New seats

Well that was a long time.

I got out of the groove 5 years ago, the whole COVID lockdowns broke my routine of keeping the car Taxed and MOT'd and it's never got back to the top of the to-do list.

Some minor changes today - finishing off the seats upgrade. 

The original GBS ones from 2013 were worn out - vynil failing, padding not really doing its job and imobile storage not doing them any favours. I wasn't happy with my attempt at patching the bottom of the drivers seat area.

My new seats from Intatrim are narrower. 

I Decided to modify the mounting brackets vs. more holes in the cabin floor. The brackets aren't particularly pretty, it's focused on the simplest solution to keep everything rock solid.

An oil change and I suspect the brakes need at least exercising should be all thats between getting the car back on the road.

Countersunk seat bolts

I saw another builder with virtually flush seat mounts on the GBS Zero Owners & Enthusiasts Group, Looked much better than nuts/bolts on the outside and worth copying the approach.

Some Googling and searching on eBay turned up a whole line of undiscovered products designed for Go-kart seat mounting. Kart countersunk seat washers in alloy, nylon and titanium. Perfect.

My mount stack retaining the 50mm square washers inside to spread the load and thick washers above as spacers.

M10x25mm bolts were ok, 30-35mm would have been even better - my new learning for today is countersunk bolts are measured over their entire length including the head. I decided on alloy countersunk washers at about £5 for 10.

On the other side my initial thought was to use T-Nuts in the seat rail, so they cannot rotate when tightening - theres no room for a spanner in here. However - thinking through, not really keen on the robustness of these - I want my seats staying attached to the floor under all circumstances.

The option I decided on - especially since seat attachment strength is critical to safety - known good M10 nyloc flange nuts with flanges ground down so they fit inside the seat rail but cannot rotate. Should have been stainless really but I had none to hand.

Very fiddly to get the nut in place on top of the seat rail and tighten, but overall the finish looks much better to me.

Comparison part way through the job - passenger side closest with say 5mm or so below the floor pans, old style bolts still on the drivers side with at least 12-13mm for the nut alone. Looks tidy enough although the floor pans are not as flat as they used to be.

Hindsight and patience would have avoided my mix of metals - stainless bolt, BZP nut etc.

Drivers seat

Seat

The drivers side seat up next, theres less room to work due to the steering column & since the passenger seat is already in place.

The front edge is same as before - sliding the seat runners at fully forward (seat fully back position) - positioning the seat against the  back panel and marking the position of the front holes on the floor:

I then drilled the front positions with a 4mm pilot hole and lined up my template, taken from the underside of the seat, to locate the position of the rear holes. Those two M4 bolts in the front holes are just to line everything up:

The mounting bolts are M8, rear bolts dropped in fine, the front holes needed opening up a touch to let the seat rotate on the back bolts and let the front bolts drop into place:

This was a much better method than the passenger seat!

Seat belt

Reference shots of the belt mounting bolts:

The result - both seats & belts now installed:

Passenger seat & seat belt

Seats up next

I'm not using stock runners; mine have a locking mechanism on both sides & have been fitted to the seats for a while now. Theres not much room to position the seats - I thought I would start with the passenger side.

The seat is set at its rear most position on the runners with the back up against the rear panel should put it in the right place. I marked the holes by slipping some masking tape under the holes then drawing through their position with a pen,

Front pair first drilled to 8mm, then with bolts in the front holes and the seat slid forward on its runners the rear holes marked in the same way. With hindsight a template might have been a better option, and may be the only option on the drivers side due to lack of space. I had to widen my 8mm holes a touch to get the seat in place:

As per GBS instruction sheet, cap head bolt, lock nut under the rail & penny washer. Then under the car another penny washer & nyloc to hold everything securely in place. My wife helped holding the top bolt in place while I lay under the car to tighten them:

Seat belts

I'm using TRS belts, top loops need trim since they are an external part and too tight radius:

Picture of the belt's E mark for good measure - incase I need it at IVA:

Top bolts:

.. bottom bolts - incase IVA man needs to see them, I don't think I need covers on these the area behind the seats is exempt:

The result - smart!

I need to order some more nuts & washers then the drivers side is up next weekend.

Seat runners - trial fit

My seat runners arrived in the post; 

I thought they would need adjusting but I lucked out - perfect length, 330mm, and the adjuster bar just needed a little gentle bending to change from 290mm width as sold, to the 300mm width of the seats:

These were from Ebay/KDR Seating, now I have them in my hands they look identical to the CBS ones:

Of course - I don't have the right bolts to fit it to the car - I need some M8 40mm (possibly 30mm?) Cap head screws...

Interior - seats and tunnel top

Seats

I picked up the seats from GBS. Not currently fixed in because I want to try and find some seat rails which lock on both sides. The fixing centres on the GT seats are 300mm wide and 330mm front/back. Most runners seem to be too short so I may have to do some adjustment.

Nice seats though, ordered with red piping to match the nosecone & mudguards, finally I can sit in the car and get a feel for the space;

Tunnel top panels

Fitting the tunnel top panels, these took a little work - I decided to fix them in place with dome head bolts & 4x rivnuts per panel at each corner. I should have installed the rivnuts before the carpet really since with the extra thickness they didn't want to 'pull' correctly onto the tunnel panels & I wasted a couple in the process.

I also adjusted the gaps between the tunnel tops to have about 1mm gap which should allow the vinyl covering space to wrap over the edge of each one and still leave me with a good fit.

The brown cardboard is a mockup for a T7 heater. It will fit in the space provided I find an alternate location for the fuse box and route the wiring slightly differently. The heater will be recirculating - taking its air in from the cockpit - which I cant see as an issue since its all open anyway:

Seat belt mounting points

Just make sure I have these for IVA reference before it gets boxed in: