GSpeed Low-Profile Seat Mounts
 

THE NEED

When building a customer's BRZ racecar, we discovered the lack of purpose-built racecar seat mounts for these cars.

Since we have a 3D model of the interior of the car, we were able to design a seat mount that provides as much room for the driver as physically possible.

THE CONCEPT

http://www.gspeed.com/wp-content/upl...atmounts01.jpg

Starting with two of the largest race seats on the market (Racetech 119-series "Wide and Tall" variant), we moved the seats as low and back as physically possible. From this side profile, you can see there's not much room between the back of the seat and the body of the car:

http://www.gspeed.com/wp-content/upl...atmounts02.jpg

They're also slid as close to the transmission tunnel as possible to make sure even the widest seats can be centered on the steering wheel:

http://www.gspeed.com/wp-content/upl...atmounts03.jpg

Since it seems like no two race seat side mounts are the same, we've cut an assortment of slots in the top of the mount to allow for a myriad of mounting locations. It's inevitable some minor trimming may be required to get holes to line up, but it's either a perfect fit with ONE brand of seat, or 90% of the way there for every seat. Because we're a racecar shop, we chose the latter.

http://www.gspeed.com/wp-content/upl...atmounts06.jpg

This is the most secure mounting style.

http://www.gspeed.com/wp-content/upl...atmounts04.jpg

However, that doesn't always work. If you're building an endurance car with drivers of various heights, or you've got a street car and need to adjust your seat, you need sliders. These mounts have captive fasteners for, and can be purchased with, Recaro 0.79.9NT double-locking steel sliders. Adding less than an inch of seat height, this mount & slider combination is the perfect package for owners looking to get as much headroom as possible.

http://www.gspeed.com/wp-content/upl...atmounts05.jpg

THE PROTOTYPE

Here's the first pair we got back from the manufacturer:

http://www.gspeed.com/wp-content/upl...atmounts07.jpg

You can see we made a few changes, by comparing it to the rendered model above. Those changes were:

-Slot rear bolt hole. Although these bolted up perfectly to our 2015, it was brought to our attention that the earlier chassis had very slightly different rear mount locations. That shouldn't be an issue now.
-Widen seat mounting platform. We added over an inch to the total width on top to allow the seat to get a little closer to the tunnel. Even this wide Racetech is now centered in front of the wheel.
-Remove center "bridge." It limited how low the seat could drop, and we felt it wasn't necessary. As low as this mount is, it's incredibly stiff.
-Remove unnecessary slots in middle. Since these will most likely never be needed, we decided to remove them to cut down on laser time and keep cost low.

Here's how the seat sits in the car.

http://www.gspeed.com/wp-content/upl...atmounts08.jpg

You can see the roofline in that picture. For a car as small as this, it's incredibly spacious. The owner remarked he's got MUCH more headroom in this car than in any of his previous Viper racecars. The seat could have moved even further back if it wasn't for the roll cage.

PRODUCTION

These seat mounts are made from 11ga (0.12") carbon steel, with a black zinc phosphate finish that's both attractive and durable.

Each mount will be sold for $129.00 by themselves, and $233.11 with Recaro sliders.

Our current lead time for the first batch of 20 is three weeks. They're listed for sale on our website:

https://gspeed.com/product/brzfr-s86...ro-seat-mount/

Thanks!

i would love to test these for you if need be. i'm waiting to put in my Recaro Speeds (already have sliders) and am not thrilled with the only option being the planted tech bases. could also potentially use these in the Spec 86 race car not only in my daily brz.

keep us posted when they go for sale.

They're listed for sale here.

https://gspeed.com/product/brzfr-s86...ro-seat-mount/

We'll update with better pictures once we get the next batch in.

Will these work with stock seats?

No. The stock seats bolt to the uneven floor pan, which is the problem this product is intended to solve.

Here's a picture of the prototype installed in our test vehicle, with the added sub-strap attachment points to the floorboards below the seat.

http://gspeed.com/wp-content/uploads...0c6nwp0muh.jpg

If you're wondering why we didn't integrate harness attachment points to the seat mounts, it's intentional. We've had cars rejected from tech inspection that use the seat mounts to attach the harness, with good reason. Seat mounts shouldn't be harness attachment points.

Looking great, the design is a good improvement over the planted base:
- thinner
- recessed rear bolt location is exactly the solution that was needed to make the seat extra low

My only down is the center bridge which make lower belt setup "easier". Not the best location but at least it works for those of use who don't want to weld anchor point to the bottom of the car. Personally I prefer the sub belt to be attached to the seat rather than the chassis, as I have no idea what part of the chassis offer strong support or not.

Overall, looking great, again the low profile that's what it is all about on this car.

Forgot to mention, at $129 they are VERY attractively priced. Way to go, now if you could show some seat bracket that you recommend as well, that would help to buy a full kit. I personally struggled finding good seat brackets.

Very nice product and pricepoint.

What are your thoughts on mounting this to roll cage instead of floor pan?

I have long since thought that the driver and all driver safety items should be mounted to the cage so they all move and react in unison. If the floor were to get a big hit, suddenly the harness would be loose on the bottom.

As you'll see above, that's intentional. Installing a sub-strap (aka "crotch strap") to the seat or its mount is not a safe install method. The seat should be supporting nothing but the driver, and attaching straps to the seat mount now puts those tensile forces into the mount. Passing those loads to the chassis directly is very easy and makes the seat mount MUCH safer.

The seat side mounts are going to vary by seat. Cobra, Sparco, Racetech, all sell their own side mounts since they all have different bolt patterns in the seats themselves. It's inevitable the seat mounts will align with the slider or base differently.

For a slider, it's theoretically possible for us to make any modifications to the side mounts to bolt directly to the slider before they ship, if you were to order the seat, mounts, and sliders from us. There'd be a labor charge, of course, but it would be a bolt-in setup once it arrived.

I can understand why some pro cars are built that way, but most club racing rule series would disallow that many cage attachment points. Not to mention, when properly reinforced (6 in² or so) I haven't seen any harness attachments pull through the unibody.

Would it be stronger? Sure, there's more steel involved. Is it necessary? In our professional opinion, no.

@GSpeed good feedback.

I was actually thinking that if you bounce the floor pan off a curb or something and you get a 1" dent, suddenly the seat is up higher and the harness gets way tighter, or the harness is way looser.

Interesting to hear your feedback. We considered doing this with our Lemons Fiero since it has no transmission in the way, and one of our drivers is 6'8". We figured it would allow us to lower the floor pan and reduce it's structural concerns, and box out the area. We ended up going with ultra-low seat mounts, and pushing the pan down just a bit, and shortening the pedals. I still think a caged seat mount would of been awesome.

Yeah, there's nothing inherently wrong with doing it that way. We would have no problem doing that on a customer car if required. In fact, some Trans Am cars we work on are built exactly that way (tube frame chassis).

Just a note:

Check with your local sanctioning body/class rules, I don't know of any that allow a race seat to be mounted on sliders.

We won't be running sliders, but these mounts are designed to make it easier for guys running street cars.

I've heard of some LeMons guys running sliders with an adjustable back brace in endurance races.

Jake

After being back-burnered for a few months, these seat mounts are now for sale. We've installed a pair in Jonsey's car to hold his new Sparco seats in place.

https://gspeed.com/wp-content/upload...atmounts10.jpg

A few other sets have gone out to other members, and everyone is happy with them! Especially the tall guys that need as much room as possible. ;)

https://gspeed.com/product/brzfr-s86...ro-seat-mount/