Arizen Seat Installation – 2”+ Headroom Gain
 

I don’t plan to race my car, so I didn’t want to go with a full race seat & harness installation, and needed a better seat. I also intend to keep the car on the street. I am 6’3”, and tall in the torso. When I bought my car last December, the first thing I had to do was remove my headliner, which gave me about an extra inch or so of headroom. Here are some pics:

Factory seat showing my position in the car:
http://www.pbase.com/bobkat/image/14...8/original.jpg


A secondary issue I’ve had is sitting on top of the factory seat, rather than in the seat. I needed bolsters to hold me in the seat as I had to use my knees against the side panels to stabilize my body in high lateral G situation.

I’ve been watching the progress Mark at Arizen has made with his seat design which has a dropped-down butt section, which he claimed could make it so the bottom of the shell would be sitting on the floor, right down between the sliders (and I knew I wanted sliders). I was worried this portion of the seat wouldn’t be comfortable, but I went for it, and so far I'm glad I did.

It took 4 weeks for the seat to be built to my finish specifications, which was red double stitching, 2006 ZO6 logo (we discovered the 2006 logo is different from the following years), and leather. I also bought Arizen’s floor mount bracket, sliders, and seat mounting brackets.

Here are some pics of the new seat – I gained 2-3/8” of headroom:woohoo:

Arizen seat installed:
http://www.pbase.com/bobkat/image/14...7/original.jpg


Arizen seat installed – different angle:
http://www.pbase.com/bobkat/image/14...4/original.jpg


New seat bracket showing all new hardware (pic courtesy of Arizen):
http://www.pbase.com/bobkat/image/14...6/original.jpg


Here's the new seat installed showing the lower sitting position:
http://www.pbase.com/bobkat/image/14...3/original.jpg

This shows the seat belt position:
http://www.pbase.com/bobkat/image/14...9/original.jpg

Since I now have new-found headroom, I decided to reinstall the headliner. The roof looks a lot better now, and I have my sunvisors and homelink buttons back!

New seat with headliner installed:
http://www.pbase.com/bobkat/image/14...4/original.jpg

My goal was to re-use the factory belts. If you don’t want to do that and just want to install a 5 or 6 point harness, then much of the following very likely won’t apply to you. The bracket is designed to accommodate the factory belts and/or a 5 or 6 point harness. The factory seat belt mechanical installation wasn’t very difficult.

The left side belt attached easily with a 10mm X 1.5mm pitch X 20mm length class 10.9 (grade 8 equivalent) bolt. Studs are used in the factory seat, so a new bolt was needed for each seat belt. The nut has a 15mm hex head, just like all of the seat mounting nuts. I used the 3rd hole from the front of 4 mounting holes based on my seating position, which is about 1/3 travel forward from the rear-most position. The belts do not move with the seat, since they are anchored to the floor-mounted frame, so this is a matter of trying it out for your sitting position to get the best belt angle. I tried to match the angle of the factory belts.

Left seat belt attachment on factory seat:
http://www.pbase.com/bobkat/image/14...3/original.jpg

Left seat belt attachment on factory seat close-up:
http://www.pbase.com/bobkat/image/14...6/original.jpg

Left seat belt attachment on new seat without plastic cover:
http://www.pbase.com/bobkat/image/14...3/original.jpg

For the right belt receptacle, which includes the seat belt pretensioner, it was a little more work. To remove the receiver, I used a 13/16 socket. I think it’s probably a 20mm hex head, but I didn’t have anything larger than 19mm in metric. There is a steel orienting tab that fits into a slot in the factory seat frame to keep the pretensioner horizontal. I decided to dremel that tab a bit to make it fit under the bracket. Then I bent the remaining portion of the tab to shape it to follow the new frame. The result isn’t the best, as the pretensioner points up a bit instead of being horizontal, but I don’t expect it will make much of a difference. But I may revisit this to try to get it level. I’ll probably just cut the orienting tab completely off and tie-wrap the pretensioner cylinder to the frame. If I later decide to re-install the factory seat (like if I sell the car), I will just buy a new pretensioner, which I found for right around $100.

