The truth about GT3 seats for tall drivers
 

I got my GT3 seat yesterday. I couldn't put it in until today. I took the stock seat out and set them on the ground side by side. The GT3 is as it came from Sunset Porsche with the rails and sliders. The stock seat is the same. I then took a box and set it on the floor in front of each seat. I placed one end of a level on the top of the box and held the other end above the seat (obviously level). I then measured from the bottom of the level to the center of the seating area (about 3" from the back of the seat). Your butt is exactly the same height off the floor in both seats.

So then I thought, "Well, the foam padding is definitely different. Maybe one is more compressible than the other. The GT3 seat certainly has less foam." So I decided to test it. I put the stock seat in as close to the same vertical position as the GT3 seat. To do this, I sat in the GT3 seat with my behind all the way back and my shoulders pressed firmly against the back of the seat. I had both legs stretched out straight in front of me. I then reached forward with my arms as much as possible while still keeping my shoulders pressed firmly against the seat. I marked on my knees where the tips of my fingers hit (actually, my wife did). I then sat in the stock seat in the same position and adjusted the seat until I was reaching the exact same spot. I then put each seat up against the wall. I sat as far back as possible (butt & shoulders) and sat up as tall as possible. I then had my wife set the level on my head and level it, then mark the bottom of the level where it hit the wall. Then I switched seats and did it again. The lines were identical.

So this tells me that if you are a tall guy looking to get more head room, the GT3 seat is not the answer by itself. You are going to have to spring for the BK tall man brackets and the floor mount adapter. If you want sliders, you are apparently screwed. As far as I can tell, if you removed the sliders from the GT3 seats, you would gain approximately 1" in headroom. Another option would be to remove the padding you sit on in the GT3 seat. This does lower you about an inch (I'm guessing). However, you are then sitting on the hard floor of the seat. That wouldn't be that bad, but there is an angle down right under the front part of your behind. I think that would get uncomfortable after sitting on it for about 10 minutes.

I am 6'4" with about a 35" inseam. I have been told by a few people that the only seats I could use would be the GT3 seat or the Recaro SPG XL. All other seats would have the harness holes too low, and I would be susceptible to spine compression in an accident. However, after sitting in the GT3 seat, I can see that the openings for the harness are just at the top of my shoulders. If you have a longer torso than I, the GT3 seat would be a problem in that regard also.

The upsides of the GT3 seats are that it is a racing seat; it will keep you from sliding around while you're driving hard, you can use it with a harness, and it is safe. Some people like the look of them; and for a racing seat, they don't make you look like a ricer. The downsides are: It won't give you any additional headroom without other mods, it's expensive, it's fairly narrow (I wear 36" waist pants and it's comfortable, but snug), you cannot adjust the seating angle, and some people don't care for the way it looks.

Now I just have to figure out if I should put the GT3 seat in, or sell it and put the stock seat back in.

very informative, Thanks
You saved me a lot of money as the main reason for me to get these seats would be to sit lower

The one thing I did not understand: did you get your seats from Sunset or from China (eBay)?

Mike,

How's the back angle? I'm 6' and I find that I'll sacrifice leg room and slide the seat forward and then lay the back down a little for a more comfortable ride. I'd hate to buy a set of seats and find I can't stand the fixed position. I'll stick with my stock seats, thanks for the heads-up.

I got them from Sunset. Sunset had the best price on them that I could find. I guess Porsche just raised the price on them about two weeks ago. The leather are up around $1500-1700. Sunset is selling the cloth (which I prefer) for $1166.05. Shipping was about $140 for me. It may be more though depending on how Porsche ships the seat to Sunset. I think it could be as much as $30 more.

That's a hard question to answer. I can't put a number on it because, like the stock seat, the GT3 seat back is not a straight line. I have always sat with my back at a pretty large angle too because it usually helps with the head room. However, I do find the GT3 seat to be very comfortable. It does feel very upright, but it's not so upright that it is uncomfortable.

To try to give you an idea of the seat back angle, I found a way to measure it. I set the stock seat as described above. I looked at the seat back for a flat surface, and the only part that was flat was the back side of the head support. I put a protractor on that part with the flat side against the seat. I then put a small level on the arm of the protractor. The angle it gave me was 96 degrees. If you imagine the protractor as a backward D, the arm of the protractor is pointing down at 6 degrees. That means that the top of the headrest is leaning slightly toward the front of the car. That seat position is, as far as I can tell, the same seat back position as the GT3 seat. They feel the same, or very close to it.

