What’s your favorite aftermarket seat?

Recaro SPG XL.  One of the few I fit into since I'm all torso.  I need really large, high, shoulder harness holes so the harnesses/holes are above the level of my shoulders.

Definitely going to be my Sparco Evo XL QRT. Amazingly enough I was able to fit it into my NC Miata without a hammer to the car. Seats are always one of my favorite changes to a car.

For an amazingly-comfortable daily driver/long road trip seat that also works for autocross and occasional trackdays, I love my scheel-mann Sportline R with adjustable lumbar support. I am totally affiliated, as I work at scheel-mann usa. The enthusiasm is genuine as seeking out these seats is part of the story of how I landed my current job.

OMP HTE-R, because its a containment seat, with certs,  that actually fits in a Miata without too much fuss. Wouldn't want to daily any "real" racing seat, but maybe I'm just getting old.

On the other hand, I have an affinity for old E36 M3boxes as daily drivers, but have always wondered if it were possible to (easily) swap out to better seats. Something like a (junkyard) Volvo seat in a Corolla. Do adapters/rails/etc exist to make that happen?

In reply to spedracer :

It depends. The market for bolt-together XYZ stock seat into ABC vehicle adapters is fairly niche, and only a few examples exist on the market.

If we ignore the junkyard stuff for just a second, the typical aftermarket setup for an adjustable seat is a universal seat as one part, a brand-specific set of sliders matched to the seat, and then a vehicle-specific adapter bracket. 

The interface between sliders and adapter brackets are typically one of two styles, tab or flat. The two big players in the bracket game (Planted and Wedge, and "Corbeau" is also Wedge) make brackets to fit a specific vehicle, and the brackets for a given vehicle all start out the same and they just move the holes or tabs around on those brackets to match up with your chosen aftermarket seat/sliders.

Back to the junkyard stuff. There isn't any consensus among manufacturers how the seat and base assembly is designed and put together, which can make swapping seats a heavy fabrication project. Some of them are all one unit, and the separable parts are seat assembly and vehicle floor. Not very friendly to swapping. Others integrate the sliders into the seat, and the base is separate. Others integrate the sliders into the base and the seat unbolts (I'm looking at you, Dodge!) With so many variations in design, height, width, bolts, welds, rivets, etc, making adapters is complex. Sliders can have the female part on the seat side and the male part on the vehicle side or vice versa. The general concept of sliders is almost always the same, but the dimensions vary quite a bit.

If you get an aftermarket seat bracket from Planted for flat sliders, the top of the bracket is essentially a flat plate, which is probably about as friendly as it gets for swapping, with several caveats. If the seat plus sliders can be unbolted, air-chiseled, or angle-ground from the rest of the base, and they can be attached in a manner that can withstand the potential forces of a crash (way higher than many people think...pull tests are insane!) an aftermarket bracket may be an option...but you also have to keep seat height in mind, which is an important ergonomic factor. Seat bottom cushion thickness/angle  varies, so spacers may be needed. Remember that you can go higher with spacers, but getting lower if bracket is too tall involves a new bracket or a lowered floor.

The aluminum race seats; I'm really small and these allow me to make a custom insert that form fits me.

In reply to ae86andkp61 (Forum Supporter) :

Damn, exactly what I was worried a out - doable but a huge project. My dreams of having a beater daily but with modern/comfy seats sounds like it ain't happening anytime soon!

Another one for the OMP HTE-R seat. We love it in our Elantra. Fits all drivers, has FIA certs and is quite comfortable over a 2 hour stint. 

Brand really doesn't matter. Getting one that fits you the best is the main criteria. I've had race seats, and I've had race seats that fit me properly. No comparison.

In reply to ae86andkp61 (Forum Supporter) :

I've known about Scheel-mann seats for trucks, but hadn't thought about them for cars. 

Is there a decent website for dimensions and whatnot?