To mount the receiver to the new bracket, I used a longer bolt (30mm) of the same size as the left (10 x 1.5mm). I had to use 2 fender washers as shims to move the pretensioner away from the frame because of its shape.

Receiver/pretensioner assembly as attached to factory seat:
http://www.pbase.com/bobkat/image/14...5/original.jpg

Receiver/pretensioner assembly removed from factory seat:
http://www.pbase.com/bobkat/image/14...0/original.jpg

Receiver/pretensioner assembly orienting tab dremel work:
http://www.pbase.com/bobkat/image/14...6/original.jpg

Receiver/pretensioner assembly attached to new seat:
http://www.pbase.com/bobkat/image/14...6/original.jpg

Regarding the electrical side of things, I wanted to retain my SIR (supplemental inflatable restraint) system, with the exception of the driver side airbag, which is located within the factory seat. It is VERY important to make sure the SDM (sensing & diagnostic module) capacitors are discharged before starting to disconnect SDM components – consult your service manual. I purchased the VetteWorks Airbag Simulator Plug (ASP) set which comes with 2 connectors. One is a yellow connector to make the SDM see the same resistance as it had before from the airbag, and the other is a jumper, presumably also with a resistor, to make it look like the seat position switch is still installed. The factory seat position switch stayed with the factory seat but needs to be jumpered. These items make the airbag system “happy” in the sense that no warnings are displayed, and the hope is that the SIR system will continue to be functional if it is ever needed :ack:

When I spoke with Dan at VetteWorks, he recommended that I should either remove the seat wiring harness from under the factory seat to be reused, or buy a new one from GM. I didn’t want to cut the harness out from under the seat, as I knew I’d never get it back to original later, so I ordered a new harness for just under $100. Dan also told me I needed to remove the seat memory module from under the seat and attach it to the new wiring harness to retain the telescoping wheel function (and maybe some other functions as well). So, the new harness connects to 2 under-seat connectors, then the seat memory module (3 connectors), and the seat belt switch coming from the receiver. As you can see, the harness has a whole bunch of connectors, most of which are not used in this application.

The new seat harness (what a mess!):
http://www.pbase.com/bobkat/image/14...9/original.jpg

Under seat connectors after factory seat removed:
http://www.pbase.com/bobkat/image/14...1/original.jpg

I moved the yellow airbag/pretensioner cable from the rear hole in the carpet to the front one to avoid having it get crushed by the new seat, which is literally sitting on the floor:
http://www.pbase.com/bobkat/image/14...3/original.jpg

Seat Memory Module plugged into the new harness:
http://www.pbase.com/bobkat/image/14...1/original.jpg

Airbag simulator plug joined with the seat belt pretensioner cable to form one connector which plugs into the yellow connector coming from under the carpet:
http://www.pbase.com/bobkat/image/14...7/original.jpg

Here’s the seat position simulator jumper installed onto the appropriate harness connector (pic courtesy of VetteWorks)
http://www.pbase.com/bobkat/image/14...4/original.jpg

Overall, I am very happy with the new seat. It is very comfortable for the time I've spent in it so far. I did some local freeway cloverleaf exits at speed, and I feel like I’m connected to the car in tight turns like never before. Now that I’m sitting lower, I have more room under the steering wheel for my legs, and I am looking through the center part of the windshield, as opposed to about 1” below the top like before.

Regarding weight, my complete factory seat weighed in at 49 pounds, and the new seat weighs 33 pounds with the bracket attached.

My waist is 34 to 35 inches, and my hips are about 16” wide sitting on a tape measure, and I fit tightly in the seat, which is good. Mark has indicated the shell is 16-1/4” wide, so I’m probably right at the limit. So I guess I can’t gain any weight :eek:

As far as ease of entry and exit, the new seat is definitely more difficult to get in and out of. You sort of drop into a hole when getting in, and you have to pull yourself out of it, but that’s the price for having a seat with good bolsters. I’m developing a technique to exit where I use my right foot on the dead pedal to push out. There is still plenty of room around the steering wheel when getting in and out because the seat is mounted lower, and it’s very manageable with the wheel tilted up and telescoped in.