FWIW, I VERY carfully test fit the seat in the car. I am so far from fitting in the car with that seat, it isn't funny. Because the seat back angle is so much more upright, I can't even sit with my head upright (it's tilted on an angle) because it pushes through the headliner on the hardtop and up into the roof. Even if I took the sliders out, I still wouldn't fit in the car with the GT3 seat.

I guess that makes my mind up. I will be putting the stock seat back in.

I contacted BK to ask if the Recaro SPF XL with their mounts, or the GT3 was lower. They gave me the measurement from the seat pan to the top of the seat, which is useless. I wrote them back asking about distance from the floor to the bottom of the seat. I never got a response. So now I have no way to figure out if the SPG XL would even work for me.

Tall Guys in Boxsters
 

Hi, and thanks for the informative post. You are 6'4" with about a 35" inseam; I am 6'4" with a 34" inseam. I have only two problems. First, I have plenty of headroom but I worry about hitting my head on the roll bar if I get rear-ended (it would be a glancing blow but still . . .). Second, at times my leg will contact the cruise control stalk and my hands sometimes hit my knee when turning.

For the first problem, I am thinking of doing what Nurvus did in this post: http://www.renntech.org/forums/index.php?showtopic=11222&st=40&p=130404&#entry130 404
and photos: http://s289.photobucket.com/albums/ll216/j...nt=rollbar1.jpg

By the way, I have checked the BK web site and I can't figure out what brackets would make the stock seat any lower. Suggestions? Worthwhile?

For the second problem, there isn't much I can do other than take out the console, which I don't want to do since it isn't that big an issue. However, I have wondered whether it would be possible to use a hair dryer to heat the cruise control stalk enough to soften it and move it upwards an inch or two? Has anyone tried this?

I forgot. I meant to post this additional information.....

I sat in the car with the seat out. In other words, I was sitting directly on the floor. He eyes were about at the top of the dash. I reached up to feel how much headroom I had, and the first thing I noticed was that my head would still hit the roll bar. Did you know that in the maintenance manual they describe the plastic part on the rollbar as "padding"? I imagine that it is some sort of energy absorbing material. Yeah, you'll have a headache, but you'll be alive.

Get the GT3 delete kit. It really helps. I was skeptical about it until I drove on the track. My right hand kept hitting my right knee while turning. I got the GT3 delete kit and my hand never hits my knee any more.

When I got my GT3 seats with factory sliders I was also suprised at both the upright seating position and how high you were sitting. I got the BK brackets for factory GT3 seats that mount onto the sliding mechanism. Perfect, at least for me. They tilt the seat back more, which effectively gives you more headroom and lower the seating position about an inch as well. The BK brackets are not cheap, but made the seats work perfectly for me. Best of luck,

Ed

:cheers:

That's great information. When I had the GT3 seats in I did not bolt them down. I tried tipping the seat rearward so the front bracket came up about an inch. Based on the pictures of the BK brackets, I figured that would be at least as far as those brackets tilt the seat. That didn't help much at all. It may have gotten me an extra 1/4" or so. Maybe.

I also tried sitting in the seat without the cushion in the car. I left the front cushion on. I could sit in the seat that way for quite a long time. Most of my weight seemed to be resting on the front cushion. At 220 lbs, removing that cushion gained me about 1/2" of headroom. I was still sitting higher than in the stock seat.

I suspect that part of the problem is that the headliner in the hardtop is lower than the convertible top. I'm going to heat up the garage today and find out just how much lower.

BTW, I didn't mention it in the original post, but my car is a '99 Boxster.

If I have to get the BK brackets, I will buy the Recaro SPG XL instead. When I priced out the two seats, the GT3 seats ended up being slightly cheaper. The Recaro seat is quite a bit cheaper, but by the time you end up buying all the BK hardware to mount it, it ends up being about $75 more. If I have to buy BK brackets anyway, the Recaro will then be the cheaper solution.

Great Thread! Thanks for the detailed information.

I am (was) contemplating buying a 986, but at 6'3" with a 34" waist, the seat was going to be my first modification. Since my seat will need sliders, I think a 987 may be my only option (or a tall girlfriend).

Since Porsche designs the car, airbags, knee bolster, etc. for a wide range of body types, I think there is very little wiggle room in the driving postion.

