Seat Modifications

With a bit of courage, I took the seat to my local upholsterer and had them remove the cover from the seat back. After reassembling the seat, I cut away as much metal as I felt comfortable while careful not to compromise the seats structural integrity. Here is a pic at the end of the iterative pruning process.

A look at the seat back from the rear after dissection.

I added back a little metal for strength.

Cleaned up my welds.

Returned the seat-back to the upholstery shop for refitting.

This is my $60 flat fire wall alternative. Admittedly, I not deriving all the benes of a truly flat bulkhead. Although it feels great to have a seating improvement and have checked of a to-do that has been on my mind for 25years!

Thats a very neat job and the seats look sturdy and comfortable, It looks "Factory"

In fact its very impressive I might have a try at doing mine the same way. What a grand idea!

Peter, most of the right seat interference comes from the part of the bulkhead bulge that covers only the alternator. By repositioning the alt back 1" and driving it off the unused sheave of the A/C pulley, then notching the steel bulkhead cover as was done to the seat, the area of the right seat will be 'flat' against the rear firewall. The bubble part of the upholstered cover is separate from the rest of the big rear upholstery and can be pulled loose so the big bolted-in panel can remain in place while you remove only the (modified fiberglas) bubble-upholstery for front engine access. Most Gr-3 racers were rigged this way- possibly at the factory. The whole mod looks stock but is far more comfortable to drive or ride.

Alt. repositioning is simple, done with hand tools. You saw exactly 1" off the rear of the alt boss and use that as a spacer in front of the boss to mount the same alt 1" closer to the engine. No wire repositioning needed and the factory mount bolt fits. The alt adjust strap fastens to the rear of the same boss as stock, using the same small bolt. All this has been the subject of numerous illustrated Newsletter articles over the years. Last, take an old vee belt, cut it to exact size and use that as a model for your new belt. Vee belts are available in 0.060" increments but the way they're spec'ed is not straightforward.

Jack -

Pictures of this mod would be appreciated, if only for helping people understand your description. (Although maybe it should go in a new thread)

Most of the flat firewall mods I have seen use the "outboarded alternator" like my good friend Rocky did.

I would be interested in pictures of this less intrusive design.

Thanks -

Rocky

Nice work John!


Ron

Having recently had my rear "Firewall" plate behind the seats recovered, this seemed a good way of getting the passenger seat a little further back, without spending lots of spondooleys.

An ingenious out of the box solution and great execution by John, top notch. Many seats have a tubular frame rather than all steel buckets so worth checking how much effort would be required to modify your particular seat.

Maybe Jack can point us to a specific newsletter as they are archived on the POCA website now, albeit not indexed?

I for one am failing to see the full picture of cutting the alternator frame to move it rearward. Does it now run from a longer belt shared with the A/C compressor? OF course this mod still does not address the need to modify the steel hatch and bulkhead cover that would then require re-upholstering.

Julian