considering swapping in a set of Recaros (with appropriate air bag null and occupancy sensor mod) or alternatively keep the LWCB and do "something" with them. What you have going here may well be that "something" so I'll watch with great interest

It strikes me there is now a third option. You state "I came across 2 sets of Taycan seats, which share most of the same components as the 992 - the rails are identical, as are the controls". Does that mean a Taycan 14/18 way seat could be swapped into a GT3T "wholesale" without modifications? I have to imagine they are quite common on ebay/wreckers sites and are reasonably priced (or are at least less then new Recaros).

f4bones

Yes, the Taycan seats will bolt right in - only issue right now is I've been unable to get the passenger occupancy sensor to calibrate. PIWIS will read the controller, but right now I can't get the sensor to calibrate. However, the seat cushion in the 992 18 ways looks exactly the same, but probably with slightly different capacitance on the sensor, so it calibrates just fine. So right now, for any seat swap, there seems to be 3 options for PODs sensor:

1. Swap in the OEM combined PODs sensor / heating pad off a 992 14/18 way seat
2. Swap in the OEM PODs sensor off the LWCB, and if heating is desired, layer in a separate heating pad on top. I've tested this and it seems to work.
3. Use PIWIS to code out occupancy sensor altogether. So far, I haven't been successful in doing this, but really haven't tried that hard. I'm 99% certain the seat can be coded to a ROW configuration w/o PODs sensor, so I'll keep exploring this option as well, as I don't think it's that important to shut the airbag off if the seat is not occupied. It of course will save some $$s in a wreck, but otherwise I don' think it provides any benefit.

I think mounting the LWCBs to the Taycan rails will be pretty slick, and really pretty straightforward. To me the power tilt is the killer feature, and will transform the seats. Add in seat heating and now we have a much improved "touring" seat.

I'm also building custom 18 ways for both my GT3s, so will that options as well. However, the 992 generation 18 ways are VERY difficult to find - so far I haven't seen a set for sale anywhere, but I'm sure they will pop up at some point. Really, swapping in the 992 18 ways is probably the best true "touring" configuration in my opinion.

tourenwagen

Awesome project! Following with interest.