Also, spinal compression due to improper belt height is a real issue. I had a T12 L1 burst fracture after a collision in a race due to an improper seat.

Thanks again for the great post!

A 987 is going to be a high maintenance vehicle for sure, but nothing like the cost of keeping a tall girlfriend happy.

Get the 987. It may want more of your attention, but you'll never hear about it unless you have a loose belt, a worn pulley roller, or a wheel bearing that goes out on you.

My solution
 

I am new here. Been lurking a while and decided I had something to offer.

I had the same issue in my 2002 S. I am 6'2" and 200lbs and always felt I sat to high in the car. 2 years ago I decided to solve it.

I bought 2 Recaro SPG's (non XL). They came with the stock Recaro sliders and adjustable side mounts. I then took the BK R-9040 Seat track adapter kit to mount the sliders to the floor and the mounts to the sliders. I mounted the seats as low in the brakets as they could go.

By doing this I gained around 3 inches of seat drop. Where I used to look through the top of the windshield, I now look through the middle to lower half of the windshield.

I am very satisfied with the change this made for me

Stupid Question Dept.
 

Is the vertical adjustment of the stock seat limited by the electronic whatzit that's under the driver's seat? If so, can the whatzit be relocated to under the passenger's seat? I am just looking for an inch or two additional clearance from the rollbar on the driver's side (my passenger is 5' tall and height isn't an issue). I can't see investing $1500 to $2000 for a couple of seats for a 10 year old car.

That's pretty much what I've decided to go with Mmuller. I sat in a Boxster with Pole Position seats + sliders and had much more headroom. If you look at the BK brackets, they have more adjustment holes for reclining more too. I've been told that the BK brackets will let you lower the seat even further, though I have come to trust those people less now. ;) I've also read (in only 1 place) that the Sparco slider is actually lower than the Recaro slider. BK's brackets work with the Sparco slider. I have to call BK tomorrow to ask them about that. I'll let you know what I find out.

By any chance do you still have the stock seat around? If so, could you do what I did (first measurement I described) to measure to see just how many inches lower the SPG is from the stock seat? It would require you to pull the Recaro seat to get a really accurate measure, but it would be great info for people like us.

Not that I can tell John. I looked at the stock seat pretty carefully. I was trying to figure out if there is a way I could modify it to lower it. It could be done. There is a piece of metal between the seat frame and the sliders. In the front it could save you about 3/4" to an inch. The problem is that in the back it would only save about 1/4" unless you actually modified the seat frame. Most of the space up front, I think, is for the shock that pushes the seat up when you are raising the seat. Us tall people don't care about that, so that could come out. It wouldn't help in the back though. :(

Sorry
 

Sorry, I no longer have the standard seats. I was so happy to get the seating position finally right that I was happy to let go of them.

If you want to retain the standard seat belt and buckle, you will also need to use the BK-9005 Tunnel side seat belt anchor. This gave me a mounting point at the tunnel for the buckle and allowed me to retain the use of the standard seat belt. The car has been through 2 state inspections and they always comment on the nice integration of how it looks.

I can tell you that there is no more than a quarter inch between the bottom of the seat shell and the floor of the cabin. I could go one notch lower, but I would have to machine the side brackets somewhat as the side hole for the harness would foul with the bracket.

Do you use a harness at all? BK tells me that if I go with that solution I cannot use the anti-sub strap mount bar. That kinda defeats the purpose of the race seat (other than for getting more headroom).

They tell me if I want to use an anti-sub strap mount bar, I have to go with the R-9075 side mounts with the stock sliders. That will cost me 5/8"-3/4" of headroom. I want to put in a 6-point harness for DE, but I need all the headroom I can get.

What to do? What to do?

I don't use a harness (not yet anyway) as my goal was to get comfort and safety first and then worry about track days, which is still on my to do list.

I looked at the anti sub brace just now. At least in my install, I dont see why it would not work. I dont have the BK side brackets however. Mine came with the seat and were supplied by the company I bought them from, but I can't recall who that was as it was over 3 years ago. I think it was Speedware Motorsports. I still dont see why they wouldnt work with the BK solution however

I talked to BK again. I was wondering if their R-9773 brackets would mount the Recaro seat directly to the floor. It won't. They don't have a solution to mount it without sliders (which seems odd to me). If I have to, I'll fabricate an adapter myself for track days to get that extra inch of clearance.

