Torque Obsessed

Hi everyone, I have a FRC that is my project car / weekend toy / track toy and must satisfy my every whim, from intermittent DD to road trips to occasional track use. I've gone through several seat options now and finally found one that I like. I bought a Sparco R100 from a local BMW shop and it's in the car now. You can buy these seats from various forum vendors too. It's a tight fit in the C5, but it does fit. I'm surprised that more people haven't posted about this - I think the Sparco R100 seat is a great solution for the C5 Corvette.

Here's what I bought:
$330 Sparco R100 seat
$140 Sparco C5 seat base, part number 600SB198L
$80 Sparco universal slider set, part number SPA00493
$10 worth of M8-1.25x25 bolts, washers, and lock nuts from the orange big box hardware store
$560 total.

The seat works with the OEM seatbelt, and slides fore/aft. The side bolsters are great in corners. I'm 5'-11" 185 pounds, 36" waist, and it's actually a bit too wide for me. There's maybe 1/2 inch of space to each side, so I shift a bit to lean on the bolsters. But in a tight corner there's none of that bracing-against-the-door nonsense with these! Driving position is great for pedals/wheel/shifter with the seat as far back as it will go, and I have about an inch of headroom. It's too high for helmet use, but great on the street for now.

Update: I've tweaked the setup to install 6pt belts. Details are a few posts down from here.

Here are some crappy cell phone pics:

Torque Obsessed

With the basics out of the way, I'm going to go into more detail here.

Pro's:

• Comfy for DD use (I needed something I can drive up to 16 hours to get to the track)
• Great bolsters for turns; should work well on the track as a compromise solution
• Adjustable seat back (recline) so I can get the right angle
• Adjustable sliders to move fore/aft

Con's:

• The side bolsters are quite large, and they rub the inside of my arms. Not a problem, just not perfection.
• No 5pt/6pt harness slot
• Sitting on the Sparco frame and sliders, the seat is positioned too high for good helmet clearance, for me anyway.
• Very tight fit - the seatbelt mount and the right side seatback adjustment lever both interfere with the center tunnel, so it's very hard to get the right side of the seat frame down over the floor studs.
• Very tight fit - I think the seat rails might be able to slide back farther, but the seatbelt mount and adjustment lever are interfering with the center tunnel, preventing it from moving farther. Luckily it's in a great position now.
• Very tight fit - I had to remove the lower seatbelt retractor to get the seat in, and then reinstall the retractor. I left the trim piece off for now and would have to cut away the bottom of the trim if I wanted to reinstall it with the seat in its current position.

I'm planning to keep modding this seat until it's exactly how I want it, including:

• Paying a local upholstery shop to do the following:
  • Cut a slot in the seat base for my 6pt harness.
  • Make the side bolsters thicker (the seat is a bit too wide for me, and I want the bolsters to lock me in place like my Evo II seat did).
  • Add some back lumbar support.
• Lowering the 3pt seat belt receiver mount so that it holds the belt lower across my lap for the street. The Sparco seat frame positions the receiver a couple inches higher than it should be relative to the seat. (It's probably in the right position for other seats like the Evo II, but not for this seat.) I'll just drill another hole lower in the bracket, and then cut the top of the bracket off, which should help with the center tunnel clearance issue too.
• Removing the slider rails (I'll bolt the seat directly to the Sparco frame) to drop the seat another 1/2" to 1" so I can wear a helmet comfortably.
• Moving the seat 1/4" to 1/2" inboard to clear the seat belt retractor once the sliders are gone.
• Worst case, going to C6 belts if I need more room.

For now I'm planning to just drive it around locally for a couple of months to be sure of what I want before I go further with the above mods. It's a huge improvement over the OEM seat on the street.

Torque Obsessed

The above probably sounds like a lot of details to sweat, but anyone who's tried to find better seats for the C5 knows this is par for the course. This has been an ongoing saga for me. For what it's worth, here's what I've tried since buying the car:

Stock Seats
I bought the FRC in April 2018 and these were completely awful. Mine of course rocked back and forth as well as side to side. I almost sold the car before I realized it was the seats causing this! I thought there was something wrong with the suspension.

Corbeau A4
I had a track day planned for Memorial Day and only a few weeks to get the car ready. I ordered a set of A4s but when they arrived, they were different from the one I had sat in at the shop. They hurt my shoulders and provided no support to my back. I drove for a 3 hour round trip in the A4 and my back hurt for days afterward. I couldn't return them since I had installed one of them (for just 3 hours!) and had to sell them, losing several hundred dollars in the process. Good riddance!