If you are interested in this setup and want to try out my seat and you’re in the Memphis area, you’re more than welcome to come and test the seat for fit.

Great write up!!

Thanks.

awesome write-up! I'm glad everything went smooth for you. I did both seats (not the low butt seats, but Corbeaus) and am still trying to sort out the passenger side occupancy sensor.

:iagree: Good stuff. Marc L.

Awesome write up

:iagree:

:iagree::thumbs:

We all appreciate the feedback, pictures and write-up. There are two other C6 owners that are in the process of installing seats and I'm sure this will be helpful!

We can also make a 1" wider version of this seat so feel free to contact me if that sounds like what you would need.

Mark

Here's another picture of the seat in a C5.
http://www.marradind.com/images/C5Conv1.jpg

Fantastic to see the animation/overlays of the 3 seated positions!

More than looking at the head, you can really tell how much lower the hip position is!
You are also sitting without the hunch any more, so it will save you on chiropractic bills later too.:)

Thank you for the detailed and illustrated write up.

Interesting, must be nice to fit in the car :D I'm 6' 3" as well and understand where your coming from.

When stopping at a light, can you see the light now or is it necissary to lean the head sideways to watch for the green?

It is REALLY nice to finally fit in the car! I can now see traffic lights. One of the things I noticed right away is that the sunvisor bar was previously limiting my upward vision angle, but now that I am sitting lower, I can actually see the headliner as the lowest item - not the sunvisor bar :cool:

This seat is the LX1 on the site below. It can be ordered in black cloth as well.

http://www.marradind.com/

Wow, those seat bottoms look like my fat ass would fit in them.

I've now had a chance to test the car at its limits (probably more like my limit vs. the car's :eek:), and I never would have believed a seat could really make that much of a difference, but I felt so connected to the car, that I could feel every movement the car made, and my corrections were in sync with the car's movements like never before. It made me such a better driver, that I've been smiling ever since! :woohoo:

In my particular case, I got a double bonus from this seat, as it gave me the extra headroom I needed, plus made me feel like I was a part of the car. But if I hadn't needed the extra headroom, the seat would still be totally worth the money, as now I believe that being held in position is the most important feature. Also, retaining the factory belts and airbag system, so I can still drive the car on the street, and still have enough room to enter and exit the car comfortably as compared to a full racing seat, is a major plus.

I did have an issue with the first version of the seat sliders. There was excessive lateral motion in the sliders which I could feel when tossing the car around. But when I mentioned this to Mark at Marrad (formerly known as Arizen), he told me he had a different set of sliders available, and he sent them out to me right away. This did the trick - the new sliders are nice and tight :thumbs:

Glad to hear the seat serves its purpose and your needs.

Your replacement part will be shipping this week and I'll email you tracking info when available.

Mark came up to test fit the protype of the 1" wider version in my z06 over the weekend -- I fit good and it will allow me to use a helmet without my head being pressed into the headliner or having to slouch forward. (I'd guess at 2" gained clearance on the headroom and it felt like I gained legroom too. I'm 6'4" 275lbs, not exactly a skinny frame for a racing seat. Also it was nice that it wasn't pinching my shoulders but still felt supportive. I think there is even room to go a bit wider in the bottom of the seat frame and still get in the c6 ok, but the better option would be some driver modifications. -Dan

Very nice write up. Thanks! :rock:

I'm 6'7", 215 lbs. I got my Z 6 months ago and would like to track it but don't fit with a helmet. This is a very interesting option.

I would be happy to discuss options with you by email
or pm. I am offering a free painted shell option to the first customer to order a seat with a color keyed shell so I have more options to photograph.

How much do the seats weigh vs stock. And are you guys planning on making a set out of carbon fiber or a super light one for track.