Anyway, while talking to them again, I found out that the R-9062 (which is for use with the Sparco or Recaro sliders) WILL work with the anti-sub bar. It's just the R-9062s and the sliders aren't drilled out for it. The guy I talked to was one of the engineers at BK and he told me that lots of people do it and it works well. So it's not a clearance issue, it's just that the parts need to be drilled. BTW, the BK guy was VERY helpful.

So what he said to do is put all of the hardware together with the seat out of the car. Determine where the sub mount bar should be located. Mark the holes. Take it all apart and drill the holes with a cobalt bit. Since the BK parts are made of stainless steel, you have to use a cobalt bit or you will go through a ton of bits trying to drill it out. Finally, put it all back together. The holes need to be drilled in the bottom of the seat side brackets, and in the top piece of the slider.

I ordered all of the stuff I'm going to need from Stable Energies. The guy I talked to there was also SUPER helpful. After I gave him the list of everything I was ordering, he offered to have one of his installers double-check to make sure that should all work. Of course I took him up on it. I should have all of it on Tuesday, so I'll update the thread with the comparison between the seats then.

My carbon fiber seats are lower than the stock seats. They are GT3 design but smaller I guess. When I first installed them I had to re-adjust my rear view mirror due to the height difference. They are for sale, check the classifieds if your interested.

I've got an update! I got the Recaro Profi SPG XL, the BK side mounts (R-9062), Recaro sliders, BK adapters (R-9040), and the BK inner seat belt mount point (R-9005).

First impressions.....

• The Recaro seat is wider than the GT3 seat. I wear a 36" waist pants and though I fit in the GT3, it was snug. Not tight, but snug. In the Recaro, I fit very nicely. I'm touching on both side pretty well, but I don't feel wedged in anymore.
• To look at the GT3 seat and the SPG XL, they appear to have the exact same design for the sides of the seats. The Recaro has higher sides to the front of the seat, whereas the GT3 has more sloping sides up front.
• The Recaro will provide for much better visibility as it narrows again above the shoulder support. The GT3 is so wide up top that it block the view (think backing up). My wife didn't mind as she could just look through the hardness holes. :D
• Just to look at them, the Recaro seat looks lower (more later).
• The GT3 wins hands down in the ease of use category. The Recaro is a PITA to put together (more later).
• The Recaro seat is heavier than the GT3 because all the BK parts are stainless steel, whereas the GT3 side supprts appear to be aluminum.

Details:
Weights -
GT3 - 26
Recaro (w/all mounting hardware) - 36
Stock - 47.5

I decided to measure a bit more accurately this time for the height of the seat (where your butt goes). What I did was use a laser level in front of the seat pointing at the seat back. I levelled the laser level then used a tape rule to make the measurements. Here's what I found....
Measuring at the furthest rearward part of seat bottom:
Stock - 5 1/8"
GT3 - 5 7/8"
Recaro - 7 1/8"
Note: These measurements are DOWN from a fixed height, therefore, the higher the number, the lower the seat. You can see that the stock seat is the highest of the seats here by about 3/4".

Measuring 5.5" out from the back of the seat. This is where I estimated that the majority of my weight is placed on the seat, and an approximation of the lowest point of my behind in the seat. Here's the numbers"
Stock - 5"
GT3 - 4 7/8"
Recaro - 6 3/8"
Note: These measurements are DOWN from a fixed height, therefore, the higher the number, the lower the seat. You can see that the stock seat is actually lower at this point than the GT3 seat by 1/8". In my book, that makes them virtually the same. The Recaro is a whopping 1 3/8" lower than the stock seat here.

Next I subjected the Recaro to the same test I performed with the other two seats to determine how high I sat in the seat. I put the seat in the same position against the wall. I sat the same way in the seat, had my wife place a level on top of my head and mark where the bottom of the level touched the wall. I really was expecting almost no difference here. I was shocked to discover that in the Recaro I sit fully 1.5" lower than in either of the other two seats (which were identical in this test).

A couple of things here that I have to mention. The GT3 seat can be mounted directly to the floor using BK side mounts. There is no such animal for the SPG XL (at least not for the Boxster). However, I did determine that if I wanted to, I could drill the existing BK side mounts and it would bolt directly down to the floor. That would gain about an additional 3/4".

