I have always found the standard seats have too much lumbar support which gives me backache on longer runs. This is what I did to over come this problem.

First remove seat and then remove backrest from the base.

Then unclip the upholstery at the bottom of the back rest.



Undo the 8 hogrings and you will see this.


Then you can peel back the leather until you cans see this.


You can see here where the lower part of the cushion is thicker, I marked where I roughly wanted to cut.

I then got a craft knife like this.


Then cut the foam CAREFULLY until you get something like this.


Once you are happy that you have cut the right amount of foam away to suit your own preferences, stretch the leather back over the cusion, What I did was use small cable ties on the upper 4 holes like this


On the lower 4 holes you need to pull the leather tighter so I did this..


The segment of foam that I removed I have kept in case I want to reverse the procedure.


Once finished assemble the back rest again an it should look like this..



This is only what I did, you may want to do things differently. It took me about 1.5 hours from start to finish.
I have yet to do a long run but just sitting in the car now feels like night and day from before.

Good Luck.

 

About 14 years ago my seat gave me a bad back in 2 mins I pulled the back rest bolster forward it only appears to be attached top and bottom and stuffed a bit of foam rubber about an inch thick in the bottom , it's still there and is fine . No sure why you would want to remove material to improve lumbar support ? But then you unusually had to much my physio at the time said the seat had poor lumbar support and needed more !

 

I use a lumber support cushion on my seat to help me on longer journeys, I used to have a small cushion made by Sparco but after losing that I got a neck roll cushion and trimmed it down a bit so it fits Into the small of my back, it might be better to add some foam to back but of course that might not suit SWMBO, I'll look into that idea.

 

I do exactly the same with some cut-up sofa foam. Has worked a treat for years and has the added benefit of being height adjustable for tall/short passengers.

 

All fair points, this is just what works for me, personally I found that the lumbar support felt like a lump in the seat back and it gave me very bad back ache, I even considered selling the car as a result. What this does for me is remover the "lump" and it feels much much better

 

Its def horses for courses. I get no backache but my ITBs are like wire cable and kill me on drives over an hour

My solution is yoga if i cba. I'm not flexible at all

 

I really struggled with my back in the standard seats on a long drive until I purchased some CG locks for both seats in a group buy on here. They pull your pelvis back into the seat and keep you firmly planted in the seat.
Great addition to the car and no more back ache.

 

Agreed, I do this on long journeys and track days. Really helps.

 

I bought some of these recently but haven't found they help with my particular back ache. Cushion works for me though I do get the odd grandad comment. I will be putting my pair of CG locks in the ‘for sale’ section, when I get around to it, or pm me if interested.