Long Road to Safety: Roll bar & Harness Install in Z4 Coupe

[3002 tii]

I first installed my Recaro PP 2 years ago. In terms of hardware, I went with Recaro universal side mounts and sliders, Macht Schnell seat belt receptacle adapter & floor mounts, and a seat belt extender. Using an extender would bring the factory belts back to the original geometry or closest as possible in order to prevent any submarining effect.

General tips, try to get the seat as furthest inboard (to trans tunnel) as possible as that will get you more centered to the steering wheel and prevent any rubbing with the door panels. Play with different seat angles before bolting anything down because adjusting the angle afterwards will be a real pain. I found angling the front higher than the rear provides good support for performance driving. And lastly, despite getting all the "right" hardware always have tools ready to modify any seat hardware as things never line up as intended.


(~3/4” clearance from door)


(belt extenders allow lap belts to remain tight)

I was able to get past the seat belt light using an eBay emulator. While the belt extenders got the job done, I honestly never felt 100% comfortable on track with this setup since didn't have any rollover protection and really wanted to use a HANS. After witnessing 3 friends wreck their cars, I decided for 2014 I would take the dive and get a half cage and run harnesses. The cost would be very high but it just seemed worth it.

I researched for months for different Z4 cage & harness designs. My ultimate requirements were:

a) compliant with NASA, CCA, PCA guidelines
b) car would remain street legal
c) minimal interior modification

While a few designs met the criteria, I thought Tonybest's car was by far the most impressive. Tony was kind enough to put me in touch with his builder Seb. The plan was to ship my car north across the border. I would then buy a one way ticket and drive back down. But after crunching the numbers, this would push the total cost way over my budget and put me behind the track season.

Thus I got in touch with Artisan Research in PA. Their work is top notch and I knew they could build anything I had in mind. AR decided it was best to retain the factory belts instead of doing away with them. However, we could no longer use the factory receptacles because the pretesioner design takes up too much space. There would be no way to fit both the factory receptacle AND the lap belt from harnesses in between trans tunnel & seat. So what we did was purchase E30 receptacles which is just buckle without pretesioner and place them where the factory receptacles originally sat.


(Passenger side, original receptacle zip tied behind seat)

In order to prevent the airbag light tripping, I still kept the factory belts plugged into the seat harness. We zip tied those to the lower portion of the roll bar and plugged the emulators I had from the very beginning. I also clipped in the belt extenders so I wouldn't get the seat belt chime neither. Now airbags will still function, no light on the dash, and I can still use factory belts when I'm driving to/from track.

Here's the final product

[Finnegan]

Very nice, and very smart given the amount of track time and limits you're now running at. Looks downright impressive and cool on top of that! It's nice to see the quality work being done for Z4s.

Costs a pretty penny but worth it IMO.

[3002 tii]

Originally Posted by Finnegan

Very nice, and very smart given the amount of track time and limits you're now running at. Looks downright impressive and cool on top of that! It's nice to see the quality work being done for Z4s.

Costs a pretty penny but worth it IMO.

Thanks Fin, getting past the cost was doable after I realized what one bad wreck could really cost me. Believe it or not the hard part was accepting the fact that the mod wasn't reversible but I plan to keep her as long as possible

[Vanne]

Wow beautifully done mate. More shots of the cage where it's bolted to the frame please.

[3002 tii]

Bump... all this talk about roll bar and harnesses in the track section, I was able to dig up old photos taken by my fabricator. Sorry for low quality images, these were from ~5 years ago.

[3002 tii]

More pics

[3002 tii]

And install

[eggman51]

Just stumbled across thius now, those are great pics, thanks for updating the old thread with great pics - much appreciated.