Sparco Evo II
Just days before leaving for the track (driving from Atlanta to Wisconsin) I bought one of these to replace the A4s. I love this seat, mostly. It fits me like a glove and was perfect for a track day at Road America this past spring. But the shoulder wings pinch my arms, and I can't sit in it for more than 30 minutes without them hurting. That's fine at the track, where each session isn't usually more than 30 minutes. But I can't use this seat on the street, or for the drive to and from the track day events. I actually drove up to RA using the stock seat, with the Evo II sitting on the floor in the passenger side, swapped the Evo II in for the event, and then put the stock driver's seat back in to drive home. I'm hoping to visit a dozen tracks or more all over the eastern half of the US in the next few years, and I can't spend hours swapping seats each time. (I have the BK harness bar, and the extensions are a huge PITA to install/remove.) This will be up for sale in a couple months; right now it's just sitting on the floor in my bedroom looking cool.





Sparco R900
I considered this seat because it's supposedly the more comfy, better bolstered, narrower version of the R100. It sounds perfect for me, but it costs twice as much and I couldn't find anywhere to sit in one to be sure it would work for me. After the A4 nightmare, I'm not buying a seat I can't sit in beforehand.

Sparco R100
I want to get the car ready for spring, so I just bought this seat the week before Christmas and had to wait for the frame and sliders to arrive. I was able to sit in this seat for a good long while to be sure it's comfortable. It lacks the 6pt harness slot and some lumbar support, but it's fine as is. I literally bought the floor model, the actual seat I'd been sitting in, to be sure Sparco didn't ship me a newer/different seat. It's a good choice so far. It's also quite nice - the one I bought has probably had hundreds of people sitting in it in the shop over the years, and still looks like new with no visible wear or tear. I didn't even bother to clean the dust off of it before installing it, so what you see in the pics is actually a dirty seat - but it still looks great. The stitching is very nice, the seat material is a nice black cloth, and the frame is very well made. The bolsters are very robust and yet soft if you actually squeeze them. It's a great design overall. Far superior to the A4.

The difference for me is the 'wings' or whatever they're called where the seat flares out to support the shoulders.

• The A4 wings force my shoulders forward, leaving my back with no support. Super uncomfortable, from the moment I sit down.
• The Evo II wings support my shoulders nicely, causing no back issues, but the bottom of the wings pinches my arms. Also uncomfortable, over long periods of time.
• The R100 wings are hilariously above my shoulders, serving no purpose at all whatsoever aside from looking cool. The side bolsters hold me in place, and my shoulders are fully below the wings, so I don't touch them at all. If you scroll back up and look at the pics, you'll see that the A4 and Evo II wings are lower relative to the harness holes, whereas the R100 wings are at the same height as the holes. This is perfectly comfortable for me.

redzg

$560 is about half what it costs to redo the factory seats, at the end of which you still have the factory seats...

USAZR1

Appreciate the detailed write-up, TO. I'm 5'8" & 215lbs, with 38" waist. Do you think those seats will fit me?

Vetteman Jack

Nice review and good looking seat.

work_truck

you guys should add your info to this thread if you haven't already!

https://www.corvetteforum.com/forums...ar-thread.html

Torque Obsessed

I didn't even know about this thread! Thanks for mentioning it, I'll add a post.

Torque Obsessed

I think so. They're a bit wide for me, to the point that I want to add a bit more bolstering to the sides to make them a tighter fit. So I think they should fit you as well. If you're ever in Atlanta, let me know. You're welcome to drop by to see for yourself.

work_truck

happy to help, its a great thread!

The big thing that helped me find a seat was being able to find what already fit and comparing the dimensions, so I really appreciate the people that add to the list!

Beer:30

Great thread and install.


I looked on the website at the seat bracket/base and see "For use on racing vehicles which may never be used upon a highway"

Is this a concern? Just a disclaimer?

Thanks!

Zeek

Yeah but $560 is for one seat....Does it cost over a grand to redo one factory seat?

Torque Obsessed

Sounds like a disclaimer. The seat bracket/base may not comply with some obscure law somewhere, or maybe they're just protecting themselves legally in case of who-knows-what. Certainly not something I'm worried about.

Torque Obsessed

Updates!! I'm all finished dialing things in.

• I hit the seat frame legs with a hammer until they were squished a bit lower. This dropped the back of the seat nicely so that it has a nice rake to it, and created just enough clearance for my helmet.
• I slotted the legs (since squishing them changed the mounting hole location) diagonally to shift the rear of the seat inboard 1/4". This made it super easy to install the seat; it drops right in now.
• I shortened the seatbelt mounting tab and drilled a new hole 2" lower.
• I shortened the OEM seatbelt latch assembly. This and shortening the mounting tab moved it much lower so the OEM belt sits nice and tight across my lap.
• I added the mounting hardware for my 6pt belts.
• I opened up the stitching between the seat panels and removed some foam to create a sub belt pass-through.

