Advice on seats

[h4nsm0l3m4n]

For the longest time I've been using a set of Bomz "racing" seats in my Z. These look like the generic sparco/bride/whatever knock-off racing seats that a million different sellers sell on ebay.

I bought them to replace my utterly destroyed stock seats and for $75 came at a great price. The seats are comfortable for daily driving and hold you well in corners. Once I started autocrossing though I noticed some ergonomic issues with the way the seats are positioned.

 

Here is an old picture of my car with the seats:

As you can maybe see, I have the seats as far back as they will currently fit and if I sit in the seat comfortably the top of my head rubs the headliner with my helmet. This is with me right up against the seat back (to make enough room to comfortably move my legs). If I sort of slide down more into the "well" in the middle of the seat I get a little more headroom, but now it feels like my legs more cramped than I'd like. Additionally the higher up seating position places the steering wheel low and close to my thighs.

 

Recently I had the chance to drive a bone stock Z car and was amazed how much more better the seating position felt. I had plenty of leg room and head room. However, in the corners, both me and my passenger complained of sliding off the seat. My most obvious option is to modify my seat mounts and redrill the rails to allow the seat to mount lower and move farther back as per my liking. However, given how the seats fit now (see pic above), I am skeptical how much of an improvement I can make.

 

This got me thinking are there any seats out there that mimic the stock seating position but have some bolsters to allow you to not fly off the seats in hard cornering? Many of the modern OEM and aftermarket seats look like much wider and sit higher than stock Z seats. Several of the seat install threads I've read all note this. Perhaps some sporty 80s cars have something that would fit? Anyone have any experience on what I might work?

Edited October 18, 2011 by h4nsm0l3m4n

[Leon]

I'm in a similar predicament. My 260Z still has the stock seats, but I have trouble fitting with a helmet on as I'm 6'2". Also, the roll bar is very close to the seat-back, which puts limits on seat-back thickness. I've been casually looking for a "race" seat but like you say, everything seems to place you higher than stock seats. I need the seat height to be, at worst, the same as stock and if I could find something that drops me lower then that would be awesome!

 

Good luck in your search, I'll let you know if I find something that works.

[Nelsonian]

I'm not 100% certain that these might fit the bill, but have seen some other members install the last generation rx7,(fd3s) seats into s30's. I am unaware of any other oem seats that have more bolstering and have comparable height tolerances as the stockers. I am almost positive you would have to modify the mounts or rails or both. I can tell you from first hand experience you certainly would have to modify the rails/mounts for using early bmw recaro seats, but they grip nicely.

[Leon]

Any luck, Stepan?

 

I installed some Nismo knock-off seats in my Z and they don't quite cut it. They're too small for me, while at the same time placing me higher in the car. Good for someone below 6' but not for me. I'm planning to sell them off once I find a good alternative. It's tough to find a comfy seat that also sits low enough to fit me (6'2", 190lb), especially with a helmet.

 

I really like the classy, classic race seat look (a'la "Speed" Seat from ZCCJDM) but am worried about comfort, not to mention price. Besides, I'm leary of buying seats without trying them out first.

 

I did sit in a Corbeau A4 at a local speed shop and really liked them comfort wise. The back was taller, placing the headrest in the right spot and the shoulder bolsters fit me better as well. However, I'm betting that they're going to sit me pretty high in the cabin. Still searching...

[h4nsm0l3m4n]

I actually did have some luck but it didnt end up as I originally expected.

 

I looked around quite a bit at various seats and just couldnt find something that I would be happy with. I decided my final solution would be some Kirkey aluminum race seats. These are pretty cheap, seat you about as low as physically possible, and are very light.

 

When choosing the seat I was pretty picky. I did not like the Kirkey Layback seats because the huge side bolsters looked painful to get into for a street car. The road racing seats looked good but were more expensive and I've never liked the shoulder wings. The Drag seats looked like they would be comfortable and cheap, but still had good leg/hip bolsters to keep me from moving around. I chose the Pro Street Drag seats as they looked more ergonomic than the cheaper Economy Drag seats. I designed some brackets (with additional holes so I can mount the seat higher if I wanted to) to mount the seats to the stock Z slide rails so the seats were bolted right in.

 

I've driven and raced in the Kirkeys quite a bit and am very happy. I have plenty of head room and feel like I'm sitting in a much better position overall. The seats are also pretty comfortable (2+ hour drives, no problem) and hold me pretty well when I race. I plan to add additional foam around the chest/rib level and lumbar support to fit me even better.

 

For the passenger, I kept those original knock-off seats. These were more accommodating for people of many different sizes and were an upgrade from stock Z seats. Plus I didnt care if they hit their head on the roof with their helmet

Edited July 31, 2012 by h4nsm0l3m4n

[johnc]

You can pick up 2" of headroom by cutting out the stock seat mounts and welding 1" x 2 1/2" .065" wall rectangular tubing across the floor and bolting the seats through that.

[Leon]

Great input, Stepan. I will definitely look into Kirkey. Got any photos of your seat?

 

You can pick up 2" of headroom by cutting out the stock seat mounts and welding 1" x 2 1/2" .065" wall rectangular tubing across the floor and bolting the seats through that.

Thanks John, that is another good alternative.

Edited July 31, 2012 by Leon

[JMortensen]

One thing about aluminum seats is that you really should have a seat back brace. FIA approved seats won't fold in an accident, but AL can and once the seat gives your seatbelts might not be doing what you want them to do anymore.

 

Any aftermarket seat that you put in a Z will have a weird seating position because of the slope of the stock seat brackets. The front bracket is quite a bit higher than the rear, so if you put in Recaros for example, you end up with the thigh bolsters way too high. I tried Recaros with their mounts and found my calves going to sleep after a little bit of driving. I ended up moving the rear of the seat as high as possible and modifying the sliders to lower the front, and then it was livable, but again, that's going to be a bad choice for a guy looking for helmet clearance.

 

With helmet clearance in mind I think John has the right idea. I made a 1" tall frame and attached the seat to that and it looks like it will work well with my UltraShield Rally Sport. For 6'2" you might want the 20 degree layback.

Edited July 31, 2012 by JMortensen

[SUNNY Z]

In for pics of Kirkeys.

[Leon]

One thing about aluminum seats is that you really should have a seat back brace. FIA approved seats won't fold in an accident, but AL can and once the seat gives your seatbelts might not be doing what you want them to do anymore.

 

Any aftermarket seat that you put in a Z will have a weird seating position because of the slope of the stock seat brackets. The front bracket is quite a bit higher than the rear, so if you put in Recaros for example, you end up with the thigh bolsters way too high. I tried Recaros with their mounts and found my calves going to sleep after a little bit of driving. I ended up moving the rear of the seat as high as possible and modifying the sliders to lower the front, and then it was livable, but again, that's going to be a bad choice for a guy looking for helmet clearance.

 

With helmet clearance in mind I think John has the right idea. I made a 1" tall frame and attached the seat to that and it looks like it will work well with my UltraShield Rally Sport. For 6'2" you might want the 20 degree layback.

Good points, but I do like how the seat brackets raise the front of the seat up. Gives me better thigh support.

[h4nsm0l3m4n]

The Kirkeys dont look anything special. They are actually really tall seats so depending on how you mount them may touch the plastic trim that goes across the back of the roof and around the dome light..

 

 

Regarding seat position. When I designed my mounts I was very nervous of seat height so I made multiple bolt patterns for the seats at various heights on the mount. This turned out to be mostly useless as I mounted the seat as low as possible and left it there. What I hadn't realized was, as Jon pointed out, that the stock seat mounts are not horizontal. With the 18 degree layback built into the Kirkey seat plus additional angle of the mounts it makes the seat tilt back quite a bit.

 

If I were to design new brackets I would mount the seat as low as possible and make the angle of the seat adjustable instead of height. I think this would allow me to get a more comfortable seating positon and allow the seat to be much more accommodating for other drivers.

Edited August 2, 2012 by h4nsm0l3m4n

[duragg]

This thread helpful.

I am tempted to go Ultrashield VS Halo, but concerned about egress with cage.

Ultrashield rally or road race also options..

Project creep in force now.