Adapting MX5 seats

[hogster]

If anybody out there has photos of how they adjusted the seat runners on their MX5 seats to fit their cobra I would be really interested thanks.

Written explanantions are also good.

Got my seats today and I am a little perplexed as to how I am going to fit them. The bulge under the seat base is the issue. If I build up the runner height, my legs will hit the steering wheel.

What sort of clearance distance do you guys have from floor to the top of the seat and from floor to the bottom of the wheel??

Thanks

[stephen low]

Hogster

I literally modified the width of my MX5 seats but as the G Force floor is raised around the edge and the rear attachment of the runners is located on this ledge I have too much clearance. I will be investigating post rego. how I can reduce the height!

Given the ease I had narrowing my seats i reckon you should consider simply lopping part of that buldge off.

This will loose you padding depth under your butt however I don't think it would be too hard to replace the sheet steel you cut off with something similar but flat. This could be spot welded or even rivetted back in place.

I had my pan spot welded on either side of the narrowing joint and then took the opportunity to spray the whole pan to eliminate the issue of rusting. Mine had surface rust when I got it - a common complaint for these seats -and I had come accross at least one pan in my earlier search that had rusted out!

I think there are some pics. in my gallery of the seat mods. I did but if not I can forward you some pics. if you like. It's not what you are looking to do but you will be able to see the bare pan. I should have said that the pan foam is one piece and just sits in place and can be removed.

Cheers

[400TT]

How hard is it to recess the floor, that's the way we went in our old DRB.

We didn't recess the entire floor, just enough to clear the seat sliders etc.

So you would be cutting out the centre area where the seat sliders and pan is. So effectively the edges of the seat would be a few mm above the floor(allowing for carpet of course). You would then effectively be welding in a dropped box like pan into the floor.

The more you take out of the seat, the less comfortable they get.

Plus it sounds like you are sitting quite high, lowering the seat gets you lower on the screen and more leg room under the dash. The more leg room under the dash also gives you the ability to fit longer drivers in. We sat higher in the DRB, but had more length to the pedals. With the Harrison we sat lower but had less length to the pedals, but it worked out you could get the same amount of comfort in both cars for longer drivers. Plus the more clearance under the dash gives you more freedom to move/bend legs on long trips.

From memory on our MX5 seats we just cut/bent the mount tabs so they were flat, then affixed flat steel straps between them to adapt to the Harrison seat mount cross braces.

[stephen low]

Hogster

What Craig says is right.

Bent my runners flat and cut off the locationing spikes and mounted to steel plates running across the cockpit at front and rear.

If you shallow the pan you loose padding, if you can lower the seat all the better! As said previously the GF floor is raised around the edges and lowered in the centre but you can't get mounting locations in the centre. Well not yet anyway.

Aside from keeping weight down, also remember to not over do the thickness of steel supports. I used 3mm plate steel, thick enough for strength but thin enough to shear under major impact. A good engineer might be on the look for this, as it is intrinsic to better crash protection.

Hope you're having fun with your jigsaw too!!

Cheers

[400TT]

Well I thought I might have photos of the modified MX5 seat mounts.

This is all I have.



Pretty isn't it.

Notice no Cobra body/chassis in background. This is in the before chassis stage of the build. We had all drivetrain, suspension and lots of little things ready to go well before the chassis arrived. So all those guys waiting for chassis before starting the build, you can well and truly start your build without one.

Sorry don't have photos handy of DRB floor mods, they were done 10+ years ago before we had luxury and convenience of digital.

[hogster]

Thanks for the advice guys

I cant drop the seat into the floorwell because I have a major beam running across right under the seat.
I will have to just have go at cutting out the bulge in the seat base.

If I still have an issue with leg clearance I will have to raise the wheel/column or use a plastic wheel off a toy car

Hogster

[400TT]

That's a bugger.

On the DRB we also raised the column and moved the steering wheel towards the dash to help with arm length, but this also made a difference to leg clearance. When you think about it, the closer the steering wheel is to the dash, the more effective clearance you have for driving and entering/exiting.