I'm thrilled with the results. It's super comfy; the 6pt belts work great; and the ergonomics are perfect. I didn't think it was possible to have a comfortable, supportive, great looking seat in the C5 at all, let alone one that works with 6pt belts. This took about 10 hours of hammering and drilling and grinding and filing, and I'm blown away by the results. It feels like it was custom made for me.







You might notice a couple of things. There was no room to mount a latch for the right side lap belt, so I just put a bolt through the seat frame with a big washer on top. Also there's a nice 3/4" metal bar going across the bottom of the seat (part of the seat itself) that is perfect to route the sub belts around so they can come up vertically right where I need them. And I left the OEM driver's seat controller hooked up to prevent the car from missing it. (Not shown in the pics; I removed it while I was working.) It and the wiring harness all fit nicely under the seat; there's plenty of room.

This has turned out to be a really awesome seat solution for the C5. I could sew some fabric around the sub belt opening or pay an upholstery shop to do it, but honestly I don't care; it's fine for me as is.

redzg

Looks to me as though you should be. Thrilled and somewhat proud. Lot of good work, and impressive thinking it through. Well done.

Jackie N

I had R100s in my Datsun for a few weeks but they really didn't fit well in such a small car so I sold them. They are a tremendous value and I was very happy with them as a product.

With all that out of the way, are you not worried that all that hammering and bending of mounting tabs compromised their strength?

After going through similar hell to fit them in my old car, and now reading about your experience, I'm not sure I wanna attempt it again. I have race seats now mounted on the stock motorized mount and they fit the car really well, only issue being how they interface with the stock seatbelt.

Beer:30

Need to look into these.

Torque Obsessed

That is a risk I would have preferred not to take, but one I'll have to live with. It would depend on the situation if both rear tabs broke.

• In a forward collision, the front tabs would keep the seat from moving forward, and the shoulder belts and left lap belt would prevent me and the seat from pivoting forward.
• In a rearward collision (if I went into something backwards, or got hit from behind) it literally can't move, since the front tabs would hold it in place and the bolts holding the rails to the frame are already jammed tightly against the floor. So it couldn't move backwards/down.
• The main risk is if the car flipped and the seat wanted to move upward, in which case the front tabs, shoulder belts, and left lap belt would mostly hold things in place. There could still be enough movement upward to put my helmet into the headliner, causing spinal injuries.
• The unknown is how much of the seat's mass would be restrained by the front tabs vs belts in the forward or upside down collisions. There's a possibility that I could be crushed against the belts by the seat during a high speed impact.

Fun times! Guess I'd better keep the rubber side down and try not to hit anything.

Torque Obsessed

Here's an update. I drove 2,200 miles in 4 days. (Atlanta to Wisconsin and back, for a track day at Road America.) Here are my observations after a lot of time in the R100 seat:

• The seat is still a bit too flat / too big for my taste. Not uncomfortable, just not wonderful either. I can drive all day (10+ hours) with no discomfort but I keep wishing it had more/different bolstering.
• There's nowhere good to put my left elbow because the side bolster is so big. I usually steer with my left hand, so this isn't a huge issue, but sometimes I had to think about where to put my left arm if I wanted to rest it.
• I would probably like the R100 better with the front raised up farther. I have a 3/4" spacer under the front of the seat now and might change this to a 1" or 1.25" spacer to get the front of the seat up higher. The orange big box store has nice metal cylindrical spacers which are perfect for this, in the section with the nuts & bolts.
• Corners and roundabouts are fun now. The side bolsters do a great job holding me in place when I throw the car around turns.
• On the track at Road America, the seat worked well. It's not a race seat by any means, but it's a thousand times better than stock. Overall it's a great compromise solution for street and track that works fine in both scenarios.
• Compared to the Sparco Evo II (same track, last year) I did notice that the R100 allows my upper torso to move a bit more even with the harnesses tight. In the Carousel I found myself bracing against the door, but more for comfort than anything else because it's such a long turn. I didn't notice or think about the seat anywhere else on track; it worked fine for me to stay focused on driving in all the other corners.
• I need to relocate the sub belt mounting locations. They are too far forward and I can't tighten the belts enough (I have them as short as they'll go already), so the center buckle was higher on my waist than it should be. I'll move the belt mounting points farther back under the seat and it should be fine.

So I think I can say that this is a solid choice. Not perfect, but a giant leap forward compared to stock and a great street/track solution that meets my needs.

D Griff

Wow, thank you so much for all of the great information! This is a fantastic write-up, and as someone who is desperately in need of a good seat solution for weekend/fun car/track toy hybrid seats, I think I may try this out. I was bummed at first as I'm similar weight but a couple of inches taller than you, but your "mods" might make it workable for me, I may also try a "foamectomy" (what the Miata world calls cutting out some foam in the back for lower seating position/more rake).

How would you say the height compares to the stock seats?