The BK R-9062 mounts have one bolt hole in the rear of the seat and three in the front. This allows you, in theory to adjust the tilt of the seat. When I initially put the seat together I put it together in the top hole which would give me the most tilt. When I tried to put the seat in the car, I had to have the seat about 8" away from the back firewall. If you care about this topic at all, it is likely that you can't give up that much leg room. I know I can't. The problem is that the Recaro seat is so tall that it hits the roll bars, limiting how far back you can put the seat if it is highly reclined. The upside is that of the three seats, it is the only one where the back of my head is actually on the seat. In an impact, my head would hit the back of the seat rather than the rollbar. Yeah!

Putting the Recaro seat together is a PITA! I initially put the side mounts on the seat, then mounted the sliders to the side mounts. Can't do it. You can't reach the rear slider bolt as it is right up against the bottom of the seat. So you have to put the sliders on the side mounts first (mount the sliders as far apart as possible - in other words, the side mounts should be in as far as they will go). Then I could mount the whole assembly to the seat. The instructions suggest mounting the adapters (R-9040) to the floor, the attaching the seat. No way. I don't think you can do it that way. I'm going to mount them to the seat, then mount the whole thing in the car.

I don't know what the hell Recaro was thinking. When they made the sliders, the bolts they included are so damn long that they come in contact with the adapter bolts. This means that you cannot slide the seat. I have to run out and get shorter bolts before I can put it in the car, which means I have to put the stock seat back in for a hardware store run. <sigh>

The BK R-9005 adapters are not designed for the Boxster. The holes don't line up. They are supposed to go between the adapters and the sliders. I am going to drill a separate hole. Keep in mind that these pieces are stainless steel. Use a cobalt bit to drill them.

I don't have the seat in the car yet (see above), but I will post my impressions when I do have it in the car. Oh yeah. One more thing. By the time you buy the Recaro sliders and all of the BK parts, the Recaro SPG XL ends up costing almost exactly what the GT3 seat costs.

Well, at least now I know what Recaro was thinking. They were thinking, "Hey. 20mm are pretty common, let's use those. They might be a bit long, but so what?"

I can't find any shorter than 20mm. I need like 12mm. I just got off the phone with my Dad. A friend of his suggested calling a Japanese motorcycle dealer for the cap screw.

I found 16mm socket head cap screws in 8mm. They work great and don't hit the other bolts at all. However, I'm on Day 3 of installing this seat, and it won't be going in today. The problem is that the BK side mounts and hitting the sides of the shell. That keeps the sliders and adapters pushed out pretty far. In fact, they are about 3/8" too far apart. The holes in the floor at 16" apart, and the closest I can get the holes in the adapters is 16 3/8". I've got to call BK tomorrow. <sigh> I can, of course, grind down the part of the side mount brackets that are hitting, but I want to talk to BK before I go to that extreme. I don't know if I can even modify things enough to recover 3/8".

Needless to say, I'm not very happy with the whole process.

I did find that by mounting the seat in its full reclined position (top holes in the front), compared to mounting it in the full upright position (bottom holes in the front) makes you give up roughly 2 3/4" of leg room because of the top of the seat hitting the roll bar.

The Recaro SPG XL is finally in. It took my 4 days to finally get it in.

My problem with the brackets being too far apart in the rear was not because the side mount brackets were hitting the seat, but because the bolts attaching those brackets to the sliders were hitting the seat. This limited the amount of side-to-side movement on the sliders. My solution was to grind the head of the cap screws down at a 45 degree angle to provide more clearance. It did the trick. It was still tricky to get the seat in.

So the final results are that the Profi SPG XL is definitely lower than the GT3 seat. It is not, however, lower than the stock seat. This is due entirely to seat position. I had the stock seat reclined quite a bit in the car. The SPG XL with the BK mounts is reclined much more than the GT3 seat, but it is still much more upright than where I had the stock seat. In addition, I lost approximately 4" of leg room because the SPG XL is so tall that it hits the rollbar, which prevents it from sliding back all the way. I remove the rollbar padding on the driver side to get a tad bit more room.

If you are looking for a seat for driving on the road that will give you more room, and you never intend to drive it on the track, you may be able to find a seat that gets you lower. I'd personally recommend doing the foamectomy on your stock seats though. AFAIK, the GT3 and the Profi SPG XL are the only seats with shoulder harness openings high enough for taller drivers. The GT3 seat is definitely NOT designed for tall drivers though. The SPG XL is. It just doesn't work great in a car with rollbars like the Boxster.

I hope this info helps other people. I would have liked to have had this info prior to